NHBC director and Zero Carbon Hub chief executive Neil Jefferson questions whether the UK is as suitable for Passivhaus homes as its continental neighbours
Recently I’ve been reading the various responses to the launch of the NHBC Foundation’s Lessons from Germany’s Passivhaus experience – it seems to have stimulated some intense debate.
While the number of homes built to the standard in the UK are low compared to elsewhere in Europe, the Passivhaus movement has engaged a large number of vocal and passionate advocates. It captures people’s philosophical beliefs about building and, typically relying on mechanical ventilation and electric heating, offers a package of resources to achieve an overall low energy home.
The use of the word energy here is deliberate. Passivhaus uses energy as the measure with which to assess regulatory compliance. The UK uses carbon dioxide emissions. This difference means that when compared, it is gas rather than electrically heated homes that fare better when assessed against the UK’s Building Regulations. In Austria, for example, where Passivhaus has been more widely adopted, extensive use of hydropower and biomass yields a lower carbon intensity electricity grid than we have. In Germany, government support for the Passivhaus approach has enabled critical financial drivers to follow.
If you were to ask me whether I think we will see large numbers of Passivhaus certified homes in the UK, my response would be that it’s highly unlikely. It is a very prescriptive standard and in practice it can be difficult and expensive to achieve. But that doesn’t mean that I think the approach is irrelevant to the UK. The “fabric first” ideals of Passivhaus have already been incorporated into the Fabric Energy Efficiency Standard and the Code for Sustainable Homes. In addition, the attention to detail and inbuilt quality assurance procedures of the Passivhaus approach offer us a great learning opportunity, especially when considering how we ensure homes perform in practice as intended.
Neil Jefferson is a director of the NHBC and Zero Carbon Hub chief executive