As climate awareness increases in the United Kingdom—and energy prices soar—interest in either building or retrofitting to the Passivhaus green building standard is skyrocketing.
“There are 1,500 Passivhaus buildings in the UK—and they have never been more popular,” writes The Guardian.
“It’s a way of ensuring that your building or home is very energy efficient, by reducing the energy demand—particularly for heating—down to very low levels while, at the same time, making sure the building is comfortable inside and has high levels of good indoor air quality,” said Jon Bootland, CEO of the Passivhaus Trust, the non-profit that awards the rigorous, energy-based construction standard in the UK.
Bootland told The Guardian the past 18 months have seen the number of projects in the Passivhaus pipeline surge.
“At the last count, there were over 7,000 homes in development,” he said, explaining that interest in Passivhaus buildings exploded when local authorities started declaring climate emergencies and setting carbon neutral targets. “If you’re trying to deliver net zero new-build social housing, one of the best ways to do that is to build a Passivhaus and then have some renewable energy provision locally, possibly on the site.”
Camden’s Agar Development illustrates the benefits Passivhaus can bring to social housing. Consisting of 216 council homes, the award-winning development is the largest Passivhaus scheme in the UK, and its residents now enjoy energy bills 70% lower than they were paying in their previous homes.
Any building pursuing Passivhaus accreditation in the UK must meet all standards required by the Passivhaus Trust, and “undergo a strict compliance process” with an accredited expert from start to finish.
“A true Passivhaus will always have a certificate to prove its status and your solicitor should be sent the paperwork during the conveyancing process,” notes The Guardian.
The accreditation process, plus costs that accrue from insulating and ventilating to a very high standard, mean Passivhaus homes typically cost between 4% and 8% more to build than a standard home.
The building materials are basically the same, Bootland noted, so “it’s the attention to detail, in terms of getting the design right, and the fact that the quality control onsite is more rigorous,” that make Passivhaus building more demanding. So a Passivhaus should be “only a tiny bit more” time-consuming and tricky to build than a standard house, he said.
While retrofitting to the Passivhaus standard is entirely doable, and will yield great benefits by slashing energy bills and increasing comfort, Bootland warned that process should begin with enlisting a certified Passivhaus consultant to examine the home and develop a solid plan.
Owners of damp and drafty older homes need to be particularly careful, he added, noting that “it might not be financially viable or appropriate to take a building like that to the full Passivhaus retrofit standard.”
“Definitely get expert advice. Don’t try to do it yourself,” he said.
“Green mortgages” with discounted rates or cashback provisions are available in the UK to fund new or retrofitted Passivhaus homes, writes The Guardian. “Green living” home improvements like triple-glazed windows and air source heat pumps are also eligible for cashback under various schemes.