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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
( - )
0
( + )
Mar
gin
al c
ost
of
effi
cien
cy im
pro
vem
ent
cost-effectiveness limit
DETOUR
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