Sceptics welcome at the Passivhaus Conference
Initially used by a few enthusiasts at the grassroots level, Passivhaus has demonstrated its effectiveness in delivering comfortable, low energy homes - and its potential in a low carbon future. We spoke to Emma Osmundsen who champions low energy and healthy design, and has been instrumental in promoting the Passivhaus standard in the UK.
Report from – Tom Harvey
Among the people that Emma Osmundsen, the Chair of this year’s UK Passivhaus Conference, is hoping to see at the conference are the sceptics – those who still can’t quite believe the levels of performance that Passivhaus buildings deliver, or who think these must come at a high cost.
Passivhaus buildings are designed and constructed to a standard that was developed in Germany. They provide a high level of occupant comfort while using very little energy for heating and cooling, and can be certified through a quality assurance process. “Post-occupancy and monitoring findings for UK Passivhaus buildings going back for the last 25 years provide plenty of evidence to demonstrate that the standard works,” says Osmundsen, Shadow Director (Development) at Exeter City Council.
An early role in social housing
The numbers and popularity of Passivhaus buildings has grown steadily in that time, despite there being no ‘top-down’ requirement for the standard to be used. Early adopters were interested individuals – often architects or environmental enthusiasts – and social housing developers who quickly identified the benefits in terms of a retained housing asset with energy and cost savings for tenants.
“Passivhaus has grown purely from a grassroots level,” says Osmundsen, “but we are now on the cusp of a shift in terms of scalability. In the last 2-3 years, private sector developers have begun to take an interest and we are seeing private homes in the market. The numbers are still relatively small in terms of the quantum of private housing coming forward, but the increased numbers of Passivhaus buildings and products in the marketplace could well be a catalyst for further growth in the sector.”
Stronger supply chain
The demanding standard to which Passivhaus buildings must be constructed does incur some additional capital costs, but as the sector grows these are being reduced and in some cases eliminated. “We are on our fourth generation of Passivhaus development here in Exeter,” says Osmundsen, “and building costs have certainly dropped from where we started 8 years ago. This is because we now have a much stronger supply chain in the UK, which is driving down the costs of a lot of Passivhaus components, particularly windows and doors.
“When we are developing numerous Passivhaus homes on a number of sites, we are able to deliver them at more conventional build costs, but for smaller scale developments you will typically still pay a slight premium in terms of a capital cost. This, however, is easily mitigated by reduced life cycle running costs.
Badge of quality
“We are also seeing more and more people asking about Passivhaus,” says Osmundsen. “Many have concerns about quality, particularly in view of recent evidence that some volume housebuilders are not delivering homes that are built to last. People want well built homes that are fit for purpose and safe and healthy. The Passivhaus standard is very much seen as a guarantee - a kind of ‘Mercedes Benz badge’ - of quality”.
Despite this recent growth in the Passivhaus sector, homes of this standard are not easy for private buyers to find because there are not still enough being built for the private housing market. So, another group of people that Emma Osmundsen is particularly looking forward to greeting at the forthcoming conference are the students – both those who will be the clients of the future, and the designers and engineers who will deliver the high quality, low carbon, reduced running cost homes of the future.
“To deliver buildings to this standard,” she says, “you need construction professionals who fully understand the different level of sequencing needed in terms of how you construct buildings, and the need to integrate architectural design with mechanical and electrical systems.”
Getting to the nitty gritty
The future is very much the theme of the conference, with an impressive line-up of speakers discussing Passivhaus’ role in delivering energy-efficient building solutions to meet zero carbon targets. It will also cater for those who are now considering or are already involved in Passivhaus projects, getting into the nitty gritty of detail and best practice with tech tasters delivered by Passivhaus professionals. These will include tips and tricks on designing out overheating, maintaining quality assurance on site, and successfully delivering complex and large-scale schemes.
The 2017 UK Passivhaus Conference is on 24 October at the Business Design Centre in London.