The document discusses the Passivhaus design standard, which promotes low energy building and is applicable to various building types, focusing on energy efficiency through stringent design criteria. It highlights the benefits for clients including reduced energy costs, improved indoor comfort, and contributions to sustainability, while addressing common myths surrounding Passivhaus. The insights also emphasize the importance of engaging users and the challenges designers face in implementing these principles effectively.

1. PassivHaus - the solution for low energy building?
Colin Powell BA(Hons) DipArch Msc RIBA
gcp : architecture : energy : sustainable design

2. Content
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PassivHaus primer – a brief outline
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(why) Do clients want PassivHaus
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The problems for PassivHaus design – myths and reality
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Knowledge based design – don’t be frightened by numbers
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Challenges for the designer
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Engaging the user – achieving performance in use
gcp : architecture : energy : sustainable design

3. gcp
architecture : energy : sustainable design
Effective sustainable design requires a detailed knowledge of building science, technology and construction
Our core skills as architects provides our clients with a depth of understanding that informs our advice on energy and sustainability
Our consulting business provides the specialised knowledge of sustainable and low energy design needed to help our clients achieve their ambitions
introduction

4. gcp
architecture : energy : sustainable design
PassivHaus is a design standard for producing buildings with very low energy demand
Developed in Germany in 1991, now being used around the world as a tried and tested standard
Not only applicable to housing, it can be used for large and small buildings and refurbishment
quick outline

5. gcp
architecture : energy : sustainable design
Standard applicable to all building types
PassivHaus focusses on building energy calculated through a rigorous calculation method
Not only applicable to housing, it can be used for large and small buildings
EnerPHit standard applies PassivHaus principles to refurbishment and retrofit
offices
schools
housing
student residence
quick outline

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architecture : energy : sustainable design
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Exceptionally high thermal insulation
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High performance triple glazed windows
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Thermal-bridge-free construction
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Very low air permeability – airtight building envelope
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Comfort ventilation with highly efficient heat recovery
continuous thermal insulation
typically >300mm thick
larger windows to the south for
beneficial solar gains
continuous air barrier
To prevent air leakage
ventilation system delivers fresh air to main activity spaces
ventilation with
Heat recover to save energy
quick outline

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architecture : energy : sustainable design
Govt. Agenda for Carbon Reduction – Climate Change Act
35% Reduction in CO2 by 2020
Increasing energy costs and prospect of increasing energy instability
Planning and statutory targets for energy and carbon
legislative agenda for change
DECC – monthly retail price indices
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20
40
60
80
100
120
140
160
180
200
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Fuel price indices in the domestic sector in real terms 1992 to 2012
Coal and
smokeless fuels
Electricity
Gas

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architecture : energy : sustainable design
Clients want reliable solutions that deliver real benefits
Suspicion of complex renewable technologies that may not deliver reduced energy
Resistance to sustainability measures that are counter-intuitive
Need for solutions that are simple and robust
We are increasingly finding that sustainability is an important driver to occupiers and investors;
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Occupier concern over energy use and running cost
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New taxation (e.g CRC)
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Sustainable buildings give occupiers tangible costs savings (£5.2m saved in past 4 years)
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Holds long term property values with investors
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Now a contractual requirement for our whole supply chain
(Sarah Cary – Sustainable Development - British Land)
real-world issues
In our previous offices, energy costs were over £23,000 per annum and rising fast. Energy costs in the new office are projected to be a credit of £2,000 per annum and rising in line with energy costs, representing a £25,000 per annum saving on the old office.
(John Walkerdine - Interserve )

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architecture : energy : sustainable design
Stable internal temperatures without cold surfaces or draughts
Reduced risk of overheating
Controlled ventilation can reduce the risks of respiratory disease
Thermal performance and air- tightness through rigorous quality control at design and construction stage
Image courtesy of International PassivHaus Association
Its not just about money
“We think each person lifted out of fuel poverty will save the health service about £250 a year. Data suggests there are 20% more deaths in Oldham in winter than in summer because of extra respiratory illnesses and heart problems [linked to cold homes]. If you get a cold winter and people cannot heat their homes, you get more people suffering and turning up in A&E”
(Guardian Nov.13 – ‘Actively cutting energy bills in Oldham – Welcome to the Passivhauses’)

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architecture : energy : sustainable design
Exeter City Council
Hastoe Housing Group
Interserve
University of East Anglia
Leicester City Council
Circle Housing
Gentoo
Diocese of Worcester
University of Bradford
London Borough of Tower Hamlets
Carmarthenshire Council
East Midlands Housing Association
Raynsway Properties
Estimated over 500 completed projects by end 2013 a rate of growth consistent with Germany 20 years ago
(NHBC Foundation July 2012)
Why are clients choosing PassivHaus?
“healthy buildings”
“addresses fuel poverty”
“reduced management & maintenance”
“future proof”
“not eco- bling”
“demonstrates CSR”
“fabric first”
“massive cost saving”
“tried & tested”
“opportunity for higher revenue”
“right thing to do”

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architecture : energy : sustainable design
Myths and Reality
You can’t open the windows
PassivHaus needs no heating
Sealed buildings are unhealthy
Mechanical ventilation wastes energy
PassivHaus overheats in summer
PassivHaus are too complex
PassivHaus are too simple
Windows can be opened for comfort and cooling, buildings will recover more quickly after closing
PH do need heating – just very little – a single towel-rail or perhaps a big dog?!
Proper ventilation is designed-in and works even in cold months when you want to keep the windows closed
Efficient, well-designed Heat Recovery Ventilation saves 10 times the energy it uses
Shading and cooling are key parts of the design process and certification criteria
PH often use less technology and simpler systems
Sometimes you just can’t win! (there are plenty of examples to refute this)

12. gcp
architecture : energy : sustainable design
Myths and Reality
You can’t open the windows
PassivHaus needs no heating
Sealed buildings are unhealthy
Mechanical ventilation wastes energy
PassivHaus overheats in summer
PassivHaus are too complex
PassivHaus are too simple
Windows can be opened for comfort and cooling, buildings will recover more quickly after closing
PH do need heating – just very little – a single towel-rail or perhaps a big dog?!
Proper ventilation is designed-in and works even in cold months when you want to keep the windows closed
Efficient, well-designed Heat Recovery Ventilation saves 10 times the energy it uses
Shading and cooling are key parts of the design process and certification criteria
PH often use less technology and simpler systems
Sometimes you just can’t win! (there are plenty of examples to refute this)

13. gcp
architecture : energy : sustainable design
The energy we use is affected by different factors
•
Age of the building
Energy in buildings – using numbers to inform design
62%
19%
13%
3%
3%
Home Energy
Heating
Hot Water
Appliances
Lighting
Cooking
Energy use – average all UK homes

14. gcp
architecture : energy : sustainable design
The energy we use is affected by different factors
•
Age of the building
•
Lifestyle
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Purchasing decisions
Energy in buildings
32%
22%
29%
9%
8%
Home Energy
Heating
Hot Water
Appliances
Lighting
Cooking
Energy use – new home to current regulations
– using numbers to inform design

15. gcp
architecture : energy : sustainable design
Heat loss from the building has to be balanced with energy (heat) in to maintain comfort
We can calculate where this heat is lost by modelling
So where does all the energy go?

16. gcp
architecture : energy : sustainable design
Heat loss from the building has to be balanced with energy (heat) in to maintain comfort
We can calculate where this heat is lost by modelling
So where does all the energy go?
walls
13.2
roof
9.2
floor
4.0
windows
24.2
ventilation
48.0
Current Regs - elemental energy loss – kWh / m2
Therm.
bridges
2.7

17. gcp
architecture : energy : sustainable design
Heat loss from the building has to be balanced with energy (heat) in to maintain comfort
We can calculate where this heat is lost by modelling
So where does all the energy go?
walls
13.2
roof
9.2
floor
4.0
windows
24.2
ventilation
48.0
Current Regs - elemental energy loss – kWh / m2
Therm.
bridges
2.7

18. gcp
architecture : energy : sustainable design
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Understanding from elemental analysis enables optimises solutions
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Implications for building design from site layout to construction
Understanding the numbers helps in targeting solutions
walls
8.4
roof
5.2
floor
3.3
windows
13.7
ventilation
5.6
Therm.
bridges
0.0
PassivHaus - elemental energy loss – kWh / m2

19. gcp
architecture : energy : sustainable design
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Increased cost for construction is invested in the building fabric and insulation
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Typically 5-10% more expensive (recent studies show this reducing)
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Payback period around 20 years (but energy costs increasing)
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Protection against fluctuating fuel costs and future uncertainty
Illustration of energy cost savings for a 3-bed detached house
And provides compelling arguments for clients

20. gcp
architecture : energy : sustainable design
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Understanding the main factors that influence performance
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Site factors are significant and need to be considered
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Building form can make life easier – or more difficult
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Complex buildings may need more complex solutions – adaptive buildings that adjust with occupancy
Challenges for the designer

21. gcp
architecture : energy : sustainable design
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Construction type needs to be considered from the outset
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Traditional construction is possible – but will demand new understanding from constructor
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New materials and constructions may be worthwhile
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Clear coordination between design and construction team is vital
Challenges for the designer

22. gcp
architecture : energy : sustainable design
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Success of the project will rely on a good briefing for the end-user
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PassivHaus needs to be ‘driven’ and will take time to acclimatise - the user and the building
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Explaining the reason for controls is as important as knowing what they do
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Understanding seasonal variations will ensure comfort in different conditions
Engaging the user
On hot summer days keep the windows closed !
Heating by towel rails – press boost if you need some extra warmth
Keep the ventilation on auto and press boost if things get steamy
The boiler is small and won’t be running very much – don’t worry it’s not broken!

23. gcp
architecture : energy : sustainable design
PassivHaus are too simple

24. thank you
gcp : architecture : energy : sustainable design
www.gcparch.co.uk
colin.powell@gcparch.co.uk