Delivering a genuinely sustainable built environment -the challenges and opportunities

Prof. David Strong Oxford Brookes University

20th May 2013

Bizarre!

Even more bizarre! - Not smart, just plain dumb!

• Energy used within buildings accounts for nearly 50% of UK CO2 emissions with

a further 10% arising from the production of construction materials

• Each year the UK construction industry uses 6 tonnes of building materials per

head of population

• Waste from materials production and construction amount to 151 million

tonnes per annum or 35% of UK total waste.

– 90+ million tonnes p.a. construction & demolition waste

• 20% of which is new material!

Key impacts of the built environment

Canary Wharf

QAPhotos/NMEC

Regulatory and other key drivers

in the UK

Policy Drivers

Multiplicity of policy drivers - some 70 different policy and

legislative instruments

DECC

CLG

BIS

HMT

Defra

Key regulatory and other drivers

• Revisions of Building Regulations Part L

• Code for Sustainable Homes

• E.U. Energy Performance of Buildings Directive

- Building energy certification and labelling (DEC’s &

EPC’s)

• New fiscal instruments and tax incentives

EU Energy Performance of Buildings Directive (EPBD)

– Energy performance certificates

• EPC’s

• DEC’s

UK Zero Carbon legal requirements

• All new homes are required to be “zero

carbon” by 2016

• The zero carbon requirement relates to “regulated

energy” (e.g. heating, lighting, ventilation & hot

water) NOT appliances (e.g. cooking, TV etc.)

• Homes can be made zero carbon by on-site renewable

generation and/or “allowable solutions”

• Rules regarding “allowable solutions” not yet published

• All new non-domestic buildings zero carbon

by 2019

EU Energy Performance of Buildings

Directive (Recast 2012)

• requires all new buildings in 27 Member States to

be “nearly zero energy” by 2020

• Requirements & definitions still being discussed

by Member States

• German PassivHaus Standard being promoted by

many observers

Concerns Regarding zero carbon/zero

energy requirements

• Definitions are still ambiguous

• Cost implications

• Practical engineering constraints

• Concerns regarding perverse outcomes and

unintended consequences

Environmental Rating systems for buildings

• UK • BREEAM (Building Research Establishment Environmental

Assessment Method)

• BREEAM “Excellent” now mandatory for all new public

buildings

• UK government “Code for Sustainable Homes” derived

BREEAM Ecohomes standard

• USA • LEED (Leadership in Energy and Environmental Design)

• Most systems are based on assessing & rating a wide range of

environmental impacts associated with the building (e.g. energy,

ecology, internal environment, transport links etc.)

• In many countries rating systems are becoming used

as de-facto standards

What does a genuinely low carbon building look like?

Hopefully, not like this!

Or like this?

Or this?

Or this? Beaufort Court

RES HQ, Beaufort Court, Kings Langley, Herts.

Where do we begin?

• What are our points of reference?

• What can we learn from

– history?

– nature?

– 1st generation attempts to design/construct

sustainable buildings? • What has gone wrong?

• What will it take to deliver the next generation of

sustainable buildings?

Lessons from the past - vernacular

architecture

Vernacular architecture has a form and function which enables

- comfortable conditions to be achieved (often in very hostile climatic

conditions)

- optimum and sustainable use of indigenous materials

- low environmental impact

Lessons from nature - biomimicry

• Buildings should fully exploit the natural systems available

for free to provide: - ventilation - cooling - heating - daylighting

• Climate excluding vs. climate adaptive buildings - Bio-climatic design is much more challenging

- Greater care required in construction, operation and maintenance to

achieve optimum performance

Bioclimatic Design

Utilising a site’s free climatic resource (sun, light,

wind, air and water) to maximise comfort and

minimise energy use.

A modern term for an ancient approach.

Necessity encouraged early designers to seek

optimal comfort from natural resources. Climate

change demands we learn to do the same.

Enhanced wisdom

- Meticulous site analysis

- Advanced modelling

(Computation Fluid Dynamics, thermal

modelling, daylight analysis etc.)

Resulting in simple buildings and places which are

fundamentally more responsive to location, climate

and human needs.

Major concern that the sustainability

and/or zero-carbon agenda could lead to:

• Imbalance

• Missed opportunities

• Highly perverse outcomes

The Performance Gap

Why don’t most low carbon sustainable buildings

perform as well as the initial designs claim?

Design intent vs. actual

performance Is it even compliant with Building Regulations?

City Hall

“Norman Foster’s City Hall, which is billed as an exemplary

sustainable building, uses 50% more energy than it was designed to do.”

Why? What’s gone wrong? Where is the discrepancy?

A great example of dis-integrative design

The ‘Gherkin’

“ London’s first ecological tall

building..”

Predicted energy consumption 150kWh/m2

• But what happened when the fire regulations were

applied?

• No independent environmental assessment

• How much energy does it use in practice?

• Are the sceptics right – and if so to what extent?

Portcullis House

“It is highly energy efficient. It uses only about one third as much fuel as

a conventionally air conditioned building. Heat is recycled from exhaust

air, and cooling is provided by groundwater from boreholes.”

But what’s the reality in practice?

90 450 kWh/m2/yr

‘A’ Rated in theory

‘G’ Rated in practice

What’s the truth about Europe’s most expensive office building?

A great example of unmanageable complexity!

Success stories

• Not a total litany of despair!

• However, good examples are hard to find

– Brighton & Hove Library

– National Trust Heelis Building, Swindon

– Elizabeth Fry building, University of East

Anglia

Brighton and Hove Library

• Is this the UK’s most energy efficient non-domestic building?

• Stirling Award shortlist & Prime Minister’s Award for Better Public Buildings

Ethical Award 2006

• Believed to be the first PFI procured building with explicit energy

performance target:

• Total energy consumption not to exceed 40kWh/m2 p.a.

• Vital we learn the lessons from these buildings and share best practice

Heelis Building (National Tryst HQ, Swindon

• 2007 Sustainable Building of the year

• Design target 50.2 kgCo2/m2 p.a.

• Actual performance 62.5 kgCO2/m2 p.a.

• Used as a Soft Landings development Case

Study

Elizabeth Fry Building UEA • Opened in 1998

• Arguably still the UK’s most energy

efficient non-domestic building

• Annual energy use in 1997 (very similar in

2010) Total: 96kWh/m2 p.a.

– Electricity: 61kWh/m2 p.a.

– Gas: 35 kWh/m2 p.a

• Law of Diminishing Returns

• Law of Unintended Consequences

• Murphy’s Law

In addition to the construction issues, what

are the key risks from the zero-carbon

agenda?

• Summertime overheating

• Flood resilience

• Transport

• Security

• Acoustic performance

• Indoor air quality/Health problems

• No IAQ regulations

• c1900 about 50 materials (mostly natural)

• Now over 50,000 compounds and chemicals

Beware the law of unintended

consequences

Murphy’s Law (or the Law of green bling)

Over-reliance on complex / unproven technologies

• As a rule, simple building technologies work,

complex ones generally fail!

• Misselling/misspecification of technologies

can have hugely damaging consequences

• Three recent examples:

• Micro chp

• Micro wind

• Air source heat pumps

Micro-chp

• Massively over-hyped • over 60 references to micro chp in 2003 Energy White

Paper

• “6000 to be installed in fuel poor homes by 2004” • Margaret Becket Labour Party conference 2003

• Carbon Trust trials identified serious technical and

economic shortcomings • Not suitable for low heat demand homes

• Not suitable for intermittent use

Micro-wind

• 3 independent trials of over 50 micro turbines

found that they were not cost effective in the

urban environment • Manufactures/installers claims were exaggerated

• In many cases they were net consumers of energy!

• Only suitable in exceptional

circumstances/ very exposed sites

Air-source Heat Pumps

• Can the manufacturers seasonal performance claims be

achieved in practice?

• Impact of evaporator de-icing on seasonal performance? • Performance in heavy snow conditions

• What about noise impacts in the

urban environment?

• EST trials to provide “objective” data • Report published Sept 2010

• Shows that a “well performing heat

pump can produce a COP of 3.0 ….

….should give consumers confidence”

EST “objective” trial of 28 ASHP’s

• 6 of the 7 top performing heat pumps had “estimated

efficiencies”

• Of the remainder average COP =1.9

• Only one achieved a COP of 3.0

What is 2nd generation sustainability?

• Achieving ultra-low carbon without the eco-

bling

• “Designing out” complexity and cost

• Recognising that there are no technological

“magic bullets” • Large scale renewables are (generally) always

better than micro-scale

• Realisation that profoundly different ways of

thinking are required

What is the best way of delivering an

ultra-low energy requirement building

(whilst also avoiding perverse outcomes,

diminishing returns and Murphy’s Law)?

• And avoiding the greenwash!

Focus on the really important aspects of design

• Examples:

– Building envelope/fabric

– Air permeability/indoor air quality

– Daylight

Passivhaus – an intelligent “whole-building” energy performance standard

3 fundamental requirements

• Ultra –high fabric/glazing thermal performance

•Space heating <15 kWh/m2/year

•Primary energy (heating, lighting, domestic

hot water, appliances) <120 kWh/m2/year

• Very low air permeability (<1 m3/(h.m2) @ 50Pa)

• Mechanical ventilation with heat recovery

• Build tight ventilate right

• No requirement for a conventional space

heating system

• Clinically proven health benefits •Significant reduction in childhood asthma

•Ultra low owning and operating cost

•Reliable/robust approach

•Based upon sound building physics

and over 25 years of research

•Comfortable and healthy

•Passivhaus Planning Package (PHPP)

•Robust summertime overheating

assessment (c.f. SAP/SBEM)

• The standard can be applied to

buildings other than housing

The Passivhaus Standard

-key benefits

Downsize or remove the wet

heating system Meet carbon targets without excessive

renewables and “eco-bling”

Things that you ‘save’:

reduce the build cost

Thermal bridge free design

Airtight construction

The devil (or God) is in the detail

It’s proven to work

Recorded and

demonstrable

performance in

10,000+

buildings in

Austria and

Germany.

Case Study 1

Highfield ultra-low energy home

Highfield • Fabric first design

– DER = 4.6 kgCO2/m2 vs. TER 14.5 kgCO2/m

2

– Air permeability =1.5 m3/h.m2 @50Pa

• No conventional heating system

– Woodburner & solar thermal connected to thermal store

• Ultra-low pressure loss MVHR linked to earth duct

• Exemplary IAQ & avoidance of summer overheating

• Very low fan power (550kWh p.a vs. Appendix Q =1424 kWh p.a)

Low cost earth duct

• Cost about £800 (fully installed) • c.f. Rehau system @ approx. £5k

• Initial performance results: • Winter: Air inlet -8C, Air outlet from Earth Duct +4C

• Summer: Air Inlet 30C, Air outlet from Earth Duct 19C

Highfield Heating/Ventilation strategy

TSB Building

Performance Evaluation

project

2012 -2014

Case Study 2

Dog Rehoming Centre

• Dog’s Trust 17 rehoming centres across UK • New Centres constructed at Harefield, Dublin, Canterbury

• Energy usage at modern centres over 400kWh/m2 p.a.

• Typical CAPEX £2500/m2 (M&E component 20%)

Harefield Dog Rehoming Centre Key Issues

• Complexity of building service equipment

- air conditioning/high lux levels etc.

- very complex systems have been specified

• Thermally inefficient built-form/poor air-tightness

Shrewsbury Rehoming Centre

• Radical rethink of the building services

– Avoiding all unnecessary cost & complexity

– Adoption of Passivhaus standards for fabric and air-

tightness & more thermally efficient layout

• Adopting a “whole system” approach to the building

design and energy systems

• BSRIA Soft Landings Framework to ensure energy in-

use is better than design

Rehoming Centre -Key Achievements

• BREEAM Outstanding (highest rating ever achieved)

• 60% in-use energy reduction (400kWh/m2 reduced

to less than 150kWh/m2 p.a) • zero-carbon

• Improved comfort/health/productivity for occupants

• Exemplary sustainable building at lower CAPEX and

OPEX

Key findings from a review of the research evidence associated with daylight in buildings

• Over 80 research papers & books reviewed

• Objective evidence supported by empirical data included in study

• Evidence synthesised & collated into building type/function:

– Healthcare

– Education

– Workplace (offices and industrial)

– Retail

– Residential

Key research findings -Healthcare

• a reduction in the average length of hospital stay

• quicker post-operative recovery

• reduced requirements for pain relief

• quicker recovery from depressive illness

– Impacts on obesity & heart disease

• Sunlight also has disinfectant qualities

Education • access to daylight has been shown to result in

a dramatic (and demonstrable) improvement in student academic achievement:

– behaviour,

– calmness

– focus.

Copyright: United World College of South East Asia(UWCSEA) – East Campus Singapore

Other building types/functions • Workplace

– numerous studies have identified a preference to work near windows... An ample and pleasant view was consistently found to be associated with better office worker performance.

• Retail establishments – research shows that a substantial improvement in sales can be

achieved in daylit shops. Using daylighting also has aesthetic benefits that encourage customers to enter the store, create a more pleasant shopping environment and improve colour rendering.

• Residential – many of the studied benefits associated with daylight and connections

to the outside world can be equally realised, thus contributing to sensations of wellbeing.

The Distinctive benefits of Glazing

The social & economic contribution of glazed areas to sustainability in the built environment

Available for download from:

www.davidstrong.co.uk

What’s are the two greatest risks associated

with delivering the CO2 reduction agenda?

• Technical?

• Skills?

• Behavioural?

• Political will/leadership/courage?

Risk 1Commercial vested interests • The huge vested commercial interests in selling M&E

plant and equipment • which through intelligent design, can often be “designed-out”

• There is no commercial value in selling nothing (nega-

plant)

• Problem exacerbated by architects

and consultants who link their fees

to the value of the capital work! • Introduces a perverse incentive to

over-specify

Risk 2 The Khazzoom-Brookes

Postulate

“Energy efficiency improvements that, on the

broadest considerations are economically justified

at the micro level, lead on to higher levels of

energy consumption at the macro level”

Otherwise known as the “rebound effect”

Risk 2 The rebound effect

• First proposed by William Jevons in

his 1865 book “The Coal Question”

- known as the Jevons Paradox

• Jevons observed that England’s coal

consumption soared after James

Watt’s improvements to Newcomen’s

earlier design

William Stanley Jevons

Will the Government’s CO2 reduction targets be achieved?

• The answer is almost certainly “no” unless there is

a profound change in consumer behaviour.

• Vital that the grid is decarbonised by deploying large

scale renewables where they will be most cost

effective

Key Question

Addressing the challenge of climate change requires a

holistic approach to deliver genuine sustainability.

• Whole system thinking is essential:-

• Vital to optimise the entire system, not just parts

• Collaborative, multi-disciplinary, integrated team working

• Working to find natural solutions to reduce our dependence

on energy-intensive systems

Managing Risk and Adding Value

Intelligent Systemic thinking

• Looking for synergistic solutions which address and resolve multiple problems

and issues simultaneously

• Working within the constraints of natural systems, whilst fully exploiting the

opportunities offered by nature to ventilate, heat, cool and illuminate our

buildings.

• Delivers huge social, human, environmental and economic benefits

• Optimising the whole system by designing out waste and improving

efficiency

• Adopting an eco-minamalist approach

• Doing more with less by tunnelling through cost barriers

Tunnelling through the cost barrier

…to even BIGGER and cheaper energy savings

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cost-effectiveness limit

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tunnelling through the cost barrier…

cumulative resource savings

Source : Natural Capitalism Paul Hawken, Amory B Lovins, L Hunter Lovins

Summary • Sustainability is a complex web of interrelated issues

• a whole systems approach is essential

- Cannot be addressed through a “broad-brush” or

single issue approach

- Collaborative, integrated multi-disciplinary team

working is essential

• “design-out” technical complexity and cost by rethinking,

challenging and improving

Summary (cont.)

• Genuinely sustainable buildings are about much

more than zero-carbon

• Healthy, comfortable, productive, ultra-low CO2 buildings fit

for people and the planet.

• Strive for elegant simplicity

“making the simple complicated is commonplace;

making the complicated simple, awesomely simple,

that’s creativity” Charles Mingus

David Strong Consulting Ltd

www.davidstrong.co.uk