AJ sustainability editor Hattie Hartman presents three recently completed Passivhaus projects
More from: Three Passivhaus projects
The first UK Passivhaus building was built in Wales in 2009. The number of completed buildings in the UK today is more than 250, when you include multi-family housing units. Several new build housing projects of 40+ units are now complete, with many more in the pipeline.
Those who swear by Passivhaus laud its quality assurance. ‘It’s a culture shock to go back to traditional construction after you’ve worked on a Passivhaus building,’ says Marco da Cruz of Sjölander da Cruz Architects. There is no doubt that a Passivhaus project requires more on-site supervision, particularly at the critical stage when airtight membranes are installed.
Jon Bootland of the Passivhaus Trust notes common ‘flashpoints’: insulation of slab and foundations, installation of insulation and installation and commissioning of MVHR units. ThePassivhaus Trust is developing guidance for these key stages, to be published in early 2015.
Most successful projects rely on an enthusiastic Passivhaus champion but, as the scale of projects increases, the approach needs to be systematised to maintain quality control. Another effect of the increase in projects is innovation among product manufacturers and reduced costs. In early projects, such as Lancaster Cohousing, conventional cavity wall construction was the most cost-competitive method. Recent projects are exploring different ways to meet the Passivhaus standard with timber.
But there are still plenty of Passivhaus sceptics. Some see the standard as too narrow a tool, focused solely on operational energy. It’s easy to build a low-energy house with energy-hungry materials and still achieve certification. The onus is entirely on the designer to use low-impact materials. Simon Sturgis of Sturgis Carbon Profiling asks what will happen in 60 years, when airtightness membranes fail. Will Passivhaus buildings have to be completely disassembled to install new membranes?
Interestingly, major housing practices like PRP Architects and HTA are looking at Passivhaus but have nothing in the pipeline yet. HTA’s Rory Bergin says: ‘My preference is for dynamic simulation models rather than spreadsheet software like the Passivhaus Planning Package. You can use a dynamic model to improve your design much more easily. And, when we get seamless transfer from BIM to dynamic simulation tools, I can’t see a future for any other approach.’
Nonetheless, Passivhaus has already impacted the wider industry in profound ways. Both among designers and manufactures, Passivhaus has increased awareness and understanding of issues such as solar gain, cold bridging, airtightness and ventilation systems. As the health and wellbeing agenda takes hold, Passivhaus is likely to yield important lessons about indoor air quality.
AHMM associate director Nic Crawley points out that the Passivhaus standard is effectively open-source, with huge resources readily available to those with interest and motivation to learn. Passivhaus training sessions at AHMM have attracted far more interest than other CPDs. In short, whether you advocate Passivhaus or not, it’s an excellent tool for promoting green design.
- Hindolveston Road Housing by Mole Architects
- River Studio by Sjolander da Cruz Architects
- Lancaster Cohousing by Eco Arc
Passivhaus projects in the pipeline
- Parliament Hill School, London, A Studio
- Burry Port School, Wales, Architype
- Stebon Primary School, London, Architype
- Enterprise Centre, University of East Anglia, Architype
- King’s Hawford School, Worcester, Multi-Use Sports and Performance Hall, Associated Architects
- University of Leicester Centre for Medicine, Associated Architects
- Savoy Pier, London, Bere Architects
- St Benedict’s School extension, Ealing, London van Heyningen & Haward Architects
Residential new build (30+ units)
- Bridgecroft, Herefordshire, Architype 150 units
- Agar Grove, Hawkins\Brown and Mae Architects, 360 units
- Carrow Quay, Norwich, Ingleton Wood Architects, 250 units
- Quad, Clay Farm, Cambridge, two-unit prototype for 209-unit scheme, PTE,
- Cohousing Woodside, Muswell Hill, London, PTE, 30 units
- Goldsmith Street, Norwich, Riches Hawley Mikhail Architects, 109 units
- Erneley Close, Manchester, 2e Architects and Eric Park Architect, 32 units
- Wimcote House, Portsmouth, ECD Architects, 107 units
- Parkview Hub, Thamesmead, SustainablebyDesign, 18 units
Plus numerous single-family homes