The Passivhaus standard can improve all sizes and types of projects - I’ve seen the evidence
I’ve always been a supporter of the Passivhaus standard for buildings, and not just because it’s an effective route to energy efficiency. The main attraction of Passivhaus lies in its simplicity and focus, and the way this allows architects, engineers and contractors to take very different and flexible approaches to delivering projects.
This creates much more scope for innovation and cost reduction by project teams, in ways that fit with their existing working styles and business models.
For example, last month I enjoyed looking at the projects showcased at the Passivhaus Trust Awards in London, and was struck by those in the Cost and Buildability category.
The three finalists illustrated three completely different approaches to construction and innovation, while all sharing successful customer outcomes by achieving Passivhaus energy standards.
The first project showed every sign of having been a labour of love by a highly committed architect. It was a private house, and their story was one of delivering Passivhaus through finding imaginative low-cost solutions to every obstacle as they went along. I was not quite Heath Robinson, but certainly the classic British innovator delivering quality and performance at a low cost against all the odds. I may be being unfair on the project, but I suspect delivering Passivhaus at scale using this kind of approach would depend on perpetuating a culture of poorly paid but nevertheless highly committed architects and designers, which would surely be hard to find anywhere in the world.
Efficient design of the construction process is something which the fragmented nature of the construction industry usually makes very challenging
In contrast, the second project applied modern methods of construction – an offsite timber-framed system designed for simplicity and ease of assembly – to enable low-cost delivery of social housing units using relatively unskilled labour.
Passivhaus performance was delivered through design – not just building design, but more significantly design for manufacture and build. Efficient design of the construction process is something which the fragmented nature of the construction industry usually makes very challenging. Passivhaus reduces this challenge because the 15 kWh/m2/yr heating demand target creates coherence and objectivity that is missing in many projects.
Off-site manufacturing is not for everyone, though, so it was encouraging to find the third finalist was a traditional new-build social housing scheme where the developer had simply decided to adopt Passivhaus standards part way through the build.
In this case a competitive outcome was delivered by a traditional design team simply thinking through the project in a slightly more rigorous way and adapting the working methods and approaches they used. The outcome was lower whole life costs than equivalent buildings built to building regulations, as well as much better and healthier homes, indistinguishable in external appearance from any other contemporary housing scheme.
Which approach won? I’m not going to tell you, because I think the message isn’t that any one of these approaches is better than any other: the main message is that well-designed standards like Passivhaus can work well in many contexts, and are well worth exploring whatever your working style and business model.
Matthew Rhodes is managing director of Encraft