If you’re a building contractor or one of the trades working on a Passivhaus for the first time, it can seem pretty daunting and unfamiliar. Most of the building contractors and other trades we’ve met on our various projects hadn’t worked on a Passivhaus build before.
If you’re working with us on a Passivhaus build, we’ll be able to guide you in getting the groundworks ready for our timber frame, and give you advice on finishing off afterwards, so that the airtightness of the frame is maintained.
A builder’s point of view…
Building contractor Sam Nelson began working on Passivhaus projects recently, after 40 years in traditional build methods. Here, Sam shares his advice for builders embarking on a Passivhaus build.
“If you’re a builder starting out on your first Passivhaus, throw away everything you did before. The whole set-up, from preparing the bases to finishing off, will be completely new to you. Even after 40 years in the building trade, I’ve been on a learning curve since I started doing Passivhaus builds. One example is airtightness. We’re taught to build air flow into houses, but it’s the opposite with passive houses, where you’re trying to get them as airtight as you can.
“My advice to any builder is to come into this with an open mind and embrace it. With Eden Insulation, I’ve been able to work alongside them and I’d also recommend getting an architect who understands the Passivhaus system.
“As a contractor, one of the biggest benefits of Passivhaus construction with a timber frame is that you don’t lose as much time because of the weather. Eden Insulation erect the frame generally within two or three days so you can have people working inside after that short space of time, whereas if you’re building with blocks you’re waiting weeks before you get to that stage.
“One of the biggest responsibilities for a building contractor working on a Passivhaus is getting the base right. It’s not like a traditional footing. The base has to fit the frame perfectly. There aren’t the same tolerances that you’d have with traditional building. I use a system called Isoquick to create an insulated foundation. It’s like constructing a huge insulated swimming pool that the concrete is then poured into. One of the challenges is making sure the level of the concrete is identical to the top of the Isoquick, as the frame straddles both. You have to be spot on in where you bring the services up in the base as well. It’s not hard, as such. It just takes a lot of attention to detail.
Getting everyone on board
“Once the frame is up, the hardest thing is getting all the trades on site on board. You have to drill through the frame in places, to fit outside lights and other services, so the challenge is making sure all the right airtight seals and grommets are used. As the main contractor, it’s my responsibility to go round and make sure there are no breaches in the airtight envelope.”
Resources for builders
The links below will give you to some useful information about building passive houses, from getting the foundations right, through to finishing off.
Eden Insulation restored my faith in timber-frame construction after a bad experience before. I knew their frame was in a completely different category as soon as I saw the panels arriving on the wagon. The materials they use are far superior and the panels were really well made. Putting it up went like a dream.
I’ve found them very easy to get on with on site. They’re really well organised and very knowledgeable. I was from a traditional building background and Eden Insulation have a lot more experience of Passivhaus building and were always on the end of the phone if I needed advice. They’re always open to any suggestions I’ve had and are always trying to improve. I can’t speak highly enough of them.
Watch as Sam celebrates achieving one of the highest airtightness readings ever recorded in the UK >>