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I
Buildability Concept Influencing Quality of Building during
Design Process in UNRWA Projects
أثر "قابلية البناء " علي جودة البناء خالل عملية التصميم في مشاريع األنروا
Researcher:
Mohammed A/Ghaffar Abbas
Supervised by:
Dr. Nabil El Sawalhi
A thesis is submitted in partial fulfillment of requirement for the degree of Master of
Science in Engineering Projects Management
The Islamic University of Gaza
Palestine, 2014
The Islamic University -Gaza Higher Education Deanship Faculty of Engineering Engineering Projects Management
الجامعة الإلسالمية-غزة عمادة الدراسات العليا
كلية الهندسة إدارة المشروعات الهندسية
II
قال تعالي
ومن أحسن قـوال ممن دعا إلى اللـه وعمل صالحا (
33 فصلت )إنني من المسلمين وقال
III
DEDICATION
In the Name of Allah, the most Gracious, the most Merciful
This thesis is dedicated to:
The memory of my late beloved father (May Allah grant him eternal rest,
Aameen), and to my affectionate mother”.
M y wife, for her continuous inspiration and support.
My kids were they missing my direct care during my study.
IV
AKNOWLDEGMENT
I would like to express my grateful thanks to my supervisor Dr. Nabil El
Sawalhi for his valuable advice, and guidance on this master thesis
throughout the study period.
Deepest appreciations for construction management staff at the Islamic
university-Gaza for their academic and scientific supervision
Finally, gratitude to my colleagues in infrastructure and camp
improvement programme in UNRWA for their participation in filling the
questionnaires, and giving information that supported the case study.
V
ABSTRACT The design process is considered as the most important stage in the project life cycle. Throughout this stage the level of involvement between design and construction team will affect the building quality. There are many problems occur during construction where building could not be built as designed, schedule plans, cost plans, and client satisfaction. It is important to improve the design process by considering the buildability approach to keep project performance as well as reducing the construction time and improving quality. The research aim to investigate the buildability during the design stage, which could improve the project performance as well as the project schedule and increase the quality of building during of the operation and maintenance stages in UNRWA projects in Gaza. The research objectives are to explore the buildability concept influencing quality of building design, identify the factors that causes buildability problem due to designers, identify the factors that influencing of the design process, to explore the project components weighting in UNRWA projects and to explore the Faced finishing material affecting buildability of building design. The objectives of this study were achieved throughout three approaches. First, the structured interview to explore and identify the most effective factors, and level of knowledge in buildability. Second, a valid questionnaire that was obtained from professional engineers in UNRWA. Third, the case study for three actual projects, two schools and one health center were analyzed. The results showed that the buildability concept that influencing the quality of building design are: coordination of design information; use material based on availability on local market; and the site conditions should be investigated to avoid subsequent delay. The main factors that causes buildability problem in design stage are due to lack of education and training on buildability, and no documentation for the lesson learned that arising from maintenance field. The result showed the most important factors that influencing the design process; are: check that the design considers the contractor available resources; the effect of code and standards on quality of design; sharing the knowledge of other professionals; teamwork during the design stage and check that the designs consider the energy efficient building. The study recommended that designers should be involved during impelimintation process with close co-operatioin between other project participants. In addition develop a check list system considering the principle of buildability. Moreover, training the desginer to produce buildable desgin.
VI
ملخص البحث
جودة المبني من حیث تساھم في تحدید في دورة حیاة المشروع، احل مرالأھم من تعتبر عملیة التصمیم
ي تنفیذ عدم القدرة علھناك الكثیر من المشاكل التي تنتج عن . التنفیذتصمیم وخالل مدي التواصل بین فریق ال
.المشروع وتكالیفھ ومستوي رضي المالكحیث یؤثر ذلك علي جدولھ ،المشروع وفق ما تم تصمیمھ
ھدف المشروع وبالتالي تحقیق البناء بھدف تطویر عملیة التصمیم من اجل یة من الضروري مراعاة امكانانھ
.تقلیل زمن المشروع وتحسین الجودهمع العمل علي مستوي أداء المشروع الحفاظ علي
یة التصمیم والتي بدورھا تؤثر علي جودة أداء المشروع یھدف البحث لدراسة مدي امكانیة البناء من خالل عمل
.التشغیل والصیانھ في مشاریع األنروا وذلك أثناء
كانیة البناء والتي تتعلق بالمصمم والبحث في العوامل التي كما یھدف البحث الي التعرف علي المعیقات في ام
لمشروع في األنروا وكذلك التعرف علي مواد تؤثر في عملیة التصمیم، كما یھدف البحث للتعرف علي مكونات ا
. التشطیبات التي تؤثر في امكانیة البناء عند تصمیم المبني
األكثر تحدید العوامل الستكشاف و المقابلةتنظیم . وقد تحققت أھداف الدراسھ من خالل استخدام ثاللة مناھج
وقد .األونروا في المھندسین المتخصصینھ من لمجموع استبیانالبناء وعمل قابلیة فيمستوى المعرفة فعالیة و
.مركز صحي ووھم عبارة عن مدرستین مشاریع ثالثةل دراسة حالة تم تحلیل
البناء قابلیة عوامل أظھرت النتائج أھمیة التواصل في المعلومات التصمیمیة بین فریق التصمیم والتنفیذ كأحد أھم
واستخدام مواد ،تبادل للخبرات واالستفادة من التجارب السابقة ینتجمما التي تؤثر علي جودة تصمیم المبني
.أي تأخیر غیر مبررلتجنب وكذلك دراسة وتحلیل ظروف الموقع ،متوفرة في السوق المحلیة
وقد أوضحت الدراسة أن ،البناء للمصممقابلیة ومن نتائج البحث ایضا تحدید العوامل التي تتسبب في معیقات
عدم توثیق بالإلضافة الي ،أكثر العوامل تأثیرا علي معیقات امكانیة البناء من معلوماتنقص التدریب وال
.اإلداريوكذلك عدم اإلستجابة الفعالة من قبل الطاقم ،الدروس المستفادة من قبل قسم الصیانھ
رورة أن ان یشارك المصمم في اإلشراف علي المشروع أثناء عملیة التنفیذ مع ض ضرورة اوصت الدراسة علي
فریق العمل بھدف تطبیق تفاصیل ومواصفات موحدة للمشاریع بھدف أفراد یكون ھناك عالقة تواصل مع جمیع
قابیلة واألخذ باإلعتبار مبدأ یة تطویر عملیة المراجعة على أھمكما أوصت الدراسة ،تقلیل الوقت والتكالیف
.انتاج تصمیم یكون قابل للبناء علىلفریق التصمیم البناء، كما أوصت الدراسة بعمل تدریب
VII
Table of content DEDICATION……………………………………………………………………III AKNOWLDEGMENT…………………………………………………………....IV
ABSTRACT .............................................................................................................. V البحث ملخص ................................................................................................................ VI
TABLE OF CONTENT ................................................................................................ VII LIST OF ABBREVIATIONS ............................................................................................ X LIST OF TABLES ........................................................................................................ XI LIST OF FIGURES .................................................................................................... XIII
CHAPTER 1 INTRODUCTION ................................................................................... 1
1.1 BACKGROUND ....................................................................................................... 1 1.2 RESEARCH PROBLEM ............................................................................................. 1 1.3 RESEARCH JUSTIFICATION ..................................................................................... 2 1.4 AIMS OF THE RESEARCH ........................................................................................ 2 1.5 OBJECTIVES OF THE RESEARCH ............................................................................. 2 1.6 RESEARCH QUESTIONS .......................................................................................... 2 1.7 HYPOTHESIS .......................................................................................................... 3 1.8 SUMMARY OF RESEARCH METHODOLOGY ............................................................. 3 1.9 RESEARCH SCOPE AND LIMITATION ....................................................................... 4 1.10 EXPECTED RESULTS............................................................................................. 4 1.11 RESEARCH STRUCTURE ....................................................................................... 5
CHAPTER 2 LITREATUR REVIEW........................................................................... 7
2.1 INTRODUCTION ..................................................................................................... 7 2.2 DEFINING BUILDABILITY ....................................................................................... 7 2.3 COMPARISON BETWEEN CONSTRUCTABILITY AND BUILDABILITY ......................... 8 2.4 THE PRINCPLE OF BUILDABILITY ........................................................................... 9 2.5 THE BUILDABLE DESIGN APPRAISAL SYSTEM (BDAS) ........................................ 11 2.6 THE BENEFIT OF BUILDABILITY ........................................................................... 12 2.7 THE KEY AREAS OF BUILDABILITY ...................................................................... 15 2.8 GUIDELINES FOR GOOD BUILDABILITY ................................................................ 15 2.9 FACTORS AFFECTING BUILDABILITY ................................................................... 18 2.10 FACTORS CAUSE BUILDABILITY PROBLEMS ....................................................... 21 2.11 IMPROVING BUILDABILITY AT THE DESIGN PROCESS ......................................... 22 2.12 BUILDING PERFORMANCE CRITERIA .................................................................. 24 2.13 BENEFITS OF MEASURING BUILDING PERFORMANCE ......................................... 24 2.14 THE RIBA PLAN OF WORK ................................................................................ 25 2.15 VARIABILITY FACTORS IN THE MANAGEMENT OF DESIGN PROCESS ................... 27 2.16 THE DESIGNER TEAM ROLES FOR QUALITY OF DESIGN ....................................... 29 2.17 THE DESIGN QUALITY CONSIDERATION ............................................................. 30
2.17.1 The steps to achieve the design quality ..................................................... 31 2.17.2 The benefits of design quality ................................................................... 32
2.18 PRODUCTIVITY CONCEPT IN CONSTRUCTION INDUSTRY .................................... 32 2.19 QUALITY FUNCTION DEPLOYMENT AND BUILDABLE DESIGN ............................. 33 2.20 CHAPTER SUMMARY ......................................................................................... 34
VIII
CHAPTER 3 RESEARCH METHODOLOGY .......................................................... 35
3.1 INTRODUCTION ................................................................................................... 35 3.2 RESEARCH TECHNIQUES ...................................................................................... 35
3.2.1 Literature review ......................................................................................... 36 3.2.2 Questionnaire .............................................................................................. 36 3.2.3 Structured interview .................................................................................... 37 3.2.4 Case study ................................................................................................... 37
3.3 QUESTIONNAIRE DESIGN ..................................................................................... 39 3.4 RESEARCH PERIOD .............................................................................................. 40 3.5 RESEARCH LOCATION ......................................................................................... 40 3.6 DATA COLLECTION ............................................................................................. 40 3.7 RESEARCH POPULATION AND SAMPLE SIZE ......................................................... 41 3.8 QUESTIONNAIRE CONTENT .................................................................................. 41 3.9 PILOT STUDY ....................................................................................................... 41 3.10 VALIDITY OF RESEARCH .................................................................................... 42 3.11 CONTENT VALIDITY OF THE QUESTIONNAIRE .................................................... 43 3.12 STATISTICAL VALIDITY OF THE QUESTIONNAIRE ............................................... 43 3.13 CRITERION RELATED VALIDITY ......................................................................... 43 3.14 STRUCTURED VALIDITY OF THE QUESTIONNAIRE .............................................. 48 3.15 RELIABILITY OF THE RESEARCH ........................................................................ 48 3.16 HALF SPLIT METHOD ........................................................................................ 49 3.17 CRONBACH’S COEFFCIENT ALPHA .................................................................... 50 3.18 STATISTICAL MANIPULATION ............................................................................ 50 3.19 CHAPTER SUMMARY ......................................................................................... 51
CHAPTER 4 ANALYSIS AND DISCUSSIONS ....................................................... 52
4.1 INTRODUCTION ................................................................................................... 52 4.2 GENERAL INFORMATION ..................................................................................... 52
4.2.1 Position of respondent ................................................................................ 52 4.2.2 Years of experience in the construction industry ........................................ 53 4.2.3 Academic qualifications .............................................................................. 54 4.2.4 The major of the sample experience ........................................................... 54 4.2.5 Years of works in organization ................................................................... 55 4.2.6 Term of buildability main impact ................................................................ 55 4.2.7 The design process and quality of building performance ........................... 56
4.3 ONE SAMPLE K-S TEST ....................................................................................... 57 4.4 DISCUSSION AND HYPOTHESES TEST ................................................................... 57 4.5 BUILDABILITY CONCEPT INFLUENCING QUALITY OF BUILDING DESIGN ............... 58 4.6 FACTORS THAT CAUSES BUILDABILITY PROBLEM DUE TO DESIGNERS ................. 59 4.7 FACTORS THAT INFLUENCING THE DESIGN PROCESS ............................................ 61 4.8 PROJECT COMPONENT WEIGHTING ...................................................................... 64 4.9 FACADES FINISHING MATERIAL AFFECTING BUILDABILITY OF BUILDING DESIGN 65 4.10 ONE WAY ANOVA ........................................................................................... 67
CHAPTER 5 INTERVIEW AND CASE STUDY ...................................................... 69
5.1 STRUCTURED INTERIEW ...................................................................................... 69
IX
5.1.1 Introduction................................................................................................. 69 5.1.2 Interviews finding........................................................................................ 70
5.2 CASE STUDY........................................................................................................ 72 5.2.1 Introduction................................................................................................. 72 5.2.2 Case study (A): Health Center .................................................................... 72 5.2.3 Case study (B): School No.1 ....................................................................... 72 5.2.4 Case study (C): School No.2 ....................................................................... 73 5.2.5 Data collection ............................................................................................ 73 5.2.6 The case study finding ................................................................................. 74 5.2.7 The major findings of the case studies are summarized as follows:- ......... 76 5.2.8 Summery 77
CHAPTER 6 CONCLUSION AND RECOMMENDATIONS .................................. 78
6.1 INTRODUCTION ................................................................................................... 78 6.2 CONCLUSION ....................................................................................................... 78
6.2.1 The buildability concept to have a high quality of building design ............ 78 6.2.2 Factors that causes buildability problem due to designers ........................ 79 6.2.3 Factors influencing in the design process .................................................. 80 6.2.4 Facades finishing material affecting Buildability of building design ......... 80
6.3 RECOMMENDATION............................................................................................. 81 6.4 RECOMMENDATIONS FOR FUTURE STUDIES ......................................................... 81
REFERENCES ............................................................................................................ 82
APPENDICES……………………………………………………………………….89
Apppendix (1)…………………………………….………………….…….………. 89
X
List of abbreviations
CIRIA Construction Industry Research and Information Association
CII Construction Industry Institute
BDAS Buildable Design Appraisal System
RIBA Royal Institute of British Architects
GDP Gross Domestic Product
QFD Quality Function Deployment
CM Construction Manager
CEM Construction Engineering Management
TQM Total Quality Management
ANOVA One Sample Analysis of Variance
SPSS Statistical Package for the Social Sciences
UN United Nations
UNRWA United Nations Relief and Works Agency
ICIP Infrastructure and Camp Improvement Programme
UK United Kingdom
USA United State of America
XI
List of Tables Table ( 2-1): Design for disassembly principality from buildability research (Crowther,
2002) ............................................................................................................................ 10
Table ( 2-2) Factors affecting buildability (Wong et al. 2004) ..................................... 18
Table ( 2-3): The RIBA plan work (Othman, 2011) ..................................................... 25
Table ( 2-4): Design management recommendation (Rounce, 1998) ........................... 27
Table ( 3-1): Questions scale ........................................................................................ 41
Table ( 3-2): The correlation coefficient for buildability concept influencing quality of
building design ............................................................................................................. 44
Table ( 3-3): The correlation coefficient for factors that cause’s buildability problem
due to designers............................................................................................................ 44
Table ( 3-4): The correlation coefficient for factors that influencing in the design
process.......................................................................................................................... 46
Table ( 3-5): The correlation coefficient for facades finishing material affecting
buildability ................................................................................................................... 47
Table ( 3-6): Structure validity of questionnaire ........................................................... 48
Table ( 3-7): Half Spit coefficient method .................................................................... 49
Table ( 3-8): Reliability Cronbach’s Alpha .................................................................. 50
Table ( 4-1): Position of respondent ............................................................................. 53
Table ( 4-2): Academic qualification ............................................................................ 54
Table ( 4-3): The major of the sample experience ........................................................ 54
Table ( 4-4): The percentage of involvement ............................................................... 56
Table ( 4-5): One Sample K-S ...................................................................................... 57
Table ( 4-6): Buildability concept influencing quality of building design ................... 58
Table ( 4-7): Factors that cause’s buildability problem due to designers ..................... 60
Table ( 4-8): Factors that influencing of design process............................................... 62
Table ( 4-9): Project component weighting .................................................................. 64
Table ( 4-10): Facades finishing material affecting buildability of building design .... 65
Table ( 4-11): Facades finishing material affecting building of design "Roof/Slab
covering" ...................................................................................................................... 66
Table ( 4-12): One way (ANOVA) of difference in point of views of due to position of
respondent .................................................................................................................... 67
XII
Table ( 4-13): One way (ANOVA) of difference in point of views of due to experience
...................................................................................................................................... 68
Table ( 5-1): Profile of interviews ................................................................................ 69
Table ( 5-2): Summary of Case Studies ........................................................................ 74
Table ( 5-3): Factors that causes buildability problem due to designers (case study) .. 76
XIII
List of Figures Figure ( 2-1): The wider framework of buildability (CII, 1993) .................................... 8
Figure ( 2-2): Optimum design input (adapted from Saghatforoush et al. 2011) ......... 13
Figure ( 2-3): Construction project phases (Thabet, 2006) ........................................... 15
Figure ( 2-4): Life Cycle costing profile (adapted from Saghatforoush et. al. 2011) ... 23
Figure ( 2-5): Steps that a client can take to achieve design quality in a project.......... 31
Figure ( 2-6): Customer and their requirements of buildable design ( Yanga et al.
2003) ............................................................................................................................ 34
Figure ( 3-1): Methodology flow chart ......................................................................... 38
Figure ( 4-1) Years of experience in the construction industry .................................... 53
Figure ( 4-2): Years of works in organization .............................................................. 55
Figure ( 4-3): Term of buildability main impact ........................................................... 56
Figure ( 5-1): Project component weighting ................................................................. 75
Figure ( 6-1): The buildability concept to have a high quality of building design ...... 79
1
Chapter 1 INTRODUCTION
1.1 Background The construction industry has an important role in the economic activities in Gaza
Strip. The construction industry is still one of the highest costly and important
industries that can’t be excluded. It is one of the main industries that are supporting
GDP and it influences on our daily life. In construction industry, there are a many
problems occurred during construction where building could not be built as designed,
schedule plans, cost plans, and client satisfaction. It is really important to improve
the design process to keep project performance as well as reducing the construction
time and improving quality.
Any client would want to construct a facility of the highest quality, and it is the goal
of the project team to maximize quality while minimizing cost and time. Therefore,
this will give satisfaction to all the parties of a building project - client, design team
and construction team.
Buildability concept must be considered from the initial preliminary design and
discussed the requirement into the design by the clients. Identification of the client’s
needs and objectives will enable the designer to use of experienced construction
knowledge from the outset to the completion of a project. It is recommended that
integrating methods of construction into the design process is providing benefits and
solutions to achieve the design intent in a cost effective and timely manner.
1.2 Research problem Shortage in construction material considered as the main problems in the
construction industry in Gaza Strip. Therefore, buidability approach and review the
design should minimize or eliminate potential change orders and delay claims during
construction by ensuring that the construction documents are fully coordinated,
complete, and buildable by achieving the best value of building performance. This
research will focus on the buildability concept. The impacts of the project
performance during the construction phase of project were investigated.
Identification of the key principles of buildability concept during the design process,
and identifies the benefit of the major concepts that give maximum opportunity to
deliver a high quality project on time and at the agreed cost.
2
1.3 Research justification The construction project development involves numerous parties, various processes,
different phases and stages of work and much of input from both the public and
private sectors. The major aim is to bring the project to a successful conclusion. The
design stage is the critical in the building development process. The design decisions
affect how a building is to be built. Hence, by doing the job right at early schedule
plan, the total project cost can be reduced substantially by identifying mistakes,
analyzing the situation and solving any problem. Any extra cost means huge losses to
the contractors and higher expenses to the clients. To avoid such loss in construction
rework, extensive research on buildability needs to be conducted to improve the
construction process. Buildability concepts and principles must be considered from
the conceptual design at an early stage in the total construction process. The
industry’s clients are continuously demanding the best value for money, in terms of
the efficiency with which the building is carried out. The integration of good
buildability into good overall design is the responsibility of the design team.
1.4 Aim of the research Improve the design process as well as the project schedule and increasing the
quality of building during the operation and maintenance stages.
1.5 Objectives of the research Explore the buildability concept influencing quality of building design.
Identify the factors that causes buildability problem due to designers.
Identify the factors that influencing of the design process.
Explore the project components weighting in UNRWA projects.
Study the key facade finishing material affecting buildability of building
design.
1.6 Research questions
In order to achieve the above aim and established the objectives, the following
questions to be addressed:
What are the project benefits of improved buildability?
3
What are the current difficulties occurred during construction where buildings
or facilities could not be built as designed?
What are recurrent construction problems that could designers reduce or
avoid?
What are the most important factors that indicate the good use of buildubility
concept in project performance?
How can the buildability, cost effectiveness be achieved?
How can the best relation between work teams and project performance be
achieved?
1.7 Hypothesis There is no statistical difference about the possibility of use buildability
influencing quality due to position of respondents.
There is no statistical difference between respondents due to their experience
about the possibility of using of buildability in influencing of quality.
1.8 Summary of research methodology Different research methodologies are discussed in detail, covering different
principles and classifications of research. The approaches and techniques chosen for
this particular research are presented. Primary techniques chosen are questionnaires,
expert structured interviews and case studies. To respond to the aims and objectives
of this research, the major works involved in the research methodology include:-
Phase 1: Literature review
The preliminary literature studies consists of the first gathering of academic
documents and study in order to determine the main issues related to the research
subject. From the preliminary literature review, some problems and concepts were
identified to generate problem statement and to map provisional scope of the
research.
4
Phase 2: Field survey
This stage has these steps:
In depth interviews with key experts in construction field in UNRWA Gaza
Field.
Structured questionnaire was distributed on design team and managers.
Case Study of three executed projects was used to verify the research results.
Phase 3: Data analysis and results
Detailed analysis is done and conclusion were reached, which was compared with the
findings of the questionnaire, structured interview with experts in construction field.
Quantitative data analysis methods, including descriptive analysis, reliability test,
person correlation, were conducted using Statistical Package for the Social Sciences
(SPSS).
1.9 Research scope and limitation The scope of this research covers buildability principle during the design process
only. The research was conducted mainly in UNRWA school buildings as case Study
in Gaza Strip; however, while conducting and establishing the research work, the
following constraints have been encountered:
This research will focus on the factors that causes buildability problem due to
designers.
This research is concerned with construction of school projects only and will
not take into account the other categories of engineering projects like civil
projects (tunnels, highways, bridges), or industrial projects (factories and
workshops), and utilities projects (sewage and water supply).
Only the UNRWA engineers in Gaza were involved in this study, therefore a
small size of population was considered.
1.10 Expected results The research is expected to provides the buildability concept influencing quality of
building design, identify the factors that causes buildability problem due to
designers, identify the factors that influencing the design process and provide the
project components weighting in UNRWA projects.
5
The research explores the responsibility of the managers, client, and design team to
achieve the high level of satisfaction. This outcome is likely to make facilities with
these goals more attractive and thereby increase the wider adoption of buildability
approach in early stage in design process.
The research outlines the following benefits:
Key factors that causes buildability problems.
Importance of buildability concept influencing of the design process.
Identify the factors that causes buildability problem due to designers.
Determine the project components weighting in UNRWA projects.
1.11 Research structure
Chapter One: Introduction
Describe the overview of this thesis, outlining the aims, objectives, scope, research
problem and approach to addressing the research goal.
Chapter Two: Literature review
The literature study is a review of all aspects concerning the defining and principle of
buildability, the benefit of improving buildabuility in the design process, guidelines
for good buildability, and factors that cause buildability problem.
Chapter Three: Research methodology
Different research methodologies are discussed in detail, covering different
principles and classifications of research. The approaches and techniques chosen for
this particular research are presented and their relevance motivated. Primary
techniques chosen are questionnaires, expert structured interviewed and case studies.
Chapter Four: Results and discussions for questionnaire
All the findings from the research interviews and questionnaire are summarized and
combined to formulate a final discussion.
6
Chapter Five: Interviews and case studies
Describes in detail a case study involving education project comprising UNRWA
school building in Gaza Strip to get in-depth data about the current difficulties
occurred during construction where buildings or facilities could not be built as
designed. Case studies aims to extract lessons and principles that can be applied in
the industry at large to improve buildability, which will improve the project
performance as well as the project schedule, and increasing the quality of building
during operation and maintenance stages.
Chapter Six: Conclusion and recommendations
Present the research conclusion and recommendations.
7
Chapter 2 LITREATUR REVIEW
2.1 Introduction The integration of design and construction are important to improve the quality of
project design during early stage of project. Buildability concept must be considered
from the initial preliminary design and discussed the requirement into the design by
the clients. Identification of the client’s needs and objectives will enable the designer
to use experienced construction knowledge from the outset to the completion of a
project. This chapter will describe briefly the definition, aspects, comparison
between constructability and buildability, principle of buildability, the benefit of
buildability, the key area of buildability and the designer team roles for quality of
design.
2.2 Defining buildability
The accepted definitions of buildability developed by the Construction Industry
Research and Information Association (CIRIA) in the UK, as: “ Buildability is the
extent to which the design of a building facilitates ease of construction, subject to the
overall requirements for the completed building (CIRIA, 1983). Other researchers
also derived their definitions based on their commitment to conceptual assumptions
and ways to studying buildability. A selected sample of these definitions is given as
follows:
Illingworth (1993) defined buildability as design and detailing which recognize the
assembly process in achieving the desired result safely and at least cost to the client.
Fisher and Rajan (1986) defined buildability as a measure of the ease or expediency
with which a facility can be constructed. Also, buildability is often described as
integrating construction knowledge, resources, technology and experience into the
engineering and design of a project
Moore (1996) modified Illingworth’s (1984) definition as a “design philosophy,
which recognizes and addresses the problems of the assembly process in achieving
8
the construction of the design product, both safely and without resort to
standardization or project level simplification.”
Ferguson (1989) defined buildability as the ability to construct a building efficiently,
economically and to an agreed or specified standard from its constituent materials,
components and sub-assemblies. Similarly, Williams (1982) defined buildability as
the most economic and efficient way of putting a building together.
Adams (1989) defined buildability as “the extent to which the design of a building
facilitates ease of construction, subject to the overall requirements for the completed
building.
Figure ( 2-1): The wider framework of buildability (CII, 1993)
2.3 Comparison between constructability and buildability Based on a comprehensive literature study term of constructability is widely used in
USA, while the buildability term is often used in UK.
Wong et al. (2007) concluded that constructability is concerned with the whole
process of project development to facilitate construction efficiency and achieve
9
project goals. By contrast, buildability deals mainly with construction efficiency seen
at the design stage, whereas constructability covers broader aspects spanning various
stages in building development. Both concepts indeed refer to the optimal use of
resources for construction or ease of construction. Despite the different interpretation
of buildability and constructability, there is consensus that the design stage is critical
for implementing buildability or constructability Wong et al. (2006). Constructability
therefore implies the integration of the contractors‟ knowle dge, not only from a
physical or technical perspective, but also the non-technical, into the design and
planning stages. These non-technical issues are often difficult to quantify and include
managerial, financial, legal or even psychological concerns during the project as a
whole ( Kuo, 2012). The Construction Industry Institute (CII) at the University of
Texas refers to constructability as “the optimum use of construction knowledge and
experience in planning, design, procurement, and field operations to achieve overall
project objectives “(CII, 1993). The CII at the University of South Australia defines
constructability as “a system for achieving optimum integration of construction
knowledge in the building process to achieve maximisation of project goals”.
2.4 The princple of buildability Cost, Schedule, Quality are the main indicators for project performance during the
project implementation. Therefore, the good project should be integration of good
buildability into good overall design. There are numerous studies have been
conducted in order to strive for better project performance through improving
buildability. Francis et al. (1999) found that better buildability could contribute to
early completion of projects; Jergeas and Put (2001) showed that buildable designs
would lead to saving in project costs and costs of change orders.
Different researchers have developed principle for buildability. Those principles that
may have relevance to the process of design for disassembly are shown in Table (2.1)
10
Table ( 2-1): Design for disassembly principality from buildability research (Crowther,
2002)
No. Principle Reference
1 Minimise the number of different types of components - this will
simplify the process of sorting on site and make the potential for
reprocess more attractive due to the larger quantities of same or
similar items.
Adams 1989,
Chen
1994, Hon 1988
2 Use an open building system where parts of the building are more
freely interchangeable and less unique to one application - this will
allow alterations in the building layout through relocation of
component without significant modification.
CIRIA 1983,
Hon et el.
1988
3 Use modular design - use components and pre-assembled
subassemblies that are compatible with other systems both
dimensionally and functionally.
Adams 1989,
Chen
1994, CIRIA
1983,
Hon et al. 1988,
llingworth
1993
4 Use assembly technologies that are compatible with standard building
practice - specialist technologies will make disassembly difficult to
perform and may require specialist labour and equipment that makes
the option of reuse more difficult.
Adams 1989,
CIRIA
1983, Miller
1990
5 Provide access to all parts of the building and all components – ease
of access will allow ease of disassembly, if possible allow for
components to be recovered from within the building without the use
of specialist plant equipment.
Adams 1989,
Hon et al.
1988
6 Use components that are sized to suit the intended means of handling
– allow for various possible handling options at all stages of
assembly, disassembly, transport, reprocessing, and re-assembly.
Adams 1989
7 Provide a means of handling components during disassembly –
handling during disassembly may require points of connection for
lifting equipment or temporary supporting devices.
Adams 1989,
Illingworth 1993
11
Table (2-1): Continue
8 Provide realistic tolerances to allow for movement during
disassembly – the disassembly process may require greater tolerances
than the manufacture process or the initial assembly process.
Adams 1989,
CIRIA
1983, Hon et al.
1988,
Illingworth
1993,
Miller 1990
9 Design joints and connectors to withstand repeated use – to minimize
damage and deformation of components and materials during
repeated assembly and disassembly procedures.
CIRIA 1983
10 Allow for parallel disassembly rather than sequential disassembly -
so that components or materials can be removed without disrupting
other components or materials, where this is not possible make the
most reusable or ‘valuable’ parts of the building most accessible, to
allow for maximum recovery of those components and materials
that is most likely to be reused.
CIRIA 1983,
Miller
1990
11 Use prefabricated subassemblies and a system of mass production -
to reduce site work and allow greater control over component quality
and conformity.
CIRIA 1983,
Hon et al.
1988
12 Provide spare parts and on-site storage for them - particularly for
custom designed parts, both to replace broken or damaged
components and to facilitate minor alterations to the building design.
CIRIA 1983
13 Sustain all information on the building manufacture and assembly
process – measures should be taken to ensure the preservation of
information such as ‘as built drawing’, information about
disassembly process, material and component life expectancy, and
maintenance requirements.
Adams1989,
CIRIA 1983
2.5 The buildable design appraisal system (BDAS) The Buildable Design Appraisal System (BDAS) was developed by the building and
Construction authority. This system used to measure the potential impact of a
building design on the usage of site labour. The appraisal system results in a
‘Buildable Design Score’ of the building design. A design with a higher buildable
12
design score will result in more efficient labour usage in construction and therefore
higher site labour productivity (BCA, 2011).
The objective of (BDAS) is to result in the wider use of buildable design. It is not the
intention to adopt buildability at the expense of good architectural design. The need
for more varieties and architectural features to satisfy clients’ needs is recognised.
The designer should first consider external factors such as soil condition, access and
storage at the site, availability of resources, skills and technology, sequence of
operations etc., to determine the most appropriate building system to be used.
Therefore the designer should apply the followings three “S” principles of
Standardization, Simplicity and Single integrated elements to achieve a buildable
design (BCA, 2011).
1. Standardization refers to the repetition of grids, sizes of components and
connection details. A repeated grid layout, for example, will facilitate faster
construction whether formwork or precast components are used. Similarly,
columns or external claddings of repeated sizes will reduce the number of
mold changes whether on-site or in the factory.
2. Simplicity means uncomplicated building construction systems and
installation details. A flat plate system, for example, eases formwork
construction as well as reinforcement work considerably. Use of precast
components reduces many trade operations on site and should improve site
productivity provided the standardization principles are observed.
3. Single integrated elements are those that combine related components
together into a single element that may be prefabricated in the factory and
installed on site.
2.6 The benefit of buildability
The benefit of buildability can occur at all stages of project although, the Pareto
Principle (known as the 80/20 rule, is a theory maintaining that 80 percent of the
output from a given situation or system is determined by 20 percent of the
input), dictates that, the earlier in the process that buildability is implemented, the
greater will be the potential of time and cost savings and quality improvements. Lam,
Wong & Chan (2006) claimed that the implementation of buildability management
13
can lead to significance quantifiable improvements in project performance in terms
of time, cost and quality.
The buildability implementation in the construction industrial that give the negative
or positive indicators of the project performance. Reducing the negative factors of
the buildability aspects such as expanding the repetition of similar specifications
used in the building elements will influence the positive result, such as higher
productivity; improve the utilization of resources, etc. If the negative factors of the
buildability aspects are left unchallenged i.e. building elements vary in shape and
specification, it would reduce, or influence the buildability level of the project.
Based on the researcher experience with common in the lessons learned, the project
could be delayed by variation orders which would normally be issued to rectify
design problems. For the designers, they could possibly lose the opportunity to take a
new project as they are occupied with extra redesign works caused by impractical
designs found during construction in the current project.
It is recommend to creating a maintainability alert for both project managers and
maintainability guarantors as early as possible in the projects. They insist on
consulting all post-occupancy stakeholders during this process. As an approach,
maintenance factors should be inserted into buildability considerations in order to
facilitate a better maintainability process (Saghatforoush et al. 2011).
Figure (2.2) shows the that it needs more efforts during planning and design phases,
but causes lower total cost lastly.
Figure ( 2-2): Optimum design input (adapted from Saghatforoush et al. 2011)
14
Furthermore, depending on the nature of the variation and redesign requirements for
the running project, it could also affect the designers’ reputation and client
confidence. In short bad buildability leads to increased cost, delays the project, and
reduces benefits to every party in the project (Coombs, 1983). On the other hand, the
consequences of good buildability projects are also varied, for example, the clients
could have their building project completed within time and budget, without
additional major costs to variation, minimum disruption, efficient operation on site,
and aesthetically and functionally pleasant. The designers could have less design
problems on site during construction as well as when commissioning since their
designs will have been evaluated based on the operational requirements on site.
The designer’s reputations also increase with a good deliverable designed project
(Adam, 1989; Griffith, 1984).
If buildability aspects are considered by the team at the early stage in design, the type
of construction methods and its construction activities can be accurately be allocated
in advance. Thus, the project can be efficiently constructed as accurate construction
project planning and its predefined construction methods can be developed. The
expected project duration also might be reduced, since less variation orders would be
issued and interruptions caused by impractical design details are almost eliminated.
The construction of the project would be able to run smoothly since less conflict
between parties over design solution would be encountered, etc. Figures (2.3) below
shows the stages for a project life cycle and indicate how progress made on each
stage could lead to decreasing influence from designer and increasing in the project
expenditure.
15
Figure ( 2-3): Construction project phases (Thabet, 2006)
2.7 The key areas of buildability The aim of buildability is to improve the efficiency of the overall building process by
developing construction sensitive designs (Hassan, 1997). The expected results from
implementing buildability are efficient and effective construction of a building, with
an economical project cost and at agreed quality specified by the clients. Although
most researchers and organisations involve in buildability agree on the purpose of
buildability, which is to ease the construction activities without effecting the quality
and performance required, they differ in the aspects of buildability and at which
stages of the project life cycle it is essential that buildability is implemented in the
project (Hassan, 1997).
2.8 Guidelines for good buildability From the range of buildability definitions given earlier in this research, the
implementation of buildability requires all parties involved in the design and
construction to work together to secure good buildability, various guidelines have
been produced to be observed and implemented for buildability of the project. CII
Constructability Task Force described seven guidelines for accomplishing
buildability in project development (CIRIA, 1983);
16
1. Construction-driven planning and programming, the objective can be
fulfilled by developing a general construction programme before design and
procurement schedules are developed. The programme is characterised by
creating a schedule from the required date the project has to be completed and
working backward to establish the duration of various tasks, i.e. start-up,
checkout phase, the date where the structure has to be ready for services
equipment, etc. The construction programme developed would be able to
indicate when the issuance of drawings, specifications and delivery of
materials should be placed. After the drawings and specifications have been
completed, further detailed and finalised schedules would be developed for
the construction works in an interactive manner.
2. Design simplification, complex detailing which require difficult construction
methods, could take longer construction time and costly resources and
therefore should be avoided. Design should enable efficient construction.
Although safety, operability, maintainability and aesthetics are the usual
project objectives which frequently transcend buildability, the design layout
and design details may often be modified to enhance buildability without
sacrificing the project objectives.
3. Standardisation and repetition of design elements, this would reduce the
learning curve and increase construction activity efficiency. Savings could be
realised when the number of variations of components is kept to a minimum
as it could simplify material procurement and materials management from
fewer differing materials.
4. Specification development for construction efficiency, designers are
recommended to use specifications which can provide smooth and efficient
construction methods. The appropriate use of basis design specifications and
avoidance of misapplied materials specifications could simplify the
construction process.
5. Modular/preassembly designs should be developed to facilitate
prefabrication, transportation and installation. The benefit of
modular/preassembly designs include improved task productivity, parallel
17
sequencing of activity, increased safety, improved quality control and a
reduced need for scaffolding.
6. Design should allow for accessibility of labor, materials and plant,
accessibility of the resources to site is a major requirement for effective and
efficient construction. Projects would be delayed or incur high construction
cost if accessibility was not taken into consideration when designing the
project.
7. Design should facilitate construction under adverse weather conditions
Similar to the above objective but expressed in different words, Construction
Industry Research and Information Association (CIRIA, 1983), identify seven
guidelines for both designer and contractor to follow in order to obtain good
buildability. The guidelines proposed that:
1. A thorough investigation of the site conditions should be made and worked
into the completed design before any documentation is started.
2. The layout and phased completion of sections of the building should
recognise the requirements of site access, materials handling and the
construction sequence.
3. The method of construction should encourage the most effective sequence
and should recognise the benefits of completing a "dry envelope" early on in
the contract.
4. Designers should plan simplicity of assembly during the fitting out of the
building and for a logical and ordered sequence of trades.
5. Maximum repetition and standardization of components and building
elements should be adopted.
6. Building designs should be prepared with achievable and appropriate
tolerances.
7. Robust and suitable materials to allow for site conditions and the capability
of being protected should be specified.
18
2.9 Factors affecting buildability Wong et al. (2004) identified 16 groups of factors affecting buildability. They found
that improvement towards buildability can be realised by persistently optimizing the
nature of these factors during design, these factors was summariesed in Table (2.2) as
followings;
Table ( 2-2) Factors affecting buildability (Wong et al. 2004)
1) Site-specific Factor
Thorough site/ground investigation (e.g., bore holes, topography survey, cable
detection, survey on adjacent buildings).
2) Site Layout, Access and Environment
• Allowing sufficient working space for labour and plant.
• Enabling efficient site layout, storage and site access.
• Allowing less wet trades on site.
• Causing less environmental nuisance (e.g., noise, vibration, waste water, chemical
waste and dust) to surroundings.
• Allowing for early enclosures from weather.
• Allowing for construction traffic on permanent structure early after erection (e.g.,
left-in steel decking on structural steel).
3) Below Ground
• Designing for minimum construction time below ground.
• Designing for safe construction below ground.
• Considering effects of below ground work on surrounding buildings, e.g.,
destabilizing foundations.
4) Co-ordination and Rationalisation of Design Information
• Co-ordinating drawings and specifications.
• Updating specifications and removing ambiguities/misunderstandings.
• Dimensional co-ordination.
• Providing/facilitating combined services drawings.
• Showing accurate positions for pipe sleeves and penetrations
5) Detailing
• Specifying tolerances for as many items as possible.
• Co-ordinating tolerances specifications for interfacing items (e.g., window frame
vis-à-vis window opening).
19
Table (2-2): Continue
• Designing to aid visualisation of finished work.
• Referring to typical/standard details for repetitive items.
Using blow up details to examine possible clashes in the design, e.g., building services
clashing with reinforcements
6) Flexibility
• Designing for interchangeability (e.g. left/right orientation of fittings, such as
cabinets, kitchen sinks) and sub-assemblies.
7) Tools, Plant and Equipment
• Designing for optimum use of plant and equipment.
• Designing with knowledge of plant and equipment capacities.
• Designing for temporary plant and equipment anchorages in permanent structure.
8) Materials, Fittings, Products and Sub-assemblies
• Designing for locally available materials/fittings/products/sub-assemblies (including
imports).
• When imported materials/fittings/products/sub W assemblies are specified, consider
supply conditions (e.g., checking lead-times and foreseeable shortages).
• Specifying robust and suitable materials/components or giving directions for
protecting fragile items (e.g., precast stairs).
• Designing to facilitate care and protection of completed works by contractors.
9) Use of Resources
• Allowing use of plant and equipment available locally.
• Allowing use of know-how and labour skills available locally.
• Allowing economical use of labour and plant (e.g., balancing between labour and
plant use to reduce overall cost).
• Avoiding as far as possible multiple handling and visits by different trades.
10) Material Systems
• Allowing use of wide range of materials to fulfill required performance.
• Giving rise to lower cutting wastages (e.g., tiles, rebars).
11) Installation
• Allowing easy connection/interfacing between components.
• Allowing adaptation (e.g., piping around obstacles instead of penetrations) by
contractor on site without extensive re-work.
• Specified tolerances capable of being achieved.
20
Table (2-2): Continue
• Allowing easy installation without complicated fixings.
• Allowing flexibility in erection/trade sequences (e.g. G/F slab laid after all upper
floors).
• Allowing for early removal of temporary support to leave clear working space
12) Standardisation
• Uncomplicated geometry, layout and shape.
• Allowing modular layout of components.
• Allowing a high degree of standardisation and repetition.
• Allowing use of standard details with lots of repetitions, thereby facilitating learning
curve of workers to be built up fast.
13) Prefabrication
• Allowing prefabrication off site.
• Enabling the adoption of single integrated elements (e.g., whole toilet completed
with sanitary ware, piping & finishes) at the discretion of contractor.
• Optimising the mix of offsite work (e.g., prefabrication, precasting and pre-
assembly) and onsite work (e.g., final leveling and fixing).
14) Innovations
• Designing to allow for innovative construction techniques to be proposed by
contractor.
• Suggesting non-obligatory construction methods for contractor to consider.
15) Weather
• Considering possible timing to avoid carrying out structural work, external finishes,
etc., during rainy/typhoon season.
16) Safety
• Allowing safe sequence of trades (e.g., heavy M&E plant hoisted into position
before building is fully enclosed).
• Sizes and weights of materials and components are safe for workers to handle using
commonly available plant.
21
2.10 Factors cause buildability problems The important of focusing on the design stage for improving buildability has been
highlighted in most studies and confirmed the positive relation between improved
buildability and saving in project costs and time, as well as better safety and quality
performance (Lam et al.2006).
Aina & Wahab (2011) has identified that the occurrence of buildability problem is
increasing in proportional to the period of time. Hence, the occurrence is increasing
in ascending order with period of time (the highest occurrence of buildability
problem occurred at period of one year and descending from six months, three
months one month and lower at one week period of time. The very high causes of
buildability problem from the comparison of the result of three different parties of
respondent are:
complexity of the project, faulty defective of working drawings, resistance of client
to buildability programmes, budgetary limitation, non-standardization, incomplete
specification, separate design and construction operation, lack of awareness of
construction technology, lack of awareness of buildability concept, poor
communication skill .
Other causes such as no document of lesson learnt, adversarial relationship between
designer and contractor, construction input is request too late to be of any value,
discontinuity of key project personnel are between high cause and average causes of
buildability problem.
Wong et al. (2006) has listed the below main factors that causes the buildability
problem due to designers
1. Lack of knowledge.
2. Experience in construction.
3. Designing without input or the involvement of contractors.
4. Projects with increasingly demanding coordination.
5. Requirements (such as sophisticated building services and building
automation systems).
6. An ignorance of contractors’ proposed changes, a lack of communication
between the parties involved.
22
7. Time taken for a plan to be approved by the government means that
consultants would be reluctant to change their basic designs for better
buildability at the contractors’ advice.
8. The tight timeframe for designing and tendering has also resulted in designers
and tenderers not having enough time to prepare careful designs and pricing,
respectively. The highly fragmented roles and specialisation of various
consultants in a project team further complicate the responsibility for
effecting buildability improvements
Mydin et al. (2011) identified 19 buildability attributes in building design phase for
Malaysian construction industry. The main finding in this studded and result of
survey, the attribute provide clear and complete design information, is considered as
the most important. While less work below ground, is considered as the least
important attribute. The client, consultant and contractor share the same opinion
regarding the most important and the least important attributes. The study has
successfully assessed the importance level of buildability attributes among Malaysian
construction practitioner.
2.11 Improving buildability at the design process Wong F. et al. (2004) said that , the design process involves human interaction and
the design outcome is a trade-off among many conflicting needs, encompassing the
interpretations, perceptions and prejudices of the participants (Gray and Hughes
2001). However, a building design is sometimes only regarded as an art work (Gray
and Hughes 2001), with the designers paying little attention to tackle difficulties that
would confront constructors during construction. Constructors have virtually no
input into the design (Bower, 2003). In view of the inherent problems that resulted
from late, incomplete or uncoordinated design information and design that were
difficult to build. Coles (1990) carried out a survey to identify the inadequacy of
design process management. Results showed that the sources of problems are:-
1. Poor briefing and communication.
2. Inadequacies in the technical knowledge of designers.
3. A lack of confidence in pre-planning for design works.
23
The above problems are detrimental to the whole project teams. As such, there is an
increasing awareness of the need to improve management of the design process in
the construction industry with focus being put on the design deliverables. In
particular, attention has been given to improving buildability of designs. For
example, carrying out design-phase scheduling and reviewing of in-house design-
phase buildability has been proposed by Glavinich (1995).
A computer-aided methodology has been put forward to ease the incompatibility
with other components or errors in designs as well as potential difficulties during
construction, resulting from design change of a building component (Mokhtar et al.
2000).
A buildability checklist has also been developed for designers by Gray and Hughes
(2001). They believed that as the complexity of construction operations is difficult to
determine without extensive site experience, a design should be as simple to
construct as possible. All these echo the need for tools that allow undertaking design
management that accounts for and addresses the need for changing roles within the
team (Wong et al. 2004)
Figure (2.4) indicate that project owners are still suffering from costs of reworks
during operation and maintenance of their projects, whilst these two phases include
around 50% to 80% of the total life cycle costs, were it is equal to even more than
design and construction stage of project lifecycle.
Figure ( 2-4): Life Cycle costing profile (adapted from Saghatforoush et. al. 2011)
24
2.12 Building performance criteria In order to improve building performance it is of prime importance to establish the
criteria to be used for evaluating building performance. This will help design firms to
utilize the construction knowledge and experience of project participants, contractors
in particular, to achieve these criteria as an approach for improving building
performance.
Building performance criteria could be carried out at three levels. Health, safety and
security performance, functional, efficiency and work flow performance;
psychological, social, cultural and aesthetic performance (Preiser and Vischer, 2005).
2.13 Benefits of measuring building performance Although measuring building performance helps understanding current building
performance and end-users requirements, it is an important tool for managing and
planning for new facilities. The benefits of measuring building performance range
from short term to long term (Othman, 2011).
1) At the short-term
Measuring building performance allows clients and facility management team to
have a better understanding of the functionality and performance of their buildings
compared with the stated criteria during design. In addition, active user participation
in the evaluation process plays an important role in defining and considering their
needs and requirements in the design of new buildings (Othman, 2011).
2) At the medium-term
The data collected during the assessment of building performance can be used as a
source of knowledge for planning new buildings of similar type. Designers equipped
with user feedback are helped to design future buildings that more closely meet the
needs of the users (Othman, 2011).
3) At the long term
Measuring building performance helps establishing databases, generates planning
and design criteria for specific building types and enables designers to consider
documented past experience. This is important to avoid repeating past errors and
25
recognise past success. The accumulated information plays a pivotal role in
improving the quality of future buildings and services to the client and users.
Assessment results may also improve design practice by making designers aware that
their buildings may be subject of scrutiny. Thus design of future buildings may lead
to better value for money to clients and society. This concern not only issues of
functionality, but overall sustainability, energy efficiency and environmental impact
(Othman, 2011).
2.14 The RIBA plan of work In 1964 the Royal Institute of British Architects (RIBA) published the RIBA
Handbook in which was published a model procedure for methodical design process,
termed the RIBA plan of Work. Subsequently, the plan of work was revised in 2000
and then updated in 2007 to cope with the ever-changing business environment, meet
clients and users’ expectations as well as technology enhancement. The process is
typically broken down into 5 main phases namely, preparation, design, pre-
construction, construction and use. Detailed description of the activities to be carried
out in each phase is mentioned in Table (2.3) (Othman, 2011).
Table ( 2-3): The RIBA plan work (Othman, 2011) Preparation
A) Appraisal
• Identification of client’s needs and objective, business case and of
possible constraints on development.
• Preparation of feasibility studies to enable the client to decide
whether to proceed.
(B) Design brief
• Development of initial statement of requirements into the design
brief by or on behalf of the client confirming key requirements
and constraints.
• Identification of procurement method, procedures, organisational
structure and range of consultants and others to be engaged for the
project.
Design C) Concept
• Implementation of design brief and preparation of additional data.
• Preparation of concept design including outline proposals for
26
Table (2-3): Continue
• Structural and building services systems outline specifications and
preliminary cost plan.
Review of procurement route
(D) Design development
• Development of concept design to include structural and building
services systems, updated outline specifications and cost plan.
• Completion of project brief.
• Application for detailed planning approval.
(E) Technical design
Preparation of Technical design(s) and specifications sufficient for co-
ordination of all components and elements of the project. And information
for statutory standards and construction safety
Pre-
Construction
(F) Production information
• F1 Preparation of detailed information for construction.
• Application for statutory approvals.
• F2 Preparation of further information for construction required
under the building contract. Review of information provided by
specialists.
(G) Tender documentation
• Preparation and collation of tender documentation in sufficient
detail to enable a tender or tenders to be obtained for the
construction of the Project.
(H) Tender action
• Identification and evaluation of potential contractors and/or
specialists for the construction of the project.
• Obtaining and appraising tenders and submission of
recommendations to the Client.
Construction (J) Mobilisation
Letting the building contract, appointing the Contractor.
Issuing of production information to the Contractor.
Arranging site handover to the Contractor.
(K) To practical completion
• Administration of the building contract up to and including
27
Table (2-3): Continue
• Practical completion.
Provision to the Contractor of further information as and when reasonably
required
Review of information provided by contractors and specialists.
Use (L) Post practical completion
• L1 Administration of the building contract after practical
completion and making final inspections.
• L2 Assisting building user during initial occupation period.
• L3 Review of project performance in use.
2.15 Variability factors in the management of design process During the design process, the arhitect hase infouleuenct in the quality of design,
which will can affect whole project lifecycle. By project progressing, the influence of
designer reduces while the effect of expenditure increases. Thus, it is recommended
to apply buildability at earlier design stages of project in Table (2-4).
(Rounce, 1998) hase found that several variability factors in the management process
which can affect the saving and profitability of project. The following comments
were identified base on his solely personal experience in design management.
1. Variability in managerial skills of team leaders.
2. Variability in the ways jobs are organized.
3. Variability in numbers of drawings required for project.
4. Variability in scale of drawings and consequent level of design detail shown.
5. Variability in technical performance of team members.
Table (2-4): Design management recommendation (Rounce, 1998)
Tender stage Reducing
waste
Improving
efficiency
Reducing
risk
• Produce architects projected drawing list
• Produce architect design programmes based on
projected drawings list
• Define other designers responsibility at details of
Y
Y
Y
Y
Y
Y
Y
Y
Y
28
Table (2-4):Continue
• start project
• Define reasons for revisions reasons and locations
on drawings
Y Y
• Carry out pilot studies on need for drawing
revisions
• Develop standard checklists-completeness of
information on drawings
• Consider use of pilot design quality plans on some
new project Monitor effectiveness
• Confirm drawing design information requirement
from others on drawings
• Carry out fee cash flow risk analysis at start of
new projects
• Develop procedures for fee recovery from
repeated planning applications
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Contract stage Reducing
waste
Improving
efficiency
Reducing
risk
• Ensure competence of design warranties for
sub-contractors carrying out design
• Obtain sub-contractors design programmes and
projected lists from their sub-contractors with
design responsibilities
• Produce programmes for design information
for PC and provisional sums
• Produce programmes for Building Regulations
Approval
• Ensure completeness of information on main
contractors programmes
• Use standard working details where possible
• Collect project feedback records to identify
successes and failures and reasons
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
29
2.16 The designer team roles for quality of design A design team is a group of professionals that responsible to take the design
decisions that can affect how the building is to be built and determine the
management system during the implementation process. Therefore the success of any
project should be influenced by communication and understanding within the design
team throughout the design process. Under the traditional design –bid build
procurement system, designs are usually carried out by architects, the design process
was realized that 80% of the construction cost was taken as soon as the design sketch
was, mad any a mistake or omission that was not discovered or settled earlier could
lead to serious demand and rework when the construction starts. In addition, the most
cost for a mistake in design would cost more than a mistake in construction (James et
al. 1991).
a) Architect: takes the lead responsibility for developing the owner’s program,
first into generic or conceptual design, then more details, and finally into for
complete set of drawings and other documents sufficient to have the project
assembled in the field relationship (Bennett, 2003).
b) Engineer: takes charge of planning and design phase, coordinating the
various parties and their activates, the engineer may be involved with utilities
studies, structural, heating, ventilating and air conditioning system, data
communications system, roadway layout, pavement design, mechanical,
electrical, earthwork and foundation systems (Bennett, 2003).
c) Quantity surveyor: as cost advisor, manages the cost planning exercise to
ensure the design meets the client’s budget. The quantity surveyor is
conducted at various points during the planning and design phase, not just
during construction document. In some planning this work is reformed in
conjunction with that of the cost estimator. As more design is developed, the
cost estimator provides more cost details. The degree of accuracy improves as
more detail is developed, at early stage of design the cost estimate is probably
accurate to within +-30%. When the design process the cost estimate is
30
probably accurate to within +-20%, when final construction documents are
ready for tender process, as estimate of accuracy of +-10% can be expected
(Bennett, 2003).
d) Geotechnical specialist: Soil and foundation work is integral to most
projects, often the specialist will be involved at early in the planning and
design phase, the geotechnical specialist might be engaged to advise on
dealing with earthquake susceptibility, soft sediments, alterative foundation
solution, unstable slope, footing potential, and contribute studies of
environmental impacts (Bennett, 2003) .
e) Land surveyor: a site investigation is much needed after one has been
selected, this works included the right boundaries, land contours and slopes
and location of existing and future improvement. A pipeline or highway
project can involve much preliminary route layout as various alternative
routes are investigated. Various kinds of maps and geographic information
system can proceed for use in project design and planning.
2.17 The design quality consideration Design quality is a critical success factor for projects and requires a balance to be
struck between functionality, impact, build quality and value for money. Clients have
responsibility for commissioning buildings of good design quality at an affordable
and reasonable cost (Finance, 2009).
Design quality can be uniquely defined for each facility in any project type. There
are some general considerations that apply to most projects:
Efficient use of space;
Positive environmental impact;
Secure and safe facilities;
Energy efficient buildings;
Universal accessibility; and
Future-proof design.
31
2.17.1 The steps to achieve the design quality
Rounce (1998) suggested that,quality in construction is meeting agreed requrements
or conformance to requirements and it is referred to in quality management terms and
standards of details and finish, therfore everyone involved in building project wants
to achieve quality of building.
Figure (2-4) shows the number of steps that a client can take to achieve design
quality in a project; these include the following (Finance, 2009):
1. Review designs regularly to ensure that they satisfy the needs expressed in
the Definitive Project Brief.
2. Insist on the submission of design information that can be readily understood.
3. Check designs regularly to ensure that the requirements of the Definitive
Project Brief are met in the following areas:
Schedules of areas, room data sheets, specifications and whole-life-value-for-
money (for building projects); and
Capacity, level of service and whole-life value-for-money (for civil
engineering projects).
4. Check that the designs are consistent with the intended business objectives of
the facility.
5. Sign off on design should occur only when all elements of the design are
agreed.
Figure ( 2-4): Steps that a client can take to achieve design quality in a project
32
2.17.2 The benefits of design quality
Contributing to a construction process that is efficient and safe, and that
creates a built environment that is non-threatening;
Making a positive addition to the project’s location, environment and
community by creating an attractive and healthy environment for users;
Achieving universal accessibility targets;
Adding value and reducing whole life costs by producing facilities that are
easy and cost effective to manage, clean and maintain;
Creating a flexible, durable, sustainable and ecologically sound environment
for the community;
Minimising pollution, waste of materials and use of energy both in
construction and in use.
2.18 Productivity concept in construction industry In simple terms, productivity can be expressed as the relationship between the output
generated from a system and the input used to create output. Inputs generally refer to
labour, capital, energy and materials which are brought into a system. These
resources are transformed into outputs, i.e. goods and services (Lim, 1996).
There are more basic forms of productivity, namely:
Total productivity (sometimes known as total factor productivity); and partial
productivity (sometimes called partial factor productivity).
Total productivity is the ratio of total output to all input factors. Partial
productivity is the ratio of total output to one class of input, e.g. labour
productivity is a partial productivity measure.
Total productivity=Total Output/Total Input
Partial productivity-Total Output/Partial Input
Lapour productivity=Lapur(trade) Output/Lapour(trade) Output
33
2.19 Quality function deployment and buildable design Quality function deployment (QFD) is an integrated decision-making methodology
that can assure and improve the alignment of elements of design and construction
processes with the overall requirements of a construction project.
The basic rationale of QFD is to systematically take the customers’ desires down to
the level of detailed operations ( Yanga, et al. 2003).
To achieve a buildable design, the three dimensions of customers and their
satisfaction need to be analyzed and evaluated, respectively, under the overall
requirements for the completed building Figure (2.5).
Based on this enlarged concept, customers and their requirements of buildable
designs can be divided into three dimensions:
The client is the customer who employs the designers to develop construction
documents that the contractors will use to satisfy the client. The client who is
also a participant and promoter of buildable design will state his/her
requirements at the outset of the design and expect a high quality service to
satisfy his/her requirements and gain real value for money.
The designers are the customers who receive the design-relevant information
and requirements from the client as well as the design-relevant construction
inputs from the construction professionals that should be involved in creating
buildable designs. They need to satisfy their personal motivations through the
drawings that are represented as the series of technical and physical
characteristics of elements of buildings (e.g. roof, wall and finishes, and
superstructures).
The contractors are the customers who utilize the designers’ products, the
drawings, to construct the facility. The knowledgeable and experienced
construction personnel are also the contributors of buildable designs. They
contribute their knowledge and expertise to the various buildability issues,
e.g., the alternative construction methods and the site issues, and expect to
optimize the design for ease of construction and make profits.
34
.
Figure ( 2-5): Customer and their requirements of buildable design ( Yanga et al. 2003)
2.20 Chapter summary This chapter reviews literature related of buildability approach in design process. It
also reviews the definition, principle, and the key areas of buildability. Guidelines for
good buildability have been also discussed. The emphasis of this study is to assess
buildability concept in design process to achieve the quality of building performance.
The impact of the project performance during lifecycle of the project was discussed.
It has been also highlighted the benefits of quality function deployment and buildable
design and the benefit of the major concepts that give maximum opportunity to
deliver a high quality project on time and at the agreed cost.
35
Chapter 3 RESEARCH METHODOLOGY
3.1 Introduction In this chapter, the research methodology is discussed in full. Some classifications
and principles of research are covered, leading up to the description of different
research techniques and their conditions, and finally the research techniques chosen
for this specific research are presented, and their relevance motivated. Primary
techniques chosen are questionnaires, expert structured interviewed and case studies.
It contains information about research style, research design, sampling (include
population and sample size), data collection, data measurement, and data analysis.
3.2 Research techniques Defining the appropriate research technique to be implemented deals with four key
issues (Yin, 1993), what questions to study, what data is relevant; what data to
collect, and how to analyses the results. Technique selection depends upon three
conditions: the type of research question; the control of the investigator over
behavioral events; the focus on contemporary phenomenon.
The structured interview is also identified as an important technique and can form
part of the case study in acquiring in-depth knowledge through a dynamic interaction
with field personnel and experts. The case study approach is considered appropriate
as it allows an empirical enquiry to investigate contemporary phenomena within real
life criteria and can act as an additional filter of validation with regards to the
research argument. Therefore in this research, the “mixed- method” approach was
adopted. Collecting data using multitude methods and from multiple sources lend
rigor to research and can potentially reduce potential bias associated with some data
collection methods (Sekaran and Buojie, 2009). Figure (3.1) outlined the
methodology flowchart used for the research. The following investigation techniques
are appropriate and thus employed:
1) Literature review
2) Questionnaire
3) Structured interview
4) Case study
In the sub-sections below, each technique is discussed – first generally and then with
specific reference to this research.
36
3.2.1 Literature review
The literature review forms part of the methodology in this research. The literature
study only serves to establish the fundamentals of the concepts explored in the
research. The relevant existing research done in similar fields are studied. Major
themes and important concepts are identified and the relationships between them are
derived. This partially enabled the formulation of the problem statement and thus
contributes to narrowing down the methodologies feasible for actual data collection.
However, more details on this were discussed under Chapter 2 literature review.
3.2.2 Questionnaire The questionnaire is by far the most widely used research method, because it can be
very specifically designed to focus on a certain purpose in different circumstances. It
is decided for the questionnaire to be used as the primary research technique for data
collection. It is chosen as the preferred technique due to the nature of this research,
which requires the extraction of a wide variety of data and knowledge from
personnel in the industry. The research objectives require the acquisition of data from
a wide range of respondents. Buildability is viewed differently by different people
representing a number of different backgrounds. The knowledge management
initiatives are also subjected to contrasting perspectives by different personnel.
Qualitative research methods are considered ideally suited to study this concept as it
enables the extraction of perceptions among industry personnel. Quantitative
methods do play a role in this research and are considered valuable in the processing
of qualitative data obtained in the research process. The questionnaire allows the
following to be achieved:
Assured anonymity for the respondents;
Distribution to a diverse selection of geographically separate respondents;
Rapid distribution and collection of data;
Small amount of time required for respondents. Involvement quick
completion;
The inclusion of open-ended and closed questions consistent qualitative
response without potential consideration of different distribution platforms
and their respective advantages and disadvantages.
37
3.2.3 Structured interview
The interview allows a dynamic exchange of knowledge between researcher and
respondent. Usually personal interviews are conducted with or after a questionnaire
session, where the respondent’s answers can be explained in more details.
3.2.4 Case study
Numerous case studies have been found in past construction engineering
management (CEM) research, which employ both quantitative and qualitative
methods. In some cases personal observation or participation by the researcher was
fulfilled. Other cases were based on information from interviews with project
participants or through the collection of documents in the archives or records of data
captured during the case study project. The case studies have been done in two
schools and one health center in UNRWA. These types of projects are considered as
the major project. Where each project have multi similar and repeated items that
affect on design quality at an affordable and reasonable cost and time schedule. The
potential lessons learned by the case studies, guidelines to buildability approach
during design of the project, details of the case study are given under the chapter
dedicated to the case study later in the thesis (Chapter 5).
38
Figure ( 3-1): Methodology flow chart
Phase-1
Preliminary study and topic selection
Formulating the problem statement
Refine the aim and objectives of research
Phase-2
Questionnaire design
Data analysis and discussion
Literature review
Structured interview design
Pilot study Validity test
Reliability test
Data Collection
Article Journal
Research papers
Published
Website Discussion with other researcher
Meeting and discussion with
experts
Phase-3
Case studies
Conclusion and recommendations
39
3.3 Questionnaire design The questionnaire was designed in the English language and attached in appendix
(1). Unnecessary personal data, complex and duplicated questions were avoided. The
questionnaire was provided with a covering letter which explained the purpose of the
study, the way of responding, the aim of the research and the security of the
information in order to encourage high response. The form of closed questions are
easy to ask and quick to answer, they require no writing by either respondent or
interviewer, make tabulation and analysis easier, and minimize potential errors due to
differences in the way questions are asked. It always requires short responses
(Naoum, 2007).
The questionnaire design was composed of six parts to accomplish the aim of this
research, as follows:
General information
It is necessary that general information be defined in order to understand many
variables of the studied research factors. It includes information about the position,
education, experience of respondents, and question to understand the level of
knowledge in buildability during design process.
Part I: Buildability concept influencing quality of building design
This part investigated the design process which influencing the success of quality of
design. Ten factors are selected in order to investigate its influence on the success of
quality of design.
Part II: Factors that causes buildability problem due to designers
This part investigated the design process which influencing the success of quality of
building performance. Nineteen factors are selected in order to investigate its
influence on the success of quality of building performance based on the
respondent’s opinions and experiences.
40
Part III: Factors that influencing the design process
This part investigated the factors which influencing the quality design process.
Twenty factors were selected based on the respondent’s opinions and experiences.
Part IV: The project component weighting
This part investigated the project weighting as percentage which can affect on the
project quality and improvement. Seven project components were selected based on
the literature review and structured interviews with the expert engineers.
Part V: Facades finishing material affecting buildability of building design
This part investigated the effects of finishes on buildability of building design. Two
sub sections are defined through the research. Each section includes a number of sub-
elements to study its influence on the buildability of building design.
3.4 Research period The study started on November 2013 after the proposal was approved. The literature
review was completed at the end of January 2014. The validity test, pilot study,
questionnaire distribution and collection were completed in the beginning of March
2014. The analysis, discussion, conclusions and recommendations were completed in
the end of September 2014.
3.5 Research location The research was carried out in UNRWA Gaza Field Engineering Department, which
consists of three targeted group: Design Division, Construction Division, and
Maintenance Division.
3.6 Data collection The researcher conducted interviews with design team, project manager and
maintenance engineer at Infrastructure and Camp Improvement Programmed (ICIP).
The second component of the data collection is in depth interviews with ten key
experts in construction field. A structured interview conducted with the design team
and managers by the researcher. Notes have been taken through the interviews and
41
they were recorded to allow further capturing of information, in addition to
preliminary resources that not available in secondary resources through distributing
questionnaires on evaluating the buildability concept influencing quality of building
during design process in "UNRWA Building" in Gaza Strip. Research methodology
depends on the analysis of data on the use of descriptive analysis, which depends on
the poll and use the main program (SPSS).
3.7 Research population and sample size The population of the study is the UNRWA Engineers. The sample with size was 95
engineers that they works in Infrastructure and camp Improving Programme (ICIP)
includes experienced design engineers, construction engineers, maintenance
engineers and quantity surveyor. 95 questionnaires were distributed to the research
population and 63 questionnaires were received.
3.8 Questionnaire content
The questionnaire was provided with a covering letter explaining the purpose of the
study, the way of responding, the aim of the research and the security of the
information in order to encourage a high response. The questionnaire included
multiple choice questions: which used widely in the questionnaire. The variety in
these questions aims first to meet the research objectives, and to collect all the
necessary data that can support the discussion, results and recommendations in the
research. All questions follow lekart scale as shown in Table (3-1).
Table ( 3-1): Questions scale
Level 1 Very low
important
Low
important
Medium
important
High
important
Very high
important
Level 2
Very
difficult to
build
Difficult to
build Buildable Easy buildable
Very easy
buildable
Scale 1 2 3 4 5
3.9 Pilot study
A pilot study for the questionnaire was conducted before collecting the results of the
sample. It provides a trial run for the questionnaire, which involves testing the
42
wordings of question, identifying ambiguous questions, testing the techniques that
used to collect data, and measuring the effectiveness of standard invitation to
respondents. To assess the questionnaire validity, a pilot study was performed with
seven selected professionals who are closely involved in building design,
construction and maintenance and they have extensive experience. Seven
professionals of the pilot study have been chosen, four professionals from design
division, two professional from construction division, one professional from
maintenance division, were asked to verify the validity of the questionnaire issues
and its relevance to the research objectives.
There are many comments and suggestions were collected and evaluated carefully.
All the suggested comments and modifications were checked by the supervisor
before taking them into consideration. At the end of this process, modifications and
additions were introduced to the questions and the final questionnaire was
constructed. Some of their modifications are:
Added sub factor related to the lessons learned that arising from maintenance field,
the project components was modified to be more specific, check that design have
positive environmental impact was added. The experts mentioned that coordination
of information during design process may have effect of builability problem. Lack of
coordination was modified to poor communication among design team to be more
specific.
3.10 Validity of research
The validity of an instrument is defined as a determination of the extent to which the
instrument actually reflects the abstract construct being examined. "Validity refers to
the degree to which an instrument measures what it is supposed to be measuring".
High validity is the absence of systematic errors in the measuring instrument. When
instrument validity is truly reflects the concept it is supposed to measure. Achieving
good validity required the care in the research design and sample selection. The
questionnaire was checked by the supervisor and three expertise’s in the designing
and construction environments to evaluate the procedure of questions and the method
of analyzing the results. The expertise agreed that the questionnaire was valid and
suitable enough to measure the purpose that the questionnaire designed for.
43
3.11 Content validity of the questionnaire
Content validity test was conducted by consulting two groups of experts. The first
was requested to evaluate and identify whether the questions agreed with the scope
of the items and the extent to which these items reflect the concept of the research
problem. The other was requested to evaluate that the instrument used is valid
statistically and that the questionnaire was designed well enough to provide relations
and tests between variables. The two groups of experts did agree that the
questionnaire was valid and suitable enough to measure the concept of interest with
some amendments.
3.12 Statistical validity of the questionnaire
To insure the validity of the questionnaire, two statistical tests should be applied. The
first test is Criterion-related validity test (Pearson test) which measures the
correlation coefficient between each item in the field and the whole field. The second
test is structure validity test (Pearson test) that used to test the validity of the
questionnaire structure by testing the validity of each field and the validity of the
whole questionnaire. It measures the correlation coefficient between one filed and all
the fields of the questionnaire that have the same level of similar scale.
3.13 Criterion related validity
1) Internal consistency
Internal consistency of the questionnaire is measured by a scouting sample, which
consisted of 35 questionnaires, through measuring the correlation coefficients
between each paragraph in one field and the whole filed. Tables below show the
correlation coefficient and p-value for each field items. As shown in the table the p-
Values are less than 0.05 or 0.01, so the correlation coefficients of this field are
significant at α = 0.01 or α = 0.05. It can be said that the paragraphs of this field are
consistent and valid to measure what it was set for.
44
Table ( 3-2): The correlation coefficient for buildability concept influencing quality of building design
Table ( 3-3): The correlation coefficient for factors that cause’s buildability problem due to designers
No Buildability concept influencing quality of building design Pearson
coefficient
P-
value
1. Site condition should be investigated to avoid subsequent
delays
.463 .005
2. Simplify and standardize construction details .591 .002
3. Prefabricate building components and/or modularize
construction .648
0.00
4. Standardize repeatable components to reduce waste and
increase construction efficiency .538 .001
5. Reduce area distributed during construction to avoid additional
landscaping costs .418 .003
6. Reduce unnecessary design requirements .756 0.00
7. Use methods and materials that allow for ease of
reconfiguration, renovation or deconstruction .612 0.00
8. Select all material based on the update availability in local
marketing .664 0.00
9. Minimizing the time of underground construction .649 0.00
10. Coordination of design information (drawings, specification,
documentation and management) .617 0.00
No. Factors that causes buildability problem due to designers Pearson
coefficient
P-
value
1. Lack of buildability review for design .563 0.005
2. Lack of effective management response .491 .004
3. Insufficient and unrealistic constraints of available material .648 0.000
45
Table (3-3):Continue
4. Inadequate the contractor resources .538 .001
5. Poor communication among design team .723 .002
6. Poor client briefing .533 0.001
7. Poor designer briefing .659 .004
8. Lack of project definition .482 .003
9. Inadequate designer technical knowledge .693 0.000
10. Poor specification .597 .000
11. Unclear details of drawing .521 .001
12. Design changes .680 0.000
13. Insufficient and unrealistic constraints of project time .633 0.000
14. Insufficient and unrealistic constraints of project cost .620 0.000
15. Education and training on Buildability are not provided to
designer .577 0.000
16. Designer don’t have adequate time to give sufficient attention
to buildability 0.725 0.002
17. Manager don’t have adequate time to give sufficient attention
to buildability .492 .003
18. The lessons-learned that arising from construction field are not
documented .553 .001
19. The lessons-learned that arising from maintenance field are not
documented
.633 0.000
46
Table ( 3-4): The correlation coefficient for factors that influencing in the design process
No. Factors that influencing in the design process Pearson
coefficient
P-
value
1. Review designs regularly to ensure that the requirements of the
definitive project brief are met in (the schedules of areas, room
data sheets, specifications and cost)
0.619 0.000
2. Submission of design information that can be readily
understood 0.609 0.000
3. Site condition should be investigated to avoid subsequent
delays 0.813 0.000
4. Check that the designs are efficiently use the space 0.596 0.001
5. Check that the designs have a positive environmental impact 0.435 0.004
6. Check that the designs are meeting the security and safety
regulations 0.491 0.003
7. Check that the designs consider the energy efficient buildings 0.812 0.000
8. Check that the designs are improvable 0.626 0.000
9. Check that the materials used that can be easily maintained and
durable 0.568 0.000
10. The Client is satisfied on design when all elements of the
design are discussed and approved 0.639 0.000
11. Developing standard checklists-completeness of information on
drawings. 0.554 0.001
12. Check that design consider the contractor available resources 0.545 0.001
13. Check the site condition and soil test 0.688 0.005
14. Sharing the knowledge of other professionals and teamwork
during the design stage 0.453
0.006
15. Effect of code and standards on quality of design 0.478 0.004
16. Effectiveness of lessons-learned programs during design
process 0.433 0.009
47
Table ( 3-5): The correlation coefficient for facades finishing material affecting buildability
Table (3-4):Continue
17. Effectiveness of lessons-learned programs during
implementation 0.589
0.000
18. Making design decisions on cost 0.735 0.000
19. Making design decisions on time 0.731 0.000
20. Check that design information are documented 0.620 0.000
No. Facades finishing material affecting buildability of building
design
Pearson
coefficient
P-
value
A External and internal facades finishing material
1. Fair face concrete 0.481 0.002
2. Traditional plaster and paint 0.564 0.000
3. Granite , stonework, ceramic 0.631 0.000
4. Cladding metal 0.620 0.000
5. Glass work 0.515 0.002
6. Steel roof slab 0.660 0.00
7. Concrete staircase 0.551 0.01
8. Steel staircase 0.543 0.01
9. Precast RC wall with pre-installed windows and finishes 0.702 0.000
10. Aluminum curtain wall
0.557 0.01
11. Internal tiling finishing material easy to maintain and durable 0.613 0.000
12. External pavement finishing material easy to maintain and
durable
0.564 0.00
48
3.14 Structured validity of the questionnaire
Structured validity is the second statistical test that used to test the validity of the
questionnaire structure by testing the validity of each field and the validity of the
whole questionnaire. It measures the correlation coefficient between one filed and all
the fields of the questionnaire that have the same level of likert scale.
As shown in Table (3.6), the significance values are less than 0.05, so the correlation
coefficients of all the fields are significant at α = 0.05, so it can be said that the fields
are valid to be measured what it was set for to achieve the main aim of the study.
Table ( 3-6): Structure validity of questionnaire
No. Description
Pearson
correlation
coefficient
P-
value
1 Buildability concept influencing quality of building design 0.696 0.002
2 Factors that causes Buildability problem due to designers 0.832 0.000
3 Factors that influencing the design process .667 0.000
4 Facades finishing material affecting Buildability of building
design 0.881 0.000
3.15 Reliability of the research
Reliability of an instrument is the degree of consistency with which it measures the
attribute it is supposed to be measuring. The test is repeated to the same sample of
people on two occasions and then compares the scores obtained by computing a
Table (3-5): Continue
B Roof /Slab covering
1 Composite type slab 0.923 0.000
2 Waterproofing membrane with protective layer 0.535 0.005
3 Liquid applied waterproofing with protective layer 0.338 0.004
4 Expansions joint 0.703 0.000
49
reliability coefficient. For the most purposes reliability coefficient above 0.7 are
considered satisfactory. Period of two weeks to a month is recommended between
two tests. Due to complicated conditions that the contractors are facing at the time
being, it was too difficult to ask them to responds to our questionnaire twice within
short period. The statistician's explained that, overcoming the distribution of the
questionnaire twice to measure the reliability can be achieved by using Cronbach’s
Coefficient Alpha and Half Split Method through the SPSS software.
3.16 Half Split Method
This method depends on finding Pearson correlation coefficient between the means
of odd rank questions and even rank questions of each field of the questionnaire.
Then, correcting the Pearson correlation coefficients can be done by using Spearman
Brown correlation coefficient of correction. The corrected correlation coefficient
(consistency coefficient) is computed according to the following equation:
Consistency coefficient = 2r/(r+1), where r is the Pearson correlation coefficient. The
normal range of corrected correlation coefficient 2r/(r+1) is between 0.0 and + 1.0
As shown in Table (3.7), all the corrected correlation coefficients values are between
0.8409 and 0.8966 and the general reliability for all items equal 0.8588, and the
significant (α ) is less than 0.05 so all the corrected correlation coefficients are
significant at α = 0.05. It can be said that according to the Half Split method, the
dispute causes group are reliable.
Table ( 3-7): Half Spit coefficient method
No. Description Person- correlation
Spearman-Brown
Coefficient
Sig. (2-Tailed)
1 Buildability concept influencing quality of building design 0.8125 0.8966 0.000
2 Factors that causes buildability problem due to designers 0.7255 0.8409 0.000
3 Factors that influencing the design process 0.7725 0.8717 0.000
4 Facades finishing material affecting Buildability of building design 0.7701 0.8693 0.000
Total 0.7525 0.8588 0.000
50
3.17 Cronbach’s Coefficient Alpha
This method is used to measure the reliability of the questionnaire between each field
and the mean of the whole fields of the questionnaire. The normal range of
Cronbach’s coefficient alpha value between 0.0 and + 1.0, and the higher values
reflects a higher degree of internal consistency. As shown in Table (3.8) The
Cronbach’s coefficient alpha was calculated for the first field of the buildability
concept influencing quality of building design, the second field of factors that causes
buildability problem due to designers the third field of the ranking of factors that
influencing of the design process, and the fourth field of the facades finishing
material affecting Buildability of building design. The results were in the range from
0.869 and 0.9215 and the general reliability for all items equal 0.9014. This range is
considered high; the result ensures the reliability of the questionnaire.
Table (3-8): Reliability Cronbach’s Alpha
No. Description Cronbach's
Alpha
1 Buildability concept influencing quality of building design 0.9215
2 Factors that causes Buildability problem due to designers 0.8719
3 Factors that influencing the design process 0.8759
4 Facades finishing material affecting Buildability of building design 0.869
Total 0.9014
3.18 Statistical manipulation
To achieve the research goal, the researcher used the Statistical Package for the
Social Science (SPSS) for manipulating and analyzing the data.
Statistical methods are as follows
1. Frequencies and Percentile.
2. Cronbach Alpha Test for measuring reliability of the items of the
questionnaires.
51
3. Person correlation coefficients for measuring validity of the items of the
questionnaires.
4. Spearman –Brown Coefficient.
5. One sample t test.
6. One Sample Analysis of Variance (ANOVA)
3.19 Chapter summary
This chapter was talking about the research methodology, the population, the sample
size, the validity and reliability of the questionnaire.
The researcher conducts the descriptive approach and depends on two main types of
data: primary, the questionnaire, interview and case study, secondary: books, articles
and thesis.
52
Chapter 4 ANALYSIS AND DISCUSSIONS
4.1 Introduction This chapter analyse and discusses the results that have been collected from field
surveys of (63) questionnaires. The research population was limited to a group of
respondent in UNRWA. The results were recorded and processed according to the
methodology detailed in chapter three. Part one of the questionaire represents the
profiles and all necessary information about the respondents. Part two designed to
attain the objectives in this research. The research aim to investigate the buildability
during the design stage, which could improve the project performance as well as the
project schedule and increase the quality of building during of the operation and
maintenance stages in Gaza UNRWA projects.
4.2 General information This section will discuss and analyze the first part of the questionnaire, it includes the
position of respondents, years of experience in the construction industry, academic
qualification, the major of sample experience, years of works in organization, term of
buildability main impact, and the desgin process and quality of building
performance.
4.2.1 Position of respondent Table (4.1) shows the position respondents result 7.9% from the sample are "
Architect ", and 19 % from the sample are " Structural Eng. ", and 54 % from the
sample are " Construction Eng. " and 7.9 % from the sample are " Maintenance Eng.
", and 3.2 % from the sample are " Quantity surveyor" and 7.9 % from the sample
are " Project Manager”. It should be noted that constructions Eng. Is around half of
the sample size which means that target group had an enough experience in
construction to give good opinion.
53
Table (4-1): Position of respondent
Position of respondent Frequency Percentages
Architect 5 7.9
Structural Eng. 12 19
Construction Eng. 34 54
Maintenance Eng. 5 7.9
Quantity surveyor 2 3.2
Project Manager 5 7.9
Total 63 100.0
4.2.2 Years of experience in the construction industry Figure (4.1) shows the years of experience results, that 4.8 % from the sample are
"Less than 5 years ", and 30.2% from the sample are "from 5-10 years ", and 38.1 %
from the sample are "From 11-15 years ", and 7.9% from the sample are from "16-20
years ", and 19 % from the sample are more than 21 years. It should be noted that
almost 65% of the respondent had more than 10 years’ experience which means that
target group had the enough experience.
Figure ( 4-1) Years of experience in the construction industry
54
4.2.3 Academic qualifications Table (4.2) shows results of academic qualification, that 1.6 % from the sample has
“Diploma” and 77.8% from the sample have "Bachelor", and 19 % from the sample
have "M.Sc.", and 1.6 % from the sample has "Ph.D.".
The results indicate that the majority of the working staff in UNRWA are highly
educated and hold a bachelor degree, which gives an indication that the qualifications
of the respondents qualify them to give good opinions.
Table (4-2): Academic qualification
Academic Qualifications Frequency Percentages
Diploma 1 1.6
B.Sc. 49 77.8
M.Sc. 12 19
Ph.D. 1 1.6
Total 63 100.0
4.2.4 The major of the sample experience Table (4.3) shows the results of the major of experience, that 15.9 % from the sample
are "Design ", and 73% from the sample are "Construction ", and 6.3 % from the
sample are "Maintenance ", and 4.8 % from the sample are "Project management ". It
should be noted that almost 88.9% of the respondent had major of experience in
design and construction which means that target group had the enough experience.
Table ( 4-3): The major of the sample experience
The major of experience Frequency Percentages
Design 10 15.9
Construction 46 73
Maintenance 4 6.3
Project management 3 4.8
Total 63 100.0
55
4.2.5 Years of works in organization Figure (4.2) shows results regarding the respondent’s years of working that 7.9%
from the sample are working “Less than 2 years”, and 30.2% from the sample are
working from “2-5 years”, and 20.6% from the sample are working from “6-10
years”, and 41.3 % from the sample are working “More than10 years”. It’s clear that
majority of respondents (41.3%) had more than 10 years of working in organization
which mean that target group had the enough experience in UNRWA projects.
Figure (4-2): Years of works in organization
4.2.6 Term of buildability main impact Figure (4.3) shows that 25.3% from the sample believe that the buildability main
impact is in " Design stage ", and 60.3% from the sample believe that buildability
main impact is in " Construction stage ", and 14.3% from the sample believe that
buildability main impact is in " Operation and maintenance stage ". This result is
supported by (Lam, et al. 2006) research; they mentioned that the implementation of
buildability management can lead to significance quantifiable improvements in
project performance in terms of time, cost and quality.
56
Figure ( 4-3): Term of buildability main impact
4.2.7 The design process and quality of building performance
Table (4.4) shows that 19% from the sample believe that the percentage of
involvement of the design process have in the establishment of quality of building
performance are from "25-50%", and 33.3% from the sample believe that the
percentage of involvement of the design process have in the establishment of quality
of building performance are from "51-75%", and 47.6% from the sample believe that
the percentage of involvement of the design process have in the establishment of
quality of building performance are "More than76%". These results are comported
with most studies (Lam et al. 2006) which confirmed the positive relationships
between improved buildability and saving in project cost and time, as well as better
safety and quality performance. Hamzaha et al. (2011) in their research find that
more than 50% of changes in orders are caused by faulty design, and the design
process was realized that 80% of the construction cost was taken as soon as the
design sketch was made.
Table ( 4-4): The percentage of involvement of the design process
The percentage of involvement of
the design process Frequency Percentages
Less than 25% 0 0
25-50% 12 19
51-75% 21 33.3
More than76% 30 47.6
Total 63 100.0
57
4.3 One Sample K-S Test One Sample K-S test was used to identify if the data follow normal distribution or
not. This test is considered necessary in case of testing hypotheses as most
parametric test stipulate data to be normally distributed and this test used when the
size of the sample are greater than 30.
Test results as shown in Table (4-5), clarifies that the calculated p-value is greater
than the significant level which is equal 0.05 (p-value > 0.05). This in turn denotes
that data follows normal distribution, and so parametric tests must be used.
Table ( 4-5): One Sample K-S
No. Category Statistic P-value
1 Buildability concept 0.709 0.597
2 Buildability problem 0.999 0.271
3 Ranking of factors influencing in the design process 1.191 0.117
4 Facades finishing material affecting buildability of building
design 0.875 0.624
Total 0.989 0.482
4.4 Discussion and hypotheses test In the following sections, a one sample t test was used to test if the opinion of the
respondent in the content of the sentences are positive ( weight mean greater than
"60%" and the p-value less than 0.05) or the opinion of the respondent in the content
of the sentences are neutral ( p- value is greater than 0.05) or the opinion of the
respondent in the content of the sentences are negative (weight mean less than "60%"
and the p-value less than 0.05).
The researcher uses a one sample t test and evaluates the buildability concept
influencing quality of building during design process in UNRWA projects and the
results shown in sections below.
58
4.5 Buildability concept influencing quality of building design Table (4.6) show that the mean for all items equal 4.24 and the weighted mean
equal 84.76% which is greater than "60%" and the value of t test equal 10.586
which is greater than the critical value which is equal (1.99). The p- value equal
0.000 which is less than 0.05, that means the Buildability concept is statistically
significant at the 0.05 level on the influencing quality of building design in Gaza
Strip.
The result show that the majority of respondents (4.98) agreed that coordination of
design information (drawings, specification, documentation and management) are
most important in buildability concept that influencing quality of building design.
Where (4.43) of respondents find that they used methods and materials that allow for
ease of reconfiguration, renovation or deconstruction, and (4.27) of them find the
select of all material based on the update availability in local marketing, where the
lowest is minimizing the time of underground construction with (3.56) and reduced
area distributed during construction to avoid additional landscaping cost with (3.25)
of respondents.
This result is consistent with Mydin et al. (2011) research. They indicated that
providing clear and complete design information is very important to consider during
design process, where the lowest rank is less work below ground.
Table ( 4-6): Buildability concept influencing quality of building design
No. Buildability concept Mean Standard
deviation
Weighte
d mean
T-
value
P-
value Rank
1 Site condition should be
investigated to avoid subsequent
delays
4.25 0.69 85.08 14.324 0.00 4
2 Simplify and standardize
construction details 3.70 0.80 73.97 6.965 0.00 6
3 Prefabricate building components
and/or modularize construction 3.98 0.77 79.68 10.114 0.00 5
59
4.6 Factors that causes buildability problem due to designers
Table (4.7) show that the mean for all items equal 4.30 and the weighted mean equal
86.03% which is greater than "60%" and the value of t test equal is 13.697 which
is greater than the critical value (1.99) and the p- value equal 0.000 which is less
than 0.05. This means that the factors that cause a problem to use Buildability due to
designers are statistically significant at the 0.05 level.
These result shows that there are 13 factors with mean value above 4.00, and 6
factors with mean value below 4.00. The majority of respondents (4.51) consider that
don’t provide designer the education and training on buildability are the most
important factors that causes buildability problem due to designer, where (4.29) of
Table(4-6):continue
4
Standardize repeatable components
to reduce waste and increase
construction efficiency
3.63 4.12 72.70 1.222 0.23 8
5
Reduce area distributed during
construction to avoid additional
landscaping costs
3.25 0.95 65.08 2.122 0.04 10
6 Reduce unnecessary design
requirements 3.65 0.83 73.02 6.252 0.00 7
7 Use methods and materials that
allow for ease of reconfiguration,
renovation or deconstruction
4.43 0.69 88.57 16.45
8 0.00 2
8 Select all material based on the
update availability in local
marketing
4.27 0.92 85.40 10.96
2 0.00 3
9 Minimizing the time of
underground construction 3.56 0.86 71.11 5.144 0.00 9
10 Coordination of design information
(drawings, specification,
documentation and management)
4.98 6.46 99.68 2.438 0.02 1
Total 4.24 0.93 84.76 10.58
6 0.00
60
respondents think that no documentation for the lesson learned that arising from
maintenance filed and lack of effective management response have important factors.
(4.17) of respondents consider that lack of project definition has important factor,
(4.11) of respondents find that lack of buildability review for design has important
factor, (4.10) of respondents consider that inadequate designer technical knowledge has
important factor, where the lowest factors causes buildability problem due to
designers are insufficient and unrealistic constraints of project cost (3.65), design
changes (3.70), unclear details of drawing (3.87) and poor designer briefing (3.90).
These results are comported with Wong et al. (2006) research which identified the
main factors related of the designer such as i)Lack of knowledge ii)Experience in
construction ii) Designing without input or the involvement of contractors.
Table ( 4-7): Factors that cause’s buildability problem due to designers
No. Buildability problem Mean Standard
deviation
Weighte
d mean
T-
value
P-
valu
e
1 Lack of Buildability review for design 4.11 0.72 82.22 12.23
3 0.00
2 Lack of effective management
response 4.29 0.83 85.71
12.27
4 0.00
3 Insufficient and unrealistic constraints
of available material 4.06 0.80 81.27
10.54
3 0.00
4 Inadequate the contractor resources 4.06 0.74 81.27 11.44
2 0.00
5 Poor communication among design
team 4.05 0.83 80.95
10.00
1 0.00
6 Poor client briefing 4.03 0.93 80.63 8.780 0.00
7 Poor designer briefing 3.90 1.10 78.10 6.511 0.00
8 Lack of project definition 4.17 0.93 83.49 10.07
6 0.00
9 Inadequate designer technical
knowledge 4.10 0.95 81.90 9.194 0.00
61
4.7 Factors that influencing the design process Table (4.8) show that the mean for all items equal 3.60 and the weighted mean equal
72.06% which is greater than "60%" and the value of t test equal 5.88 which is
greater than the critical value (1.99). The p- value equal 0.000 which is less than
0.05. This means that the design process factors are statistically significant at the
0.05 level.
These result shows that there are 12 factors with mean value above 4.00, and 8
factors with mean value below 4.00. The first most five important factors that
influencing of the design process; are check that design considers the contractor
available resources (4.33), the effect of code and standards on quality of design
(4.30), sharing the knowledge of other professionals and teamwork during the design
Table(4-7):Continue
10 Poor specification 4.08 0.85 81.59 10.10 0.00
11 Unclear details of drawing 3.87 0.83 77.46 8.322 0.00
12 Design changes 3.70 0.91 73.97 6.096 0.00
13 Insufficient and unrealistic constraints
of project time 3.65 1.00 73.02 5.152 0.00
14 Insufficient and unrealistic constraints
of project cost 3.95 0.91 79.05 8.346 0.00
15 Education and training on Buildability
are not provided to designer 4.51 6.52 90.16 1.836 0.00
16 Designer don’t have adequate time to
give sufficient attention to buildability 3.73 0.85 74.60 6.847 0.00
17 Manager don’t have adequate time to
give sufficient attention to buildability 4.08 0.83 81.59
10.33
5 0.00
18 The lessons-learned that arising from
construction field are not documented 4.06 0.95 81.27 8.902 0.00
19 The lessons-learned that arising from
maintenance field are not documented 4.29 0.81 85.71
12.57
1 0.00
Total 4.30 0.75 86.03 13.69
7 0.00
62
stage (4.24), check that the designs consider the energy efficient building (4.22), and
check that the designs are improvable (4.1). It is clear that the respondents ranked
this factor in rank fourth but researcher thinks the bad situation and the shortage of
electricity in Gaza strip give acceptance clearance of this ranking. Were the lowest
five factors that influencing of design process are making design decisions on
time(3.35), check the site condition and soil test (3.52), check that design
information are documented (3.54), check that the designs have a positive
environmental impact (3.65), and the client is satisfied on design when all elements
of the design are discussed and approved (3.76).
Table ( 4-8): Factors that influencing the design process
No. Factors that influencing of the
design process Mean
Standard
deviation
Weighted
mean
T-
value
P-
value Rank
1
Review designs regularly to ensure
that the requirements of the
definitive project brief are met in
(the schedules of areas, room data
sheets, specifications and cost)
4.10 0.80 81.90 10.90 0.00 10
2 Submission of design information
that can be readily understood 4.03 0.69 80.63 11.79 0.00 11
3
Site condition should be
investigated to avoid subsequent
delays
3.86 1.05 77.14 6.51 0.00 15
4 Check that the designs are
efficiently use the space 4.14 1.03 82.86 8.81 0.00 6
5 Check that the designs have a
positive environmental impact 3.65 0.95 73.02 5.42 0.00 17
6 Check that the designs are meeting
the security and safety regulations 3.94 0.84 78.73 8.85 0.00
13
7
Check that the designs consider the
energy efficient buildings
4.22 0.85 84.44 11.40 0.00 4
63
Table(4-8):Continue
8 Check that the designs are
improvable 4.14 0.80 82.86 11.33 0.00 5
9
Check that the materials used that
can be easily maintained and
durable
3.86 0.80 77.14 8.50 0.00 14
10
The client is satisfied on design
when all elements of the design are
discussed and approved
3.76 1.01 75.24 5.98 0.00 16
11 Developing standard checklists-
completeness of information on
drawings
4.13 0.91 82.54 9.86 0.00 7
12 Check that design consider the
contractor available resources 4.33 0.70 86.67 15.21 0.00 1
13 Check the site condition and soil
test 3.52 1.05 70.48 3.98 0.00 19
14 Sharing the knowledge of other
professionals and teamwork during
the design stage
4.24 0.69 84.76 14.26 0.00 3
15 Effect of code and standards on
quality of design 4.30 0.78 86.03 13.32 0.00 2
16 Effectiveness of lessons-learned
programs during design process 4.10 0.78 81.90 11.19 0.00 9
17 Effectiveness of lessons-learned
programs during implementation 4.02 0.83 80.32 9.68 0.00 12
18 Making design decisions on cost 4.11 0.92 82.22 9.61 0.00 8
19 Making design decisions on time 3.35 0.97 66.98 2.86 0.01 20
20 Check that design information are
documented 3.54 1.01 70.79 4.23 0.00 18
Total 3.60 0.81 72.06 5.88 0.00
64
4.8 Project component weighting
Table (4.9) show that the mean of envelop system (exterior and interior wall,
foundation) are (19.56%), and the mean of structural frame system are (14.47%), and
the suggested mean of slab and roof system are (13.41%), and the suggested mean
of vertical transportation structures, such as stairs, lifts, ramps etc. are (10), and the
mean of site specific factors (retaining wall, leveling, others) are (10.19%), and the
mean of building finishes (doors, windows, painting, tilling, others) are (19.19%),
and the mean of services (plumbing & internal drainage electric power & lighting,
others) are (13.32%).
These result shows that there are two main component that have majority effect in
the cost of building; envelop system and building finishes, these results are
comported with researcher hypothesis which identified the main facades finishing
material affecting buildability of building design.
Table ( 4-9): Project component weighting
No. Component Mean of
weighting%
Minimum
Value
Maximum
Value
1 Envelop system
(exterior and interior wall, foundation) %19.56 %5 %60
2 Structural frame system %14.47 %5 %60
3 Slab and roof system %13.41 %5 %40
4 Vertical transportation structures, such as stairs,
lifts, ramps etc. %10 %1 %20
5 Site specific factors
(Retaining wall, leveling, Others) %10.19 %2 %30
6 Building finishes
(Doors, windows, painting, tilling, others) %19.19 %2 %50
7 Services (Plumbing & Internal drainage Electric
power & lighting, Others) %13.32 %2 %40
Total 100%
65
4.9 Facades finishing material affecting Buildability of building design
A. External and internal facades finishing material
Table (4.10) show that the mean for all items equal 3.35 and the weighted mean
equal 66.98% which is greater than "60%" and the value of t test equal 3.35 which is
greater than the critical value which is equal 1.99 and the p- value equal 0.000 which
is less than 0.05. This means that external facades finishing material have statistically
significant effect on the Buildability of building design at the 0.05 level.
From the study results, the researcher believe that the outcomes from the study can
be used to improve the quality of building design by considering the quality facades
finishing often when buildability as discussed and considered, the result shows that
there are two main component that have major effect in the cost of building; envelop
system and building finishes, these results are comported with Lam et al. (2011)
research.
Internal tiling finishing material and external pavement finishing material were given
the highest buildability ranking because of its easy working conditions, RC wall and
steel works were given difficult to build ranking as they are mostly fabricated of site.
Fair face concrete was given lower buildability ranking because off high lack of good
workmanship to execute fair face concrete.
Table ( 4-10): Facades finishing material affecting buildability of building design
No. External facades finishing
material Mean
standard
deviation
Weighted
mean t-value
P-
value
1 Fair face concrete 3.38 0.81 67.62 3.72 0.00
2 Traditional plaster and paint 3.38 0.85 67.62 3.55 0.00
3 Granite , stonework, ceramic 3.49 0.90 69.84 4.36 0.00
4 Cladding metal 3.79 0.83 75.87 7.62 0.00
5 Glass work 3.46 1.04 69.21 3.50 0.00
6 Steel roof slab 3.32 0.91 66.35 2.76 0.01
7 Concrete staircase 3.38 0.96 67.62 3.16 0.00
66
B. Roof /Slab covering
Table (4.11) show that the mean for all items equal 3.73 and the weighted mean
equal 74.67% which is greater than "60%" and the value of t test equal 5.02 which is
greater than the critical value which is equal 1.99 and the p- value equal 0.000 which
is less than 0.05. This means that Roof /Slab covering has statistically significant
effect on the Buildability of building design at the 0.05 level as follows.
These result shows that liquid applied waterproofing with protective was given the
highest buildability ranking more than proofing membrane because of its easy
working conditions, composite type slab was given buildability ranking as they are
mostly need considering the contractors resources and skills.
Table ( 4-11): Facades finishing material affecting building of design "Roof/Slab
covering"
Table(4-10):continue
8 Steel staircase 3.67 0.90 73.33 5.89 0.00
9 Precast RC wall with pre-
installed windows and finishes 3.62 0.96 72.38 5.13 0.00
10 Aluminum curtain wall 3.40 0.96 67.94 3.28 0.00
11 Internal tiling finishing material
easy to maintain and durable 3.86 0.95 77.14 7.18 0.00
12 External pavement finishing
material easy to maintain and
durable
3.76 0.71 75.24 8.49 0.00
Total 3.35 0.83 66.98 3.35 0.00
No. Roof /Slab covering
Mean Standard
deviation
Weight
mean t-value P-value
1 Composite type slab 3.97 1.13 79.43 6.82 0.00
2 Waterproofing membrane with
protective layer 4.03 0.58 80.69 14.25 0.00
67
4.10 One way ANOVA
There were statistically significant differences at the 0.05 level in the views of the
engineers in UNRWA about the possibility of the use buildability influencing quality
of building due to the position of respondent.
To test the hypothesis we use the one way ANOVA and the result illustrated in Table
(4.12) which show that the p-value equal 0.635 which is greater than 0.05 that’s
means there were no statistically significant differences at the 0.05 level in the views
of the engineers in UNRWA about the possibility of the use of the buildability
influencing quality of building due to the position of respondent.
Table (4.12) one way ANOVA test for difference in point of view of UNRWA
engineers about the possibility of the use of the buildability influencing quality of
building due to the position of respondent.
Table ( 4-12): One way (ANOVA) of difference in point of views of due to position
of respondent
Field Source
Sum of
Squares
Mean
Square
F
value
Sig.(P-
Value)
The possibility of the use of the build ability
influencing quality of building due to the
position of respondent.
Between
Groups 0.300 0.100
0.573 0.635 Within
Groups 9.612 0.175
Total 9.912
Significance level 0.05
Table(4-11) Continue
3 Liquid applied waterproofing with
protective layer 4.05 0.48 81.03 17.32 0.00
4 Expansions joint 3.50 0.46 69.97 8.58 0.00
Total 3.73 1.16 74.67 5.02 0.00
68
There were statistically significant differences at the 0.05 level in the views of
UNRWA engineers about the possibility of the use buildability influencing quality of
building due to the major of experience.
To test the hypothesis we use the one way ANOVA and the result illustrated in Table
(4.13) which show that the p-value equal 0.183 which is greater than 0.05 that’s
means there were no statistically significant differences at the 0.05 level in the views
of UNRWA engineers about the possibility of the use build ability influencing
quality of building due to the major of experience.
Table ( 4-13): One way (ANOVA) of difference in point of views of due to experience
Field Source
Sum of
Squares
Mean
Square
F
value
Sig.(P-
Value)
The possibility of the use of the build
ability influencing quality of building
due to experience
Between
Groups 0.831 0.277
1.677 0.183 Within
Groups 9.081 0.165
Total 9.912
Significance level 0.05
69
Chapter 5 INTERVIEW AND CASE STUDY
5.1 Structured interiew
5.1.1 Introduction
To explore and identify the most effective factors and level of knowledge in
buildability, a structured interview related of buildability concept was conducted.
The interviews designed to facilitate flow of ideas. The followings open end
questions were listed to give the interviewee an indication of information requested.
1. Which of site condition and site layout are important to buildability?
2. What are your suggestions for improving the design details?
3. Does the buildability affect construction cost?
4. What are the project benefits of improved buildability?
5. Is there an effect of buildability on safety?
6. Which of precast elements or traditional methods are necessary to improve
buildability?
7. Does the buildability consider the contractor resourses?
Table ( 5-1): Profile of interviews
Interviewee Sectore No of interviews
Architect engineer Working in building desgin 3
Civil engineer Working in strucure desgin 1
Site engineer Working in construction 2
Site engineer Working in maintenance 1
Civil engineer Working in infrastructure design 2
Quantity serviour Working in building design 1
Quality engineer Working in quality control 1
Total of interviewee 11
70
5.1.2 Interviews finding
The collective openinnos and inputs relating to number of structuerd interview,
questions are summarised below:
All the interviews agreed that the quality of design is important to improve the
building performance and building as designed, e.g. use modular design with
standard details that are compatible with other system, dimensional and functional,
e,g. use assembly technologies and avoid to use specialsit technologies that may need
specialist labor and equipment, e.g. icrease the communication process between all
parties who are involved in the project to have the leseon learnd more achievable.
All the interviews agreed that site condition and site layout are important to
buildability and the following factors were discussed:
Soil test, leveling, existing building, geograghic view, oriantation, and inferstrucure
conditions.
All the interviews agreed that the buildability affect construction cost.
All the respondents agreed that the quality of design should be clearly considered
during the early stages in design. The following suggestions were given for
improving of design details:-
a) Use of standerd details ;
b) Minimise the repetition of construction details;
c) Increase the co-ordination of architecural, structural and services desgin;
d) Use of available local materials;
e) Review designs and discuss with end user to ensure that they satisfy the needs
expressed in the definitive project brief;
f) Review desgin details with construction team;
g) Investigate the environment of site location;
h) Effectiveness of lessons-learned programs during construction;
i) Site visits by all design team;
j) Sharing the knowledge of contractors, site engineer and teamwork during the
design stage;
k) Develop standard checklists;
71
The interviews from design team stated that the time frame for designing and
tendering should be enough to prepare careful design and pricing.
The interviews from site engineer stated that the design detail problems are due to
lack of construction knowledge, The specification levels of mateiral don’t fall in the
scope of buildability consideration, e.g. using uavilable material would affect on cost
and time frame. Using flexable standard details in the repetitive works.
All the interviews find the following benefits of improved buildability:-
a. The project can be efficiently constructed as accurate construction project
planning;
b. Project duration might be reduced;
c. Less variation orders and less interruption caused by impractical design
details;
d. The construction of project will be executed as designed since less conflict
between parties over design solution would be encountered;
e. Creating a flexible, durable and sustainable construction by producing design
that are easy and cost effective to manage and maintain;
f. Effectiveness of lessons-learned programs during design;
g. Making design decisions on cost;
All the interviews find that there is effect of buildability on safety, as the buildability
is concerned with how a designer facilitat efficiently the ease and safety of
construction, it is directly related to the use of contractors resourse during
implementation process.
72
5.2 Case study 5.2.1 Introduction
One health center and two UNRWA school projects were selected for validating the
results of this research. These projects were selected because they are representing
the common building types executed by UNRWA. The projects are easily accessible
to collect the data to get in-depth information about the buildability factors that
influencing the design process. The details of the three case studies are presented
5.2.2 Case study (A): Health Center This project consists of main building with ground floor, first floor, second floor and
third floor. The total area is 4,600m2. Steel shed; boundary walls and landscaping
works are attached to the main building. The full detailed design was prepared by
design division to have good buildability of design. Supervision was carried out by
construction division in UNRWA, Gaza.
In case study (A) it is noted that justification for the variation orders as
followings:
New items required to complete the works according to specification
Missed items in B.O.Q for some essential works.
Additional items were amended in the B.O.Q. to fit with the specific
requirements and user needs.
5.2.3 Case study (B): School No.1 This project consists of main building with ground floor, first floor, second floor and
third floor. With total built up area is 5500m2. The main building consists of all
standard school facilities in addition to canteen, concrete shed, boundary / retaining
wall, and landscaping works. The full detail design was prepared by design division
to have good buildability of design. The supervision was carried out by construction
division in UNRWA, Gaza.
In case study (B) it is noted that justification for the variation orders as
followings:
73
New items required to complete the works according to specification in order
to improve the quality and maintain more durability which affecting
positively on the operation of the school.
A shortage of quantities through design stage, therefore additional quantities
are required to complete the works according to specification and detailed
drawings.
Modification to the ceramic wall tiles in order to facilitate the maintenance
process during operation stage.
Additional items were amended in the B.O.Q. to fit with the specific
requirements and user needs.
Some alteration works were carried out.
5.2.4 Case study (C): School No.2
This project consists of main building with ground floor, first floor second floor and
third floor. The total built up area is 4300m2. The main building consists of all
standard school facilities in addition to canteen, steel shed, boundary wall, and
landscaping works. The full detailed design was prepared by design division to have
good buildability of design. The supervision was carried out by construction division
in UNRWA, Gaza.
In case study (C) it is noted that justification for the variation orders as
followings:
New items required to complete the works according to specification
Modification of the ceramic wall tiles in order to facilitate the maintenance
process during operation stage.
Additional items were amended in the B.O.Q. to fit with the specific requirements and user needs.
5.2.5 Data collection The data were collected through structured interviews with the project team leader,
and design team, from each project. These participants were selected as they
possessed the greatest understanding of the impact of buildability decisions on the
74
performance of the projects. Contract duration, actual duration, budgeted cost, were
collected and summarised in Table (5-2).
Table ( 5-2): Summary of Case Studies
Duration Cost
Contract
Duration
Delay (in
days)
Budgeted cost Actual cost
Case Study(A) 44 weeks 7 days 1,260,000 1,430,000
Case Study(B) 44 weeks 16 days 1,103,000 1,378,000
Case Study (c) 44 weeks 29 days 971,600 1,018,000
5.2.6 The case study finding It is noted that all of the case studies had a difference between the budgeted amount
and the actual implementation cost, which signify that there were inaccurate
estimates of some projects, or additional items was requested by the client to meet
the changes of the requirements. The case studies have viration order as aresult of
missing items and quainties in the original contract. The majority of implemintation
problem have been shown in facades finishing material which affect quality of
building during operation stage. There are many items that may reduce the repition
of maintenance work when designers consider the feedback by the maintenace teams.
These results are comported with the servey finding (see chapter 4).
Figure (5-1) shows that there are two main components that have major effect in the
cost of building; envelop system and building finishes. These results are comported
with researcher hypothesis which identified the main facades finishing material
affecting buildability of building design.
75
Envelop system, 20
Structural fram, 10
Slab and roof system, 7
Vertical transportation, 14
Site specific factors, 6
Building finishes, 30
Services, 13
0 5 10 15 20 25 30 35
Envelop system
Structural fram
Slab and roof system
Vertical transportation
Site specific factors
Building finishes
Services
Figure ( 5-1): Project component weighting
Table (5-3) show the result of the interview in the case studies, it was observed that
the most ten important factors causes buildability problem due to designers were: the
lack of buildability review for design with rank equals "1" were ranks equal “5” in
the result of survey, documentation of the lesson learned that arising from the field
maintenance team with rank equals “2’ and also ranks“2” in the survey.
Were the lack of effective management response with rank equals “3’ and also
ranks“3” in survey, lack of project definition with rank equals “4’ and also ranks“4”
in the survey, inadequate designer technical knowledge with rank equals “5’ were
ranks equal “6”.
In the result of survey, education and training on buildability are not provided to
designer with rank equals “6’ were ranks equal “1” in the result of survey, poor
specification with rank equals “7’ and also ranks“7” in the survey, insufficient and
unrealistic constrains of available material with rank equals “8’ were ranks equal “9”.
In the result of survey, manager don’t have adequate time to give sufficient attention to
buildability with rank equals “9’ were ranks equal “8” in the result of survey, and
inadequate the contractor resources with rank equals “10’ and also ranks“10” in the
survey.
76
Table ( 5-3): Factors that cause’s buildability problem due to designers (case study)
5.2.7 The major findings of the case studies are summarized as follows:- 1. The ICIP is developing the design process by applying the check list format. This
list was assigned by all participants in the design team. This is very important to
share the knowledge of other professionals and teamwork during the design
stage. This is factor was ranked No.7 in the researcher survey (see chapter4,
Table 4.8).
2. Most of construction teams believe that the poor details and specification are
essential factor that affects the way buildability review is conducted in the
design. This is factor was ranked No7 in the researcher survey (see chapter4,
Table 4.6).
3. There is no contractors involvement during the design process which mean that
desginers are not considering the contractor available resources and after the
design has been substantially completed and the specifications have been
developed
Factors
Rank
based on case
study
Rank
based on survey
Lack of Buildability review for design 1 5
The lessons-learned that arising from maintenance field are not
documented 2 2
Lack of effective management response 3 3
Lack of project definition 4 4
Inadequate designer technical knowledge 5 6
Education and training on Buildability are not provided to designer 6 1
Poor specification 7 7
Insufficient and unrealistic constraints of available material 8 9
Manager don’t have adequate time to give sufficient attention to
buildability 9 8
Inadequate the contractor resources 10 10
77
4. The design teams confirmed that the designer should be involved during
impelimintation process. This would create more efficiency to built the project as
designed, and apply the effectiveness of lessons learned in future projects.
5. The lessons learnt are mostly carried out via human-oriented methods: project
close-out and intermediate meetings, review sessions and personal
communication.
6. Most of designer are not aware about buildability problem as being quality
indicator of their finished projects.
7. Due to the importance of facades finishing material work and since floor beams
are major components of most building in UNRWA projects, the designers and
the construction team should have close co-operatioin to use standard details
where possible with clear specification to achieve ease of construction and
reducing the changing orders.
5.2.8 Summery
According to findings in the case study, the common ineffective recommendation by
the designers compared by the results of the questionnaire is as following:
1. Designer should be involved during impelimintation process.
2. The designers and the other project participants should have close co-
operatioin to use standard details where possible with clear specification to
achieve ease of construction and reducing project time and cost.
3. Peer reviews and feedback systems are the most important tools that should
be applied to achieve high levels of buildability.
4. Develop the feedback system and documentation in such a way to minimize
the buildability problem.
5. Involvement and discussion with end-users in the early stage of design to
identify their requiremtnt and needs.
6. Designer should aim to maximize standadization of items and repetition of
element size to ensure efficient and cost effective.
7. To develop educationand training system to raise the level of buildability
knoledeg within the desginers team.
.
78
Chapter 6 CONCLUSION AND RECOMMENDATIONS
6.1 Introduction The research aims to investigate the buildability during the design stage, which could
improve the project performance as well as the project schedule and increasing the
quality of building during of the operation and maintenance stages. This is achieved
through realizing the following research objectives: the first objective was to
eexplore the buildability concept influencing quality of building design, the second
objective was to identify the factors that causes buildability problem due to
designers, the third objective was to identify the factors that influencing of the design
process, the fourth objective was to explore the project components weighting in
UNRWA projects and the last objective was to study the key faced finishing material
that affecting buildability of building design.
6.2 Conclusion After analyzing and interpreting the questionnaire sections, the researchers found and
concluded the following:
6.2.1 The buildability concept to have a high quality of building design
In this research, analysis of identified buildability concept was done to measure its
influence on the quality of building design. According to findings, it is concluded
that:
1. Site condition should be investigated to avoid subsequent delays.
2. Simplify and standardize construction details.
3. Standardize repeatable components to reduce waste and increase construction
efficiency.
4. Prefabricate building components and/or modularize construction.
5. Reduce area distributed during construction to avoid additional landscaping
costs.
6. Reduce unnecessary design requirements.
79
7. Use methods and materials that allow for ease of reconfiguration, renovation
or deconstruction.
8. Select all material based on the update availability in local marketing.
9. Minimizing the time of underground construction.
10. Coordination of design information (drawings, specification, documentation
and management).
6.2.2 Factors that causes buildability problem due to designers
Analysis of identified buildability problem was done to measure its influence on the
quality of building design. According to findings, it is concluded that education and
training on buildability are not provided to designer, lack of effective management
response, the lessons-learned that arising from maintenance field is not documented,
Figure ( 6-1): The buildability concept to have a high quality of building design
80
lack of buildability review for design, inadequate contractor resource, and inadequate
designer technical knowledge are the most significant problems in buildability.
6.2.3 Factors influencing in the design process Design process is an important stage on the project which influencing the quality of
design. In this study, twenty factors which influence in the design process was
identified. Check that design consider the contractor available resources is the most
important factor that effect the design process, the second important factor is coding
and standards on quality of design, the third factor is sharing the knowledge of other
professionals and teamwork during the design stage, then the forth factor is check
that the designs consider the energy efficient building finally the lowest five factors
that influencing of design process are making design decisions on time, check the
site condition and soil test , check that design information are documented , check
that the designs have a positive environmental impact , and the client is satisfied on
design when all elements of the design are discussed and approved.
6.2.4 Facades finishing material affecting Buildability of building design
Facades finishing material have an important affect on buildability of building
design. In this study twelve items was selected based on repeatable components in
UNRWA projects. The items are affecting on buildability of building design.
According to findings it is concluded that internal tiling finishing material and
external pavement finishing material were given the highest buildability ranking
because of its easy working conditions, precast RC wall and steel works were given
difficult to build ranking as they are mostly fabricated of site. Fair face concrete was
given lower buildability ranking because off the lack of good workmanship to
execute fair face concrete
81
6.3 Recommendation This research is recommended that:
.
It is recommended for designer to adopt the standard checklists that achieve
the coordination of design information.
It is recommended to select materials and methods that allow for ease of
reconfiguration and renovation by advise the designers to integrate
contractor’s available resources and construction knowledge during design
process as an approach to improve quality of building design.
It is recommended to plan for training program for designers to avoid the
buildabulity problem and increase the level of buildability.
It is recommended that the UNRWA is to update design tools and new
technology methods to improve the performance of the designers.
It is recommended to provide data library and report of buildability scores for
different types of UNRWA building projects in Gaza to be used as
benchmarking references.
It is recommended that the UNRWA is to developing a standard checklist and
drawing library of good practical details. The standard checklist considers the
lessons-learned that arising from construction and maintenance filed, where it
is considered as an important factors that causes buildability problem.
6.4 Recommendations for future studies Future research should continue to study the impact of the relationship between the
contractors and the designers during design process.
Further study is required to develop relationships between designer and site staff.
In addition more extensive research can be undertaken using evaluation buildable
design by used the scoring system considering the component weighting that was
identified in this research.
82
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89
Appendix (1)
Questionnaire
Buildability Concept Influencing Quality of Building during
Design Process in UNRWA Projects
استبانه
في مشاريع األنروا علي جودة البناء خالل عملية التصميم " قابلية البناء "أثر
...الكرام الزمالء
أتقدم لكم بالشكر والتقدير لمساھمتكم معنا في تخصيص جزء من وقتكم في ضوء معرفتكم وخبرتكم من أجل التعرف علي . ية في قطاع غزةسمفھوم امكانية البناء للمشاريع الھند
أھداف البحث
للمشروعالتعرف علي مفھوم امكانية البناء من خالل عملية التصميم ومدي أھميتة في تحقيق جوة أفضل. وضع المعايير التي تھدف الي تطوير عملية التصميم من العمل علي ة مساھمة فريق التصميم يالنعرف علي أھم
.للمشاريع الھندسة في قطاع غزة
تعبئة االسنبانة أن الباحث ويأمل بغزة، اإلسالمية الجامعة في المشاريع الھندسية إدارة في الماجستير شھادة لنيل التكميلي البحث ھي الدراسة ستساھمون التي تطوير عملية التصميم من خالل تطبيق مفھوم امكانبة البناء علما ان المعلومات في ھذه الدراسة نتائج تساھم .بكم الخاصة المعلومات بسرية التام االلتزام مع الدراسي، البحث لغرض ھي بھا
Buildability)( تعريف مفھوم امكانية البناءBuildability is the extent to which the design of a building facilitates ease of construction, subject to the overall requirements for the completed building high level of satisfaction.
ال من الرضا مع استكمال تنفيذ المشروع امكانية البناء ھو المدي الذي يعني بسھول تنفيذ التصميم وتحقيق مستوي ع .كما تم تصميمه
للتواصل محمد عبد الغفار عباس \الباحث
0599338786
e-mail [email protected]
نبيل الصوالحي. د \أشراف
2014الجامعة األسالمية غزه
تقبلوا فائق الشكر والتقدير
غزة-الجامعة الإلسالمية
عمادة الدراسات العليا
كلية الھندسة
إدارة مشروعات ھندسة
The Islamic University ‐Gaza
Higher Education Deanship
Faculty of Engineering
Engineering projects Management
90
Questionnaire
Please kindly respond to the following question by ticking ( √ ) the appropriate box, or writing your answer in the space provided.
General information
1. Position of respondent
□ Architect □ Structural Eng
□ Construction Eng □ Maintenance Eng
□ Quantity surveyor
□ Client
□ Others, specify------------
2. Years of experience in the construction industry
□ Less than 5 years
□ 5-10 years
□ 11-15 years
□ 16-20 years
□ More than 21 years
3. Education
□ Diploma
□ B.Sc.
□ M.Sc.
□ Ph.D.
4. The major of your experience
□ Design
□ Construction
□ Maintenance
□ Project management
5. Years of works in organization
□ Less than 2years
□ 2-5years
□ 6-10 years □ More than10 years
6. Term of buildability mainly impact
□ Design stage □ Construction stage
□ Operation and maintenance stage
7. What is the percentage of involvement did the design process have in the establishment of quality of building performance?
? مدي تأثير عملية التصميم في تحقيق جودة المشروع
□ Less than 25%
□ 25-50%
□ 51-75%
□ More than76%
91
Part I: Buildability concept influencing quality of building design
تأثير مفھوم امكانية البناء علي جودة التصميم
Please kindly respond to the following question by ticking ( √ ) the appropriate box, or writing your answer in the space provided.
5 very high important,4 high important,3midum important,2low important, 1very low important
1 Buildability concept 5 4 3 2 1
1.1 Site condition should be investigated to avoid subsequent delays
مراعاة ظروف الموقع لتجنب أي تأخير غير مطلوب
1.2 Simplify and standardize construction details تفاصبل انشائية بسيطة
1.3 Standardize repeatable components to reduce waste and increase
construction efficiency تفاصيل موحدة لجميع العناصر المنكررة لتقلبل الفاقد
1.4 Prefabricate building components and/or modularize construction
استخدام عناصر سابقة التجھيز
1.5 Reduce area distributed during construction to avoid additional
landscaping costs
1.6 Reduce unnecessary design requirements
تقليل العناصر الغير ضرورية في التصميم
1.7 Use methods and materials that allow for ease of reconfiguration,
renovation or deconstruction
ستخدام مواد وطرق تنفيذ تكون قابله للصيانة والنفبذا
1.8 Select all material based on the update availability in local marketing
متوفرة في السوق المحلي استخدام مواد
1.9 Minimizing the time of underground construction
تقيل وقت األعمال المنفذة تحت األرض
1.10 Coordination of design information (drawings, specification
,documentation and management)
تحقيق التواصل في معلومات التصميم
Part II: Factors that causes buildability problem due to designers العوامل التي تعيق المصمم من استخدام امكانية البناء Please kindly respond to the following question by ticking ( √ ) the appropriate box, or writing your answer in the space provided.
5 very high important,4 high important,3midum important,2low important, 1very low important
2 Buildability problem 5 4 3 2 1
2.1 Lack of buildability review of design
ضعف مراجعة التصميم
2.2 Lack of effective management response
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عدم اإلستجابة الفعاله من قبل اإلدارة
2.3 Insufficient and unrealistic constraints of available material
تتعلق بتوفر مواد محليه معوقات
2.4 Inadequate the contractor resource عدم مالئمة مصادر وامكانية المقاول
2.5 Poor communication among design team
ضعف التواصل بين فريق التصميم
2.6 Poor client briefing
عدم وضوح متطلبات التصميم من قبل المالك
2.7 Poor designer briefing
عدم وضوح الفكرة التصميمية لدي المالك من قبل المصم
2.8 Lack of project definition
عدم تحديد طبيعة المشروع
2.9 Inadequate designer technical knowledge
ة للمصممضعف في الخبرة الفني
2.10 Poor specification
مواصفات غير مناسبة
2.11 Unclear details drawing
مخططات تفصيلية غير واضحة
2.12 Design changes
أوامر تغيير علي التصميماحدات
2.13 Insufficient and unrealistic constraints of project time
معوقات غير منطقية تتعلق بوقت المشروع
2.14 Insufficient and unrealistic constraints of project cost
معوقات غير منطقية تتعلق بتكاليف المشروع
2.15 Education and training on buildability are not provided to designer
عدم توفير تدريب كافي للمصمم عن امكانية البناء
2.16 Designer don’t have adequate time to give sufficient attention to
buildability امكانية البناءال يتوفر لدي المصمم الوقت الكافي لالھتمام ومراعاة
2.17 Manager don’t have adequate time to give sufficient attention to
buildability ءال يتوفر لدي اإلدارة الوقت الكافي لالھتمام ومراعاة امكانية البنا
2.18 The lessons-learned that arising from construction field are not documented
خالل التنفيذ للمشروع موقعالعدم توثيق الدروس المستفادة من
2.19 The lessons-learned that arising from maintenance field are not documented
خالل الصيانة للمشروع موقع ال عدم توثيق الدروس المستفادة من
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Part III: Factors that influencing of the design process Please kindly respond to the following question by ticking ( √ ) the appropriate box, or writing your answer in the space provided.
5 very high important,4 high important,3midum important,2low important, 1very low important
3 Factors that influencing of the design process 5 4 3 2 1
3.1 Review designs regularly to ensure that the requirements of the
definitive project brief are met in (the Schedules of areas, room data
sheets, specifications and cost). مراجعة التصاميم بانتظام لضمان تلبية التصمبم لجيع المتطلبات
3.2 Submission of design information that can be readily understood.
تقديم معلومات تصميمبة بمكن فھمھا
3.3 Site condition should be investigated to avoid subsequent delays
التحقق من ظروف الموقع لتجنب التأحير
3.4 Check that the designs are efficient use of space
مراجعة التصميم للتأكد من األستحدام األمثل للمساحات
3.5 Check that the designs are positive environmental impact
مراجعة التصميم من تأثيرة اإليجابي علي البيئة
3.6 Check that the designs are meet security and safety regulations.
التأكد من استيفاء التصميم لجميع معايير السالمة
3.7 Check that the designs are energy efficient buildings
l موفر للطاقة التأكد أن التصميم
3.8 Check that the designs are improvable
التصميم يكون قابل للتطوير في المستقبل
3.9 Check the material that can be easy to maintain and durable
التأكد أن المواد المستحدمة تكون قابلة للصيانة وأكثر فاعلية
3.10 The Client is satisfied on design when all elements of the design are
discussed and approved. المالك بالتصميم وموافقته علي جميع مكونات الصميماقتناع
3.11 Developing standard checklists-completeness of information on
drawings. المخططاتتطوير قائمة لفحص المعلومات عن
3.12 Check the design are consider the contractor resource
التأكد من مراعاة التصميم لالمكانيات المقاول
3.13 Check the site condition and soil test فحص ظروف الموقع والتربه
3.14 Sharing the knowledge of other professionals and teamwork during the
design stage مشاركة المعلومات مع أصحاب الخبرة وفريق التصميم خالل عملية التصميم
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3.15 Effect of code and standards on quality of design
جودة التصميمعلي وحدة القياس العاليمة تأثير
3.16 Effectiveness of lessons-learned programs during design process
فعالية الدروس المستفادة من المشاريع المماثلة خالل عملية التصميم
3.17 Effectiveness of lessons-learned programs during implementation فعالي
ة الدروس المستفادة من المشاريع المماثلة خالل التنفيذ
3.18 Making design decisions on cost مراعاة التصميم للتكاليف
3.19 Making design decisions on time مراعاة التصميم للوقت
3.20 Check the design information are documented
جميع المغلومات التي تتعلق بالتصميم التأكد من توثيق
Part IV: Project component weighting مكونات المشروع Based in your experience, Please give your opinion as the relative important weighting (percentage term %) of the following
component in respective of buildability and cost..
4 Component Suggested
weighting%
Remarks if you have
4.1 Envelop System
(exterior and interior wall, foundation, Slab, roof)
%
4.2 Structural Frame System %
4.3 Slab and roof system %
4.4 Vertical transportation structures, such as
stairs, lifts, ramps etc
%
4.5 Site specific factors
(Retaining wall, leveling, Others)
%
4.6 Building finishes
Doors, windows, painting, tilling, others)
%
4.7 Services
(Plumbing & Internal drainage Electric power &
lighting, Others)
%
Total 100%
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Part V: Facades finishing material affecting buildability of building design تأثير مواد التشطيب علي امكانية البناء في تصميم المبنيمدي
Please kindly respond to the following question by ticking ( √ ) the appreciate box, or writing your answer in the space provided.
5 very easy buildable,4 easy buildable, 3`buildable, 2difficult to build , 1 very difficult to build
A External facades finishing material 5 4 3 2 1 A1 Fair face concrete
A2 Traditional plaster and paint
A3 Granite , stonework, ceramic
A4 Cladding metal
A5 Glass work
A6 Steel roof slab
A7 Concrete staircase (internal)
A8 Steel staircase for (external)
A9 Precast RC wall with pre-installed windows and finishes
A10 Aluminum curtain wall
A11 Internal tiling sizing for easy to maintain and durable
A12 External pavement finishing material easy to maintain and durable
B Roof /Slap covering 5 4 3 2 1 B1 Composite type slap
B2 Waterproofing membrane with protective layer
B3 Liquid applied waterproofing with protective layer
B4 Horizontal or vertical Expansions joint
Thank you very much for your participation in this survey