Passivhaus : has it’s time come?

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Each year the RIBA (Royal Institute of British Architects) awards the Stirling Prize to the ‘best’ architecture project in the UK (or & EU pre-2015). The award is arguably the most prestigious in the UK. Previous winners include: Foster + Partners ‘Gherkin’, Gateshead Millennium Bridge and The Scottish Parliament; all of which have become iconic examples of British architecture.

This year’s prize is awarded to Mikhail Riches’ Goldsmith Street, a social housing project in Norwich built to ‘Passivhaus’ standard. This project, consisting of 105 super-efficient homes, is not only the first social-housing scheme to take this coveted prize; it is also the first Passivhaus project to win.

 

Including a passive, social-housing scheme in this list reflects the importance of low-carbon and sustainable design that we hope will become increasingly synonymous with good architecture in­­ our future.

Passivhaus is on the rise in the UK: currently there are around 270 certified Passivhaus projects in the UK, and 145 under development. The first certified Passivhaus in the UK was Y Foel, a home built in Wales in 2009. The first in Scotland, Tigh-Na-Cladach  (‘House by the Shore’), was also the first Passivhaus certified social-housing project in the UK. Built in 2010 in Dunoon, it was designed by Gokay Deveci, an architect and professor at Robert Gordon University who has been at the forefront of a number of low-energy and sustainable projects across the UK.

 

What is Passivhaus?

It is a voluntary building standard developed in Germany in the 1990s, that ensures an extremely low-energy use building. The standard follows a ‘fabric-first’ methodology, resulting in very low heat loss:

  • very high levels of insulation including high performance windows and insulated frames
  • airtight building fabric
  • ‘thermal bridge free’ construction
  • maximising passive gains – orientation, shading
  • typically a mechanical ventilation system with highly efficient heat recovery (MVHR)
Passive Principles

Diagram: Passive Principles

 

The building is heated by orientating for maximum solar gain, while shading can prevent overheating in summer. MVHR allows the building to breathe, bringing in fresh air, which is heated (or cooled) by, but not mixed with, the interior air. This results in a very low energy heating system and good indoor air quality.

Passivhaus standards allow 120kWh/m2/year for energy use with only 15kWh/m2/year of this is allocated to heating. To put this into context, a typical building’s energy use is 360kWh/m2/year!

Local councils and others are beginning to understand the benefits of Passivhaus and other green building methods when applied to social housing. As the buildings are so energy efficient, heating demands are reduced by 75%, therefore, running costs reduce significantly. For Councils, implementing these standards into social housing schemes is a brilliant way to reduce fuel poverty amongst tenants, and is a more carbon friendly option – helping to bring the UK closer to its target of net-zero emissions.

 

Is Passivhaus for you?

Whilst Passivhaus is a great design methodology, if you are not aiming for Passivhaus certification, we advocate a ‘fabric-first’ approach to get the most out of your building.  Not only for new build – we recommend implementing if you are extending or altering your property; as it will improve efficiency, increase comfort and help minimise energy bills.

 

 

With current worldwide concern for the escalating climate crisis, coupled with widespread housing shortages, the time to address and improve our methods of building have never been more important. Both for us as individuals and our governments. Hopefully Goldsmith Street is an indication that we can, and will, move in the right direction.