structural timber estimating guide 2016 · 2017-11-09 · structural timber estimatig guide 2016...

Structural timber estimating guide 2016

STRUCTURALTIMBER ASSOCIATIONBuilding solutions in timber

STRUCTURAL TIMBER ESTIMATING GUIDE 20162

Preface

In 2011 the Structural Timber Association (then the UKTFA) set up a Think Tank to ensure two way communication between the structural timber manufacturing industry and the UK construction sector. On the think tank was clients, contractors, architects, engineers, housebuilders etc. One member, Ian Dacre of Rider Levett Bucknall a Quantity Surveyor, pointed out that many QS’s, although consider structural timber, face challenges in sourcing cost and estimating information when preparing budgets and costs for clients. The usual industry sources of cost and pricing information do not contain structural timber elements, as such are not promoted through these documents.

This was a ‘light bulb’ moment for the STA in their ambition to increase the level of knowledge of the products and services its members offer and in turn increase their market share. The idea of a Structural Timber Estimating Guide was born and Ian Dacre was commissioned to produce this document which will be the first of a series of guides representing the structural timber industry.

We are indebted to Ian for his patience, diligence and professionalism in putting this guide together along with Alex Goodfellow of Stewart Milne Timber Systems and the STA Commercial Committee, in particular John Capper of Oakworth Homes, and the other STA manufacturer members who have participated by providing information. Their work has resulted in a document which will assist the construction industry at large as it moves to use more structural timber for economic, environmental, quality and social reasons.

Andrew Carpenter, Chief Executive Structural Timber Association

Contents

Preface 2

Introduction 4

About this guide 5

Future issues of the guide 6

The structural timber frame industry 7

How to use the estimates within this guide 8

Summary of worked examples 9

Apartments Summary of apartments specification 10 Apartments elevations and floor plans 11 Apartments worked example 12

Housing Summary of housing specification 14 Housing elevations and floor plans 15 Housing worked examples 16

Hotel Summary of hotel specification 18 Hotel elevations and floor plans 19 Hotel worked example 20

3

Information on fire risk mitigation 22

Costs associated with fire risk mitigation 23

Benefits of building in timber frame 24

Other types of structural timber construction 26

Glulam (engineered wood) 26

Cross laminated timber (CLT) 27

Structural insulated panels (SIP) 28

Oak frame 29

Contributors to this guide 30

Design flexibility 31

Photography for this guide courtesy of Oakworth Homes and Stewart Milne Timber Systems


IntroductionThere are many pricing books and estimating guides available in the construction industry market place giving costs for a multitude of products, materials and systems. They are an invaluable tool and used by many construction professionals, contractors, clients, suppliers, manufacturers and the like.

Without these pricing books and guides used for estimating and benchmarking the industry supply chain would have difficulty efficiently providing budgets, estimates, cost plans and cash flows for the many organisations that operate within the construction sector.

At present the cost and estimating information for structural timber is in short supply, with many members of the supply chain resorting to speaking to the structural timber industry seeking prices and obtaining budget quotes. This is the best source of technical and pricing information but it can be wasteful of resource and time for these organisations when cost managers or quantity surveyors can use indicative rates, prices and costs to arrive at an evaluation sufficient for cost planning and budgeting. This guide is not a replacement for speaking to the professionals in the structural timber industry but a tool to assist in the generation of an overall project cost or budget to those in the industry preparing same.

We also hope the guide will promote further the increasing use of timber frame and structural timber by demonstrating the cost information is readily available and understandable, and over time, will be able to benchmark and compare to other building structural components. There are price books available covering other structural elements such as concrete, steel and masonry and the permutations of all three, with the industry understanding the interrelationships of these components. We believe this guide will be used early in the budget and estimating stages to include for timber at the outset, rather than possibly including other materials and then converting to timber later in the construction journey.

There are differences, generally, between the way a Quantity Surveyor and timber frame manufacturer estimates the structure of a typical building. A Quantity Surveyor evaluates the individual building components following elemental headings: external walls, frame, roof, internal walls etc whereas the timber frame manufacturer values the elements as one all-embracing, composite item.

Steel is quantified and evaluated by the tonnage for beams, columns, trusses, fittings etc and broken down into those components. Concrete frames are evaluated by the concrete, reinforcement, formwork etc. again split into beams, columns, walls and floors. Masonry is evaluated using a superficial face area of the material, or walls or columns.

A structural timber frame is usually offered by the timber frame industry as an inclusive single unit / entity incorporating the specification and structural components desired by the client. What is attempted by this guide is to break down the single unit / entity into more understandable and measurable components for external walls, floors, internal walls etc. This is in order to provide a financial model for structural timber that is akin to the other structural components.

As you may be aware this is the first attempt to produce such a guide and we are indebted to those members of the Structural Timber Association who have given their time in assisting with the preparation. We have focused at this stage on the traditional timber frame but future issues will also include many other structural timber components (SIPS, CLT, Glulam, oak frames and the like). We have included brief details of these components later in the guide.

If any users of the guide have any observations for the future we would be grateful to hear your views and comments so that we may progress and develop the guide in the coming years.

Ian Dacre

Partner, Rider Levett BucknallT: 07920 273308E: [email protected]

This guide is a tool designed to assist quantity surveyors in the generation of an overall project cost or budget

4

About this guideThere are differences between the way quantity surveyors / cost managers and the structural timber industry estimate or cost a project. The industry tends to provide an all-inclusive service and price that incorporates the design, manufacture, delivery and installation of the structural building.

This guide uses the methods utilised by surveyors and cost managers and aims to allow evaluation of the specification in both an elemental and inclusive way that will enable comparison with other forms of construction. The guide also aims to explain the benefits and value that can be brought to a project from the structural timber specifications included.

In compiling this document many people and organisations associated with the Structural Timber Association have been involved, as noted below and listed on page 30. These are the companies who provided the invaluable pricing information and without their input the guide could not have been prepared. If you wish to contact them direct for further information or specification, technical or pricing information they will be only too happy to help.

In particular we need to thank Oakworth Homes Ltd and Stewart Milne Timber Systems, John Capper and Alex Goodfellow, respectively, who provided the detailed technical information and guidance in the compilation of the specification elements. Thanks must also go to Whitbread and Stewart Milne Homes for allowing us to use the example projects that are noted within the guide.

A final thank you needs to be levied at Andrew Carpenter, Chief Executive of the STA, for having faith in what was an outline idea a few years ago and his vision in seeing the benefits of the guide and allowing its preparation. The team who collectively prepared the guide include:

Ian Dacre Rider Levett Bucknall UK Ltd

Alex Goodfellow Stewart Milne Timber Systems

John Capper Oakworth Homes Ltd

Martin Milner Milner Associates

5


Future issues of the guideThis estimating guide is intended to be the first of a series to focus on structural timber off-site construction methods. It concentrates on the most commonly used timber method; however the follow-on guides will include information on the following types of structural timber solutions.

These guides, together with the information and assistance of member companies of the STA will assist cost consultants to select the method of construction used in any project. This will enable projects to be estimated, costed and specified for timber solutions - and compared to other forms of construction.

Cross laminated timber (CLT) panels Solid wood panels delivered as walls, floors and roofs where follow-on trades install insulation outside the critical build path, install services, drylining (as an option), fenestration and internal works.

Closed-panel timber frame Enclosed insulated structural timber frame panels with options to include insulation, vapour control and airtightness layers, windows, doors and services.

Structural insulated panels (SIP) As closed panel, with composite high performance insulation injected during the manufacture process.

Pre-insulated timber frame Structural open panel with insulation installed in the factory with additional options to include vapour control and airtightness layers.

Engineered wood (Glulam, LVL, Kerto and the like) Glue laminated timber, commonly used as elements within another structural timber building or steel / concrete building to achieve large spans and feature members for large section beams and columns.

Open-panel timber frame Timber frame pre-fabricated structural wall and floor panels where follow-on trades install insulation, services, drylining, external fenestration and internal works.

6

The structural timber frame industryThe UK timber frame industry has provided housebuilders, developers, housing associations, contractors in the commercial sector and self-build sector with an integrated design, manufacture and on-site erection service for over 50 years.

Timber frame is one of the most technologically advanced and sustainable forms of construction available in the 21st century. It ensures a high quality product, can reduce overall build costs and shortens the duration of build programmes. 70% of the developed world’s population live in timber frame houses. These include many in the USA, Canada, Scandinavia, Europe, Australia and Japan.

In the UK, timber frame is the fastest growing form of construction, with the current share of 24.6% of all new homes in the UK, which is expected to continue to grow over the coming years. Structural timber is already a favoured form of construction in a number of commercial solutions such as medium rise hotels, student accommodation, education buildings, self-build developments and many others

As the industry has adapted to changing market demands it is driven by intelligent design for manufacture and assembly principles and provides excellent integrated off-site construction solutions to the marketplace.

7


How to use the estimates within this guideThe estimating guide is intended to provide assistance for budget preparation, cost planning / management and benchmarking exercises. It is not intended to be used as a tool for tendering and negotiation of contracts. All the costs, prices and rates included within the guide have been provided by the structural timber industry and tabulated by the author Ian Dacre of Rider Levett Bucknall.

In order to be accurate and in line with other price books in setting a baseline, the costs included are set at the 1st quarter of 2016. The pricing and rates do not include any risk or contingency allowances.

The costs are based on three separate projects constructed in timber frame. For illustration and comparison purposes the projects are located in central England, and are assumed to be on relatively flat ground and with reasonable access from a major ‘A’ road.

These three worked examples provide a detailed breakdown of the elements included in the price for a structural timber frame. For each example we have included plan and elevation drawings to give an indication of the scale, design and arrangement of the buildings.

For ease we’ve provided a summary specification of all services, materials, plant and labour that is included within the costs for the three model projects. We have also included within the costing tables the commonly selected extras and options required by clients and specifiers. Also included is a typical summary of all elements and services deemed as exclusions and not included or provided by the timber frame supplier.

8

The model projects are as follows;

• Apartmentblock,threestorey • Housingdevelopment,twostorey 12 units 100 detached and semi-detached houses

• Hotel,twostorey 40 en-suite bedrooms, with reception area

Within this guide it is assumed that the main contractor will provide all site welfare, any storage and security for the structural timber frame contractors and labour attendances, together with any crane mats / supports to comply with the overall health and safety requirements of the site. It is also assumed that all foundations, under-building and scaffolding will be provided by the main contractor.

Other specific exclusions are the main contractors’ overheads, profit and any other on-costs associated with the project requirements and remaining costs to fully complete the project.

Summary of worked examplesThe table below summarises the range of rates received from various timber frame suppliers for the model examples. The model example cost is the mean rate from the prices received.

NOTE: The rates above do not include the optional items within each of the model examples.

9

Traditional timber frame Low Model Example High

Base cost ranges £ / m2

Apartment block - 12 units over three floors £123.28 £165.58 £189.93

Detached house £119.00 £137.03 £155.60

Semi-detached house £120.81 £155.76 £178.87

Hotel - 40 bedrooms over two storeys £116.19 £119.20 £130.00


The rates shown in the table below include for the following elements and specification: design, manufacture and delivery of the timber frame, including plant and site labour to off-load and erect, with internal safety decking / working platforms / fall arrest systems.

Summary of apartments specification

10

External walls• 140mmwidetimberstudpanelswith9mmOSBand low emissivity reflective breather paper• 140mmwidetimbersoleplateshead-binders,andrails• Timberframewall-tiestosuit50mmcavity• Cavitybarrierstosuit50mmcavity• Timbernogginsforservices

Separate rates are also shown for the following elements:• Sitefittedwoolinsulationbetweenstuds,toachievea U-value of 0.27W/m2K• FactoryfittedPIRinsulationbetweenstuds,toachievea U-value of 0.20W/m2K• ExternalwallU-valuesareavailableintimberframefrom 0.27 to 0.10 and beyond

Party walls• 89mmwidetimberstudpanelswith9mmOSBtocavityface• 89mmwidetimbersoleplateshead-binders,andrails• Fullfillcavityinsulation,withpolythenesleevedcavity barriers to seal edges of party wall cavity

Separate rates are also shown for the following elements:• Sitefittedwoolinsulationbetweenstuds

Internal non-load bearing walls • 89mmwidetimberstudpanelswithonerowmid-height noggin• 89mmwidetimbersoleplateshead-binders,andrails

Separate rates are also shown for the following elements• 50mmacousticinsulationbetweenstuds

Roof• Rooftrusses,includingvalleysetsandin-filltimberforhipped-ends,andbracing• 89mmwidetimberspandrelpanelswith9mmOSBandbreatherpaper• 89mmwidetimbergableladders• Trussshoesandallotherassociatedironmongery• 300mmwidevalleyboardandsupportingtimbernoggins• Partywallspandrelpanels,pre-cladwithtwolayers12.5mmplasterboardandpolytheneprotection

Internal loadbearing walls• 89mmwidetimberstudpanelswith9mmOSB• 89mmwidetimbersoleplateshead-binders,andrails

Separate rates are also shown for the following elements:• 50mmacousticinsulationbetweenstuds

Intermediate floor• 15mmOSBstructuraldecking• Nominal240mmdeeptimberI-Joists,including trimmers and beams to form upper floor• Joisthangersandallotherassociatedironmongery

Separate rates are also shown for the following elements:• Floatingfloorbuild-upincorporating: - 22mm P5 chipboard flooring - 19mm acoustic plank - 75mm acoustic timber battens - 25mm acoustic insulation between battens - 75mm flanking strip to flooring perimeter - Rip-liner board to flooring perimeter

Apartments elevations and floor plans

11

The following items are excluded from the rates shown• Foundationandallgroundfloorworksuptofinished floor / DPC level• Roofingfeltandtilebattens,fasciaandsoffit• Externalcladding,doorsandwindows• PlasterboardandVCL’s - Party walls will require two layers 15mm board (or 1 x 12.5mm + 1 x 19mm) to achieve the fire and acoustic performance - All external and load-bearing walls (top floor will require two layers 12.5mm plasterboard to achieve 60min fire performance - Ceiling of separating floors will require two layer 15mm fireline plasterboard on 16mm resilient bars to achieve fire and acoustic performance

• Acousticandthermalinsulationtomidfloorandroof ceilings - Separating floors will require minimum 100mm mineral fibre insulation between the joists to achieve acoustic performance• Stairflightsandhandrail - Timber stairs within apartments will require fire treatment, and increased specification of stringers, treads and risers to achieve fire performance• FirstandsecondfixplumbingandM&Eservices• Scaffolding• Sitesecurityandwelfarefacilities• Wastedisposal

Elevation

Ground floor plan


Apartments worked example

12

Apartment block of twelve units over three floors with a central stair core. Gross internal floor area = 889m2

Traditional timber frame

Preliminaries

Quantity Unit Rate £ Total £ Cost / m2

Design, manufacturing set up 889 m2 12.25 10,890.25

Deliver to site 889 m2 5.21 4,631.69

Supply of materials

External walls, 38x140 mm load bearing, 9mm OSB, 2.4m high (GROUND FLOOR) 76 m 50.86 3,865.36

76 m 45.01 3,420.76

76 m 45.01 3,420.76

External walls, 38x89 mm load bearing, 9mm OSB, spandral panels

2 m2 19.06 38.12

Party walls, 38x89 mm load bearing, 9mm OSB, 2.4m high (GROUND FLOOR)

107 m 33.78 3,614.46

Party walls, 38x89 mm load bearing, 9mm OSB, 2.4m high (FIRST FLOOR) 107 m 32.24 3,449.68

Party walls, 38x89 mm load bearing, 9mm OSB, 2.4m high (SECOND FLOOR)

107 m 32.24 3,449.68

Party walls, 38x89 mm load bearing, 9mm OSB, spandral panels 194 m2 19.96 3,872.24

Internal walls, 38x89mm, load bearing, 9mm OSB, 2.4m high (GROUND FLOOR) 57 m 34.83 1,985.31

Internal walls, 38x89mm, load bearing, 9mm OSB, 2.4m high (FIRST FLOOR) 57 m 32.31 1,841.67

Internal walls, 38x89mm, non load bearing, 2.4m high (GROUND FLOOR) 43 m 29.17 1,254.31

Internal walls, 38x89mm, non load bearing, 2.4m high (FIRST FLOOR)

41 m 28.16 1,154.56

Internal walls, 38x89mm, non load bearing, 2.4m high (SECOND FLOOR) 97 m 28.16 2,731.52

Structural racking 1 item 4,940.54 4,940.54

Roof trussed rafters including straps and bracing (MEASURED ON PLAN) 342 m2 36.03 12,322.26

External walls, 38x140 mm load bearing, 9mm OSB, 2.4m high (FIRST FLOOR)

External walls, 38x140 mm load bearing, 9mm OSB, 2.4m high (SECOND FLOOR)

13


Extra over items


Other optional items (to be included if required)

Fall arrest 1 item 1,214.50 1,214.50

Steelwork support may be required but this depends on the specifics of each design - structural engineering advice should be sought

Extra-over for external wall insulation for 110 PIR foil-faced insulation, 0.20 u-value in typical wall make-up (SUPPLY AND FACTORY FIT)

432 m2 11.30 4,881.60

Craneage 1 item 6,749.40 6,749.40

Erection of frame and associated items 1 item 23,776.50 23,776.50

Gable ladder to roof 4 m 7.75 31.00

Upper floors, 15mm OSB decking, 240mm deep nominal floor joists, including stair trimmers and noggins

614 m2 28.90 17,744.60

614 m2 35.44 21,760.16

Wall ties stainless steel, approx quantity, 4.5nr / m2 (SUPPLY ONLY)

1953 nr 0.18 351.54

Anchor / holding down straps, pre-bent stainless steel 166 nr 2.01 333.66

432 m2 4.80 2,073.60

147,197.14 165.58

Reflective breather membrane 432 m2 2.33 1,006.56

Party wall insulation, 60mm between leafs (SUPPLY AND FIT) 770 m2 5.11 3,934.70

Internal walls, 50mm thick acoustic insulation (SUPPLY AND FIT)

193 m2 4.36 841.48

Services noggins - 50 per plot (SUPPLY ONLY) 1 item 171.00 171.00

Plasterboard noggins (SUPPLY ONLY) 1 item 552.86 552.86

Fire socks 1 item 986.91 986.91

Total base cost supply and erect for the timber frame

153,293.24 172.43Total cost supply and erect for the timber frame

Floating floor, 22mm T&G V313 MR chipboard flooring, 19mm plank, 75mm acoustic battens, 25mm acoustic insulation quilt, 75mm flanking strip and rip-liner board to perimeter

External walls, insulation to Building Regulations standard, 140mm thick 0.040 lambda value glasswool (SUPPLY AND FIT)


Summary of housing specificationThe rates shown in the tables include for the following elements and specification: design, manufacture and delivery of the timber frame, including plant and site labour to off-load and erect, with internal safety decking / working platforms / fall arrest systems.

External walls• 140mmwidetimberstudpanelswith9mmOSBandlow emissivity reflective breather paper• 140mmwidetimbersoleplateshead-binders,andrails• Timberframewall-tiestosuit50mmcavity• Cavitybarrierstosuit50mmcavity• Timbernogginsforservices

Separate rates are also shown for the following elements:• Sitefittedwoolinsulationbetweenstuds,toachievea U-Valueof0.27W/m2K• FactoryfittedPIRinsulationbetweenstuds,toachievea U-Valueof0.20W/m2K• ExternalwallU-valuesareavailableintimberframefrom 0.27 to 0.10 and beyond

Party walls• 89mmwidetimberstudpanelswith9mmOSBtocavityface• 89mmwidetimbersoleplateshead-binders,andrails• Fullfillcavityinsulation,withpolythenesleevedcavity barriers to seal edges of party wall cavity

Separate rates are also shown for the following elements:• Sitefittedwoolinsulationbetweenstuds

Internal non-load bearing walls • 89mmwidetimberstudpanelswithonerowmid-heightnoggin• 89mmwidetimbersoleplateshead-binders,andrails


Intermediate floor• 22mmpeel-cleanP5chipboardflooring• Nominal240mmdeeptimberI-Joists,includingtrimmers and beams to form upper floor• Joisthangersandallotherassociatedironmongery.


Separate rates are also shown for the following elements:• 50mmacousticinsulationbetweenstuds

Roof• Rooftrusses,includingvalleysetsandin-filltimberfor hipped-ends, and bracing• 89mmwidetimberspandrelpanelswith9mmOSBand breather paper• 89mmwidetimbergableladders• Trussshoesandallotherassociatedironmongery• 300mmwidevalleyboardandsupportingtimbernoggins• Partywallspandrelpanels,pre-cladwithtwolayers12.5mm plasterboard and polythene protection

The following items are excluded from the rates shown• Foundationandallgroundfloorworksuptofinished floor / DPC level• Roofingfeltandtilebattens,fasciaandsoffit• Externalcladding,doorsandwindows• PlasterboardandVCL’s - Party walls will require two layers 15mm board (or 1x12.5mm + 1x19mm) to achieve the fire and acoustic performance

• Acousticandthermalinsulationtomidfloorandroofceilings• Stairflightsandhandrail• FirstandsecondfixplumbingandM&Eservices• Scaffolding• Sitesecurityandwelfarefacilities• Wastedisposal

LIVING ROOM

UTILITY

KITCHEN/DINING

WC

HALL

leaddoor

BATHROOM

LANDING

MASTER BEDROOM

W

BEDROOM 3BEDROOM 2

WALK INWARD

LIVING ROOM

UTILITY

KITCHEN/DINING

WC

HALL

leaddoor

BATHROOM

LANDING

MASTER BEDROOM

W

BEDROOM 3BEDROOM 2

WALK INWARD

Tile Vent

40° 40°

EJEJ

15

Housing elevations and floor plans

House type F (detached)

House type B (semi-detached)

40°

Tile Vent

40° 40°40°

EJ

UTILITY

WC

GARAGE

ST

KITCHEN/ DINING/ FAMILY

LIVING ROOM

HALL

leaddoor

GUEST BEDROOM

BATHROOM

BEDROOM 4

MASTER BEDROOM

EN-SUITE

BEDROOM 3

LANDING

W

ST

W

EN-SUITE

OPTIONAL WARDROBEwith 1212mm sliding door

(OPTIONALVANITY UNIT)

UTILITY

WC

GARAGE

ST

KITCHEN/ DINING/ FAMILY

LIVING ROOM

HALL

leaddoor

GUEST BEDROOM

BATHROOM

BEDROOM 4

MASTER BEDROOM

EN-SUITE

BEDROOM 3

LANDING

W

ST

W

EN-SUITE

OPTIONAL WARDROBEwith 1212mm sliding door

(OPTIONALVANITY UNIT)

First floor

Ground floor First floor

Ground floor


House type F (detached). Gross Internal Floor Area (including garage area) = 126m2

Housing worked example - detached


Preliminaries


Design, manufacturing set up 126 m2 5.94 748.44

Deliver to site 126 m2 5.03 633.78

Supply of materials

External walls, 38x140 mm load bearing, 9mm OSB, 2.4m high 66 m 46.01 3,036.66

23 m2 20.05 461.15

13 m 30.79 400.27

Internal walls, 38x89mm, non load bearing, 2.4m high 50 m 29.08 1,454.00

Structural racking 1 item 165.54 165.54

Roof trussed rafters inc straps and bracing (MEASURED ON PLAN) 81 m2 19.22 1,556.82

Extra over items

Craneage 1 item 1,091.70 1,091.70



Upper floors, 22mm Peelclean T&G chipboard, 240mm nominal floor joists, including stair trimmers and noggins

67 m2 32.45 2,174.15

Wall ties stainless steel - approx quantity, 4.5nr / m2 (SUPPLY ONLY) 738 nr 0.17 125.46

Anchor / holding down straps - pre-bent stainless steel 72 nr 2.02 145.44

141 m2 4.80 676.80

Reflective breather membrane 141 m2 2.21 311.61

Internal walls, 50mm thick acoustic insulation (SUPPLY AND FIT) 72 m2 4.36 313.92

Services noggins - 50 per plot (SUPPLY AND FIT) 1 item 26.67 26.67



Fall arrest 1 item 264.40 264.40

Extra-over for external wall insulation for 110 PIR foil-faced insulation, 0.20 u-value in typical wall make up (SUPPLY AND FACTORY FIT)

141 m2 11.30 1,593.30


External walls, 38x89 mm load bearing, 9mm OSB, spandral panel

Internal walls, 38x89mm, load bearing, 9mm OSB, 2.4m high



17,265.54 137.03Total base cost supply and erect for the timber frame


17

House type B (semi-detached). Gross Internal Floor Area = 84m2

Housing worked example - semi-detached


Preliminaries


Design, manufacturing set up 84 m2 6.61 555.24

Deliver to site 84 m2 7.03 590.52

Supply of materials

External walls, 38x140 mm load bearing, 9mm OSB, 2.4m high 40 m 45.55 1,822.00

13 m2 19.98 259.74

13 m 35.36 459.68

Internal walls, 38x89mm, non load bearing, 2.4m high 23 m 29.19 671.37

Structural racking 1 item 193.92 193.92

Roof trussed rafters inc straps and bracing (MEASURED ON PLAN) 53 m2 19.93 1,056.29

Extra over items

Craneage 1 item 1,091.70 1,091.70



Upper floors, 22mm Peelclean T&G chipboard, 240mm nominal floor joists, including stair trimmers and noggins

44 m2 32.62 1,435.28

Wall ties stainless steel - approx quantity, 4.5nr / m2 (SUPPLY ONLY) 428 nr 0.17 72.76

Anchor / holding down straps - pre-bent stainless steel 42 nr 2.02 84.84

82 m2 4.80 393.60

Reflective breather membrane 82 m2 2.21 181.22

Party wall insulation, 60mm between leafs (SUPPLY AND FIT) 41 m2 5.11 209.51

Internal walls, 50mm thick acoustic insulation (SUPPLY AND FIT) 28 m2 4.36 122.08

Services noggins - 50 per plot (SUPPLY AND FIT) 1 item 26.67 26.67



Fall arrest 1 item 264.40 264.40

Extra-over for external wall insulation for 110 PIR foil-faced insulation, 0.20 u-value in typical wall make up (SUPPLY AND FACTORY FIT)

82 m2 11.30 926.60


External walls, 38x89 mm load bearing, 9mm OSB, spandral panel

Party walls, 38x89 mm load bearing, 9mm OSB, 2.4m high 17 m 32.41 550.97

11 m2 18.85 207.35Party walls, 38x89 mm load bearing, 9mm OSB, spandral panel

Internal walls, 38x89mm, load bearing, 9mm OSB, 2.4m high






External walls• 140mmwidetimberstudpanelswith9mmOSBandlow emissivity reflective breather paper• 140mmwidetimbersoleplateshead-binders,andrails• Timberframewall-tiestosuit50mmcavity• Cavitybarrierstosuit50mmcavity• Timbernogginsforservices

Separate rates are also shown for the following elements:• Sitefittedwoolinsulationbetweenstuds,with25mm PIR to internal face of studs and 25x50mm vertical battens toachieveaU-Valueof0.15W/m2K• ExternalwallU-valuesareavailableintimberframefrom 0.27 to 0.10 and beyond


Internal non-load bearing walls • 63mmwidetimberstudpanelswithonerowmid-height noggin• 63mmwidetimbersoleplateshead-binders,andrails

Intermediate floor• 18mmOSBstructuraldecking• Nominal240mmdeepsolidtimber(140mmdeepovercorridors),includingtrimmersandbeamstoformupperfloor• Joisthangersandallotherassociatedironmongery

Roof• Rooftrusses,includingvalleysetsandin-filltimberforhipped-ends,andbracing• 89mmwidetimberspandrelpanelswith9mmOSBandbreatherpaper• 89mmwidetimbergableladders• Trussshoesandallotherassociatedironmongery• 300mmwidevalleyboardandsupportingtimbernoggins


Separate rates are also shown for the following elements:• 90mminsulationbetweenstuds

The rates shown in the tables include for the following elements and specification: design, manufacture and delivery of the timber frame, including plant and site labour to off-load and erect, with internal safety decking / working platforms / fall arrest systems.

Summary of hotel specification

19

Hotel elevations and floor plans

The following items are excluded from the rates shown• Foundationandallgroundfloorworksuptofinished floor / DPC level• Roofingfeltandtilebattens,fasciaandsoffit• Externalcladding,doorsandwindows• PlasterboardandVCL’stwolayers12.5mmplasterboardto achieve 60min fire performance. - Internal Bedroom to Bedroom and Bedroom to Corridor walls will generally require two layers 15mm soundblock plasterboard on resilient bars. - Ceiling of separating floors will require 1x12.5mm + 1x19mm plasterboard layers on 16mm resilient bars to achieve fire and acoustic performance• Separatingfloorbuild-up

• Acousticandthermalinsulationtomidfloorandroof ceilings - Separating floors will require min 100mm mineral fibre insulation between the joists to achieve acoustic performance• Stairflightsandhandrail - Timber stairs within hotels will require fire treatment, and increased specification of stringers, treads and risers to achieve fire performance.• FirstandsecondfixplumbingandM&Eservices• Scaffolding• Sitesecurityandwelfarefacilities• Wastedisposal

Elevation

Ground floor plan


Premier Inn of 40 bedrooms over two storeys, including reception, ancillary space and circulation. Gross internal floor area = 1,216m2

Hotel worked example


Preliminaries


Design, manufacturing set up 1216 m2 10.14 12,330.24

Deliver to site 1216 m2 3.51 4,268.16

Supply of materials

External walls, 38x140 mm load bearing, 9mm OSB, 150 wide 2000 guage embossed polythene dpc, 2.4m high (GROUND FLOOR)

125 m 48.65 6,081.25

118 m 43.95 5,186.10

25 m2 17.43 435.75

Internal walls, 38x90mm, load bearing, 9mm OSB, 2.4m high (GROUND FLOOR)

232 m 33.98 7,883.36

Internal walls, 38x90mm, load bearing, 9mm OSB, 2.4m high (FIRST FLOOR)

192 m 32.09 6,161.28

Internal walls, 38x90mm, load bearing, 9mm OSB, spandral panels 46 m2 10.60 487.60

Internal walls, 38x63mm, non load bearing, 2.4m high (GROUND FLOOR)

95 m 22.37 2,125.15

Internal walls, 38x63mm, non load bearing, 2.4m high (FIRST FLOOR) 98 m 21.92 2,148.16

Structural racking 1 item 2,951.26 2,951.26

Roof trussed rafters including straps and bracing (MEASURED ON PLAN) 748 m2 25.73 19,246.04

Extra over items

Craneage 1 item 7,208.15 7,208.15



Timber joists, size 50x225mm at 400 ccs, bracing / blocking pieces, 18mm OSB 3 decking, generally spanning between 3.5m and 4.0m

592 m2 34.14 20,210.88

Wall ties stainless steel, to suit 50mm cavity, approx quantity, 4.5 nr / m2, (SUPPLY ONLY) 2394 nr 0.17 406.98

Anchor / holding down straps and all associated fixings 1 item 169.36 169.36

External walls, 38x140 mm load bearing, 9mm OSB, 2.4m high (FIRST FLOOR)

External walls, 38x89 mm load bearing, 9mm OSB, 2.4m high - (ROOF SPANDREL PANELS)

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Extra over items...cont/



Fall arrest 1 item 1,367.00 1,367.00


External walls, 0.032 lambda glasswool insulation, 140mm thick, between studs (SUPPLY AND FIT) 507 m2 10.10 5,120.70

External walls, Xtratherm thin-R XT/TF zero ODP rigid insulation with 25x50 vertical battens, 25mm thick, over studs (SUPPLY AND FIT)

507 m2 6.68 3,386.76

Reflective breather membrane 507 m2 2.76 1,399.32

Internal walls, 0.040 lambda glasswool insulation, 90mm thick (SUPPLY AND FIT) 1061 m2 3.80 4,031.80

Internal walls, 50mm thick acoustic insulation (SUPPLY AND FIT)

392 m2 4.36 1,709.12

Services noggins (SUPPLY ONLY) 1 item 601.00 601.00






Information on fire risk mitigationAll projects in the UK regardless of construction materials and methods are to comply with the Construction and Design Management Regulations (CDM). CDM 2015 clause 29 requires that suitable and sufficient steps must be taken to prevent, so far as is reasonably practicable, the risk of injury to a person, during the carrying out of construction work, arising from fire.

The HSE have guidance (HSG168) on Fire Safety in Construction which requests that fire safety is required both on the site and also to persons in neighbouring properties outside the site boundary; the CDM regulations and HSG168 are for all building materials and forms of construction.

The Structural Timber Association (STA) has, in conjunction with the Fire Service, HSE and insurance bodies, produced a set of guidance on fire safety during construction for structural timber buildings. STA members follow what is called Site Safe, which is a mandatory membership compliance to support the Principal Designer and Principal Contractor in fire safety during construction.

The STA member will provide the appropriate persons involved with the project access to on-site fire safety guidance (STA 16 Steps, plus Advice Notes)andriskmitigationguidanceonfirespreadtopropertiesoutsidethesiteboundary(STASeparationGuidance).

Structural timber buildings will need to be assessed for the fire risk for which the Principal Designer refers to the STA guidance and selects either the following in the tender process:

1) Full fire risk assessment for the project to cover outside the boundary fire spread risk mitigation, which may be compliance with the STA separation guidance or a bespoke fire engineering approach from a specialist member of the design team.

2) The site has been assessed in the design process to have a fire spread risk and as a result fire risk mitigation is required, which shall be priced accordingly. Options for the fire risk mitigation are to be presented by the supply chain in the tender process, with clear indication as to the method of assessment; be it from the STA guidance or bespoke fire engineering assessment.

For option 2 additional costs may be incurred as the contractor covers the commercial fire risk. In addition, a higher variation of tender costs may occur if non STA members are invited to tender who will not be under the Site Safe conditions, which is there to safeguard the client.

NOTE: It is not acceptable under CDM 2015 and HSG168 for the principal designer to issue a tender that has not been assessed initially for an outside the site boundary fire risk assessment.

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Careful site planning and sequencing of dwelling construction can help reduce any potential cost meaning that, unless the project is within a heavily built up location, it is possible to minimise costs of complying with CDM requirements. In areas where the new building is to be in a densely built location, careful planning and communication with any Structural Timber Association member company can help you understand your options to ensure you are planning a safe, cost effective project.

Housing Nocostimplicationsasbelow600m2 threshold

Apartments

Nocostimplicationon typical housing development site

1% to 2% uplift if within 18m of an occupied building

3% to 5% uplift if within 8m of an occupied building

Hotel

Nocostimplicationontypicalnew-buildbrownfieldsite

1% to 2% uplift if gable within 13m of an occupied building

3% to 5% uplift if elevation within 18m of an occupied building

3% to 5% uplift if gable within 7m of an occupied building

5% to 10% uplift if elevation within 7m of an occupied building

Costs associated with fire risk mitigation For the example building types included in this document, the follow guide provides outline cost uplift on top of the base costs associated with fire mitigation for separation distances:


Benefits of building in timber frameTimber frame is a load-bearing, structurally engineered building solution utilising structural timber and sheathing materials. A structural timber frame can be used in most places a masonry, steel or concrete solution is found, with the typical exception of works below ground. Building in structural timber delivers a whole host of advantages, in both the long and short term. There are many advantages, credentials and considerations.

Structural timber solutions offer

• Fabric-firstapproachtolowcarbonconstructionandthermalperformance

• Singlepointresponsibilityforstructuralintegrity

• Wholeframesolutionsforwalls,floorsandroofsfromonecompany

• HealthandSafetybenefitsofpre-fabricatedconstruction

• Sustainablematerialswithchainofcustodycertification

• Open,pre-insulated,closedpanelandadvancedpaneloptions

The benefits include

• Shortleadtimes,reducedspeedandcontinuityofbuildprogramme

• Availabilityofsupplyfromanestablishedoff-sitemanufacturingsector

• Upto30%reductioninbuildprogrammeandprelimcosts

• Windandwatertightwithin5daysandnotweatherortemperaturedependent

• Allowsearlydeploymentandreducedrelianceonfollow-ontrades

• Savingsinsitelabourallowingmultipletradesworkingsimultaneously

• Reducedsitedeliveries,trafficmanagementandsuppliercall-offs

• Off-sitemanufacturingconsistencyandqualitycontrol

• Lessrelianceonsitesupervisiontocheckquality

Where timber frame is used

• Anybuildingupto18minheight,fromtypically1to7storey

• Wheresustainablelowcarbonbuildingsolutionsarerequired

• Todeliverasecureandweatherproofenvelopquicker

• Forlightweightsolutionsonpoorgroundortransferslabs

• Toprovide“whole-house”solutions

• Asinfillpanelsforconcrete,steel,glulamframe

What else to consider

• EarlydesignteamintegrationanduseofBIMasrequired

• Preparationandcompletenessofdesignstoallowearlyoff-sitemanufacture

• Understandingtimberframeopportunitiesfortheremainingsupplychain

• Afullunderstandingoftheprogrammingopportunitiesforfollow-ontrades

• SiteSafefireriskmitigationconsideredatcoststage,designstageandon-site

• Theneedforaccurateandlevelfoundation/slabsettingout

• Othermaterialstoprovideexternalenvelopeandinternalfinishes

Design flexibility and value engineering

The design of lightweight structural timber is inherently flexible, with the system suited to brownfield and greenfield locations. Additionally, the off-site pre-fabrication of system components offers ample opportunity to provide value engineering of designs whilst maintaining the specific requirements of the project. Typical examples of value engineering opportunities include; standardisation, optimised wall and floor designs offering reduced under-building to minimise foundations and less work for follow-on trades.

Off-site manufacturing capability

The UK timber sector is made up of several hundred small, medium and large UK firms, involved in the design, manufacture and construction of buildings which use structural timber. The industry utilises the latest in automated manufacturing techniques, CAD/CAM technology and quality assured processes.

Site erect and project management

The sector has a heritage in on-site construction and project management supervision. This is coupled to a UK network of trained and qualified erect teams with the support of experienced craneage and plant suppliers to ensure safe and controlled site erect service.

Engineering certification and supervision

Timber frame designers will engage with the client’s design team from an early stage in any project. They will work with clients from initial enquiry, through tender stage and then through to project commencement and throughout the programme of the works. This includes the provision of structural appraisals, line and point loads structural certification for use at building warranty stage.

Cost efficiencies

Structural timber guarantees a faster construction time, requiring around 20% fewer on-site labour days and a shorter construction period overall. This results in reduced disruption to local communities and tidier, safer sites. The cost efficiencies of structural timber continue through the life of the structure, delivering up to a 33% reduction in energy consumption for a large detached house and a 20% reduction for apartments.

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Building regulations and legislation compliance

Structural timber provides a fabric first approach to legislation compliance. It minimises the environmental impact of materials, ensures responsible sourcing and delivers airtightness and acoustic insulation. Specifications offer solutions for thermal regulations in England and Scotland. Currently, 85% of all passive houses are built in timber, and timber buildings were the first to reach CSH levels 5 and 6. The material is also well positioned to meet increasingly strict environmental standards, as set out by national, regional and local governments.

Environmental credentials

Timber is the most sustainable form of construction, as wood is effectively carbon neutral, with structural timber benefiting from the lowest embodied CO2 of any building material. It is also a natural carbon sink and offers a unique low embodied carbon material resource. Structural timber also benefits from being the only organic, non-toxic and naturally renewable building material, whilst minimising energy consumption during the manufacture process.


Other types of structural timber constructionThe diversification in the structural timber specification has broadened the appeal of using timber in construction, resulting in attractive and desirablebuildings,whichcanbebuilthigherandtoincreasinglystringentenvironmentalstandards.Nowondermoreandmorebuildersarebeginning to appreciate the benefits of the range of structural timber solutions on offer.

Glulam (engineered wood)

Glued laminated timber is a way to create large structural

timber members that cannot normally and efficiently be

sourced direct from the tree. Glulam can effectively be

used in nearly any location where a steel or concrete

product can be used. Typical standard section sizes range

from 45mm to 240mm wide in depths of up to 1200mm.

However, larger bespoke sizes are available for projects.

Glulam is typically whitewood based but other bespoke

forms are available.

3 Sustainable material

3 Appearance and aesthetic finish

3 Structurally stable in fire with large sections

3 Good strength to weight ratio

3 Many sizes and shapes available

NOTE: Similar products are Laminated Veneer Lumber (LVL), Duo Lam, Tri Lam and Laminated Strand Lumber (LSL) except these do not come pre-curved; however curves can be cut out of these products.

Where used

• Postandbeamstructuresorpartofotherelementmethods

• Straightorcurvedcolumnsandbeamsasfeaturemembers

• Hiddenstructuralfloorbeamsandsometimesjoists,roof purlins and sometimes rafters

• Portalframesforspecialistactivities-saltbarns,equestrian, leisure and sports facilities, public spaces for attractive roof aesthetics

What to consider

• Generallyafinishedproductsogoodprotectionduringthe construction period required

27

Cross laminated timber (CLT)

CLT is from the family of solid wood composites made

up of timber boards bonded together, at right angles to

one another, under pressure to provide 80mm to 300mm

deep sections. The boards can come in multiple sizes

with panels 4.8m by 15m long possible.

3 Sustainable material

3 Reduced site construction / programme time for panel construction

3 Door and window opening pre-formed

3 Low shrinkage

3 Reduced site works and waste

3 Ease of airtightness detailing

3 Can avoid thermal bridging

3 For high rise developments weight reduction for reduced thickness of transfer slabs

3 Foundations beam reduction from relatively low self-weight

Where used

• Anybuildingfromtypically1to12storey

• Externalandinternalwallconstruction

• Roofconstruction

• Floorconstruction

• Whereexposedtimberfinishisrequirede.g.ceiling finishes, wall finishes

• HealthandSafetybenefitsofpre-fabricatedconstruction

What to consider

• Designfreezeatanearlypointtoallowforoff-site manufacture

• Accuratefoundation/slabsettingout

• Requiresothermaterialstoprovideweatherproofenvelope

• Follow-ontradesforinsulationandfenestration

• Donotusebelowground

• SiteSafefireriskmitigation


Structural insulated panels (SIP)

A SIP is a structural panel comprising structural boards,

typically orientated strand board (OSB) that encase a rigid

insulation board - sometimes called a sandwich panel.

The SIP panel thickness typically ranges from 140mm to

250mm. The rigid insulation is either pumped in and set

to auto-bond the skins to the insulation, or is adhesively

bonded expanded polystyrene; different supply chains

offer different insulation and thickness types.

3 Low carbon design option with both embodied and in-fabric energy performance

3 Works can continue through cold weather

3 Wet trades reduced or omitted

3 Single point responsibility for structure

3 Whole frame solutions available for walls, floors and roofs from one company

3 Health and Safety benefits of pre-fabricated construction

3 Sustainable material chain of information available

3 Reduced site construction / programme time for panel construction

3 Door and window opening pre-formed

Where used

• Anybuildingfromtypically1to4storey

• Sustainablelowcarbonbuildingsolutions

• Whereaquickerwaterproofenveloprequired

• Lightweightsolutionsonpoorgroundortransferslabs

• Overexistingstructures

• Speedon-sitetoreduceneighbourhoodconstruction nuisance impact

• Whole‘house’solutions

• Infillpanelsforconcrete,steel,glulamframe

What to consider

• Designfreezeatanearlypointtoallowforoff-site manufacture

• Understandingoftimberframeinthesupplychain

• Sequenceandprogrammingfollow-ontrades

• SiteSafefireriskmitigationconsidered

• Accuratefoundation/slabsettingout

• Requiresfollow-ontradestoprovideweatherproofenvelope

29

Oak frame

The generic term oak frames refers to post and beam

structures using cut-from-the-tree timber sections;

typically oak but other woods available such as

Douglas Fir, Larch, Chestnut and imported hardwoods. A

significant amount of oak timbers used in the UK come

from France and northern European states. The use of

historic and traditional carpentry jointing such as Mortice

and Tenon techniques is commonplace although for the

larger structures metal connections are used.

What to consider

• Expertiseincarpentryandexperienceofwoodselection

• Selectionofcorrosionresistantfasteningsandmetalplates

• Largesectionsizeswherefissuresandshakesinthetimber may occur over time

• Co-ordinationwiththeinfillpanelsandglazing

• Co-ordinationoffollow-ontrades

• Weatherprotectionandsiteprotectiononaestheticelements

Where used

• Typicallyupto3storeyframes

• Featureexposedaestheticandfeaturetrusses/roofs

• High-enddomesticself-buildmarket

• High-endexternalgaragesandpartofotherformsofbuild


Contributors to the guideWe are pleased to identify those manufacturers and suppliers who provided rates and pricing of the components included in this guide. Should the reader require more specific costing or tendering information these organisations will be more than happy to support you with your project.

Stewart Milne Timber Systems Peregrine House, Mosscroft Avenue, Westhill Business Park, Aberdeen AB32 6JQTel: 01224 747000

Falcon House, Curbridge Business Park,Downs Road, Witney, Oxon OX29 7WJTel: 01865 303900 www.timbersystems.stewartmilne.com

Deeside Timber FrameSpurryhillock Industrial Estate, Broomhill Road, StonehavenAB392NHTel: 01569 767123 www.deesidetimberframe.com

Shire Timber and Truss LtdKnowsthorpe Gate, Cross Green Industrial Estate, Leeds,WestYorkshireLS90NPTel: 0113 249 2120 www.shiretimberengineering.co.uk

Lowfield Timber Frames LtdLowfield, Marton, Welshpool, Powys SY21 8JXTel: 01743 892001 www.lowfieldtimberframes.co.uk

Frame-Tech Structures LtdLock Way, Ravensthorpe, Dewsbury WF13 3SXTel: 01924 481548 www.frame-tech.co.uk

Oakworth Homes LtdUnit 8 Orgreave Close, Handsworth, SheffieldS139NPTel: 0114 288 9554 www.oakworthhomes.co.uk

Thanks to Alex Goodfellow Managing Director

Thanks toMartin Thomson

Estimator

Thanks toMike Onions

Technical Director

Thanks toDarren Jarman Managing Director

Thanks toPaul Williamson

Commercial Manager

Thanks toJohn Capper

Managing Director

31

Design flexibilityWhatever the building project - medium and low-rise residential buildings, commercial projects, leisure facilities, schools or hotels - structural timber offers unrivalled versatility and design flexibility.


Head officeStructural Timber Association The e-Centre Cooperage Way Alloa FK10 3LP

t: 01259 272140 f: 01259 272141 e: [email protected] w: www.structuraltimber.co.uk

ARTWORKANDDESIGNBYANIDEALW

ORLDWW

W.ANIDEALW

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