The document discusses domestic energy efficiency standards in the UK housing sector. It notes that standards have changed recently with the withdrawal of the Code for Sustainable Homes and restrictions on local planning authorities requiring higher energy standards. This has led to confusion among local planning policies. Higher standards like Passivhaus are still achievable with care in design, construction and quality control. Proper insulation, airtightness, ventilation and installer training are keys to success. A local example of a Passivhaus built to high standards on time and on budget is provided.

1. Domestic Energy Efficiency: Where now?
Colin Powell BA(Hons) DipArch Msc RIBA
gcp : architecture : energy : sustainable design

2. gcp
architecture : energy : sustainable design
gcp are one of the leading housing
design practices in the region with a
specialist knowledge in the design of
low energy buildings
Our pragmatic approach and
experience supports our clients in
developing realistic and deliverable
solutions
Our collaborative experience,
working in partnership with
contractors, gives us an
understanding of the challenges for
delivery of high performance
buildings in a competitive
construction market
int roduc t ion
Sidford Road, Bedminster : 71 Homes for Knightstone Housing
2016 Zero Carbon Standard & AECB Silver Standard
gcp Chartered Architects

3. gcp
architecture : energy : sustainable design
The Government ‘Housing Standards
Review’ – concluded in 2015 -
changed the landscape for standards
relating to housing design
Most significantly the Code for
Sustainable Homes was withdrawn
with some elements of the Code
incorporated into revised Building
Regulations
In addition the National Planning
Policy Framework was modified to
restrict powers of Local Planning
Authorities to require higher (than
building regulations) energy efficiency
standards
Following the May 2015 general
election - Government announced it
did not intend to proceed with the
2016 Zero Carbon Standard or
Allowable Solutions mechanisms
Energy Performance of Buildings
Directive (EPBD) (currently) includes
requirements for ‘cost optimal’
reviews of minimum energy
performance standards – the next
review should take place in 2017
EPBD also requires that all new
buildings (in member states) should
be ‘Nearly Zero Energy’ by 2020
background

4. gcp
architecture : energy : sustainable design
Planning Authorities in the local area
are illustrative of the confusion the
recent changes to regulatory
standards have generated
Many authorities were slowly moving
towards adoption of energy or carbon
reduction standards commonly
expressed through target
requirements based on the Code for
Sustainable Homes or ‘Merton Rule’
standards for inclusion of renewables
The changes to National Planning
Policy have left many of these
processes in limbo, or being rejected
at the inspection stage
Bristol City Council Policy BCS14
requires 20% reduction in carbon
emissions through use of renewables
North Somerset Policy CS2 requires
10% reduction in energy through use
of renewables
B&NES are currently seeking
approval for a policy requiring 10%
energy through on-site renewables
Merton-style policy
Other authorities in the region have
‘soft’ policies requiring statements on
sustainability or energy efficiency
local landscape

5. gcp
architecture : energy : sustainable design
The 2017 Housing White Paper
focuses on delivery of numbers
and the economic challenges for
home ownership – particularly for
first time buyers
but:
“The equivalent of the
population of Glastonbury will
die this winter from being in
fuel poverty”
(calculated from Govt statistics for ‘excess winter
deaths’ and WHO calculation)
Over 10% of UK households
cannot afford to keep their house
warm
Energy providers are predicting
steep rises in energy prices in
spring this year
a re w e t a k ing our e ye s of f t he ba ll?
DECC – monthly retail price indices
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Fuel price indices in the domestic sector
in real terms 1992 to 2012
Coal and smokeless
fuels
Electricity
Gas

6. gcp
architecture : energy : sustainable design
B.Regs Pt.L ZCH AECB Silv. PassivHaus
FEE: Target
kWh/m2.a
42.3 41* 40 15
Floors 0.15 0.11 0.11 0.10
Walls 0.18 0.14 0.14 0.11
Roof 0.18 0.11 0.09 0.10
Windows 1.4 1.4 0.85 0.85
Bridging 0.085 0.04 0.01 0.01
Permeability 4 m3/m2/hr 2 m3/m2/hr 1.5 ac/hr ** 0.6 ac/hr
Ventilation Extract only MVHR MVHR MVHR
* Zero Carbon Home FEE targets vary with house type (end-terr/mid-terr/flats etc)
** AECB Silver permeability is 3.0 ac/hr for homes with MEV only – but harder to achieve other targets in the standard
St a nda rds c ompa re d
( i n d i c a t i v e v a l u e s f o r r e c e n t p r o j e c t s )

7. gcp
architecture : energy : sustainable design
• Insulation is cheap – it doesn’t
breakdown or need periodic
servicing
• Minimising thermal bridging needs
careful detailing and clear
explanation
• Installation can be poor and
needs careful quality control
• Site teams need to understand
the importance of installing
insulation without gaps or air
pathways
Going f or higher st andards – can w e do it ?

8. gcp
architecture : energy : sustainable design
• Airtightness needs to be
considered from the outset,
designers need to understand the
sequence of building operations
• Complexity is the enemy of
airtightness – try and find the
simple solutions your site team
will be much calmer!
• Test early and test often – don’t
kid yourself that you can fix it
later!
• Don’t run with scissors (or drills, or
knock holes through things with a
big hammer!)
Going f or higher st andards – can w e do it ?

9. gcp
architecture : energy : sustainable design
• Service installations should be
planned and accommodated at
design stage
• Ventilation systems should be
installed and commissioned by
suitably experienced installers
• Your plumber / electrician will
always know how to do it better /
quicker / cheaper. Try to persuade
them to do it right!
• User controls should be simple
and located where they are
needed (don’t tuck them away
behind the plant!)
Going f or higher st andards – can w e do it ?

10. gcp
architecture : energy : sustainable design
• You will spend a lot of time in the
planning stage agreeing how to
deliver higher standards
• You will spend a lot of time with
the pre-contract team agreeing
how best to deliver higher
standards
• You will need to spend time with
the site team explaining why
things are being done this way
• You will tear your hair out when
you learn that the site surveyor is
pleased that s/he saved £5 on a
cheaper tape (that doesn’t
actually stick!)
Going f or higher st andards – can w e do it ?

11. gcp
architecture : energy : sustainable design
• YES WE CAN!
• Our PassivHaus project in South
Oxfordshire – built by a small local
contractor that had never built
PassivHaus or ICF before
• Completed on-time & in-budget
• First air tightness test – 0.48 ac/hr
• PassivHaus certified even though
it faces north west
• Perhaps doing things differently
we think more about what we are
doing and don’t make
assumptions based on previous
experience
Going f or higher st andards – can w e do it ?

12. gcp : architecture : energy : sustainable design
Thank you
www.gcparch.co.uk
colin.powell@gcparch.co.uk
“The House works really well –
now we have experienced living
in a PassivHaus, we wouldn’t
want to live in anything else.”
(Client – Warborough PassivHaus)