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Building Contractors & Architects

If you’re a building contractor or one of the trades working on a Passivhaus or Timber Frame project for the first time, it can seem pretty daunting and unfamiliar. Most of the contractors and trades we’ve met on our various projects hadn’t worked on a Passivhaus build before, but upon finishing the project realised they had nothing to worry about in the first place. Read on to hear from an architect we wrok with regularly, and from a  builder who experienced his first Passivhaus build with us!


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.


We have many years’ experience of building properties with very high standards of insulation continuity and airtightness, including to Passivhaus standard.

Multiple homes built with our timber-panel frames have obtained Passivhaus certification, including the first certified Passivhaus in Cumbria. In all these builds, we’ve achieved levels of airtightness that are better than the minimum requirements for Passivhaus.


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.


First base


“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.”


An Architect's Point of View

Andrew Yeats (Eco Arc), a certified Passivhaus architect, has worked alongside us on various builds over the past few years. Here are his thoughts:



"It’s been a huge breath of fresh air working with Stephen and his team at Eden Insulation.

 I’ve worked with some other timber frame fabricators in the past and it’s been a struggle to get them to understand building to a Passivhaus standard.


Eden Insulation have proficiency in Passivhaus detailing – from continuity of insulation and reducing cold bridges, through to minimising the frame factor and delivering a high level of airtightness.


As a Passivhaus architect, working with Eden Insulation has reduced the stress on me because they are always ahead of the game, and it has reduced my workload, because I don’t have to essentially train another company to build a frame to Passivhaus standard."

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