Advertisement
Advertisement
Passivhaus shows up sustainable code failings
23 January 2009
The world’s leading energy-efficient house design fails to measure up to minimum Code for Sustainable Homes standards, a sustainability consultant has alleged.
Richard Hodkinson of Richard Hodkinson Consultancy tested the German-designed Passivhaus against the code and found it did not even meet level three – the minimum standard for today’s new-build housing association homes – because of the way the British standard measured energy performance.
This is despite the fact that the standard set by the Passivhaus Institute is increasingly being seen by the industry as a better way forward for new housing than the code and is actually so tough that no UK houses have been certified under the scheme.
Hodkinson carried out his self-funded informal study in spring 2007 when it was reported that Passivhaus could reach code level six. Houses built using the method have very good levels of insulation. Hodkinson said the problem was likely to be due to “the constraints of the Standard Assessment Procedure (SAP) on which the code is based rather than the constraints of Passivhaus.
“Passivhaus emerged from a really robust piece of research and development,” he said. “My concern is a lack of real research has gone behind the updating of SAP.”
Readers' comments
The AECB has been saying similar things for some time. The AECB Carbonlite Programme promotes the Passivhaus standard and methodology. In particular the Association has carried out a detailed comparison of PHPP and SAP which shows the problems with SAP when used to design/assess low energy buildings. The report has been taken very seriously both by BRE and Government. It can be downloaded from here.
Good article. Good to see such views being aired in the mainstream.
The SAP PHPP differences that Chris flags up are part of the problem and could be fixed given the will but my concern is with the whole CSH approach. Percentage reduction, emphasis on carbon before energy etc as flagged up on these pages in the past.
I felt so embarrassed to be British at the last Passivhaus conference when it was announced that all new UK houses will be zero-carbon from 2016 - why wasn't I proud of our political and technical superiority, why were people smiling??
Points well made. But, despite Chris saying that 'the report has been taken very seriously both by BRE and Government' the Government clearly hasn't taken it seriously enough.
Why? Because, despite SAP being deeply flawed, the Government have used it to model the effectiveness and costs of various technologies in Annex E of their current consultation on the definition of Zero Carbon Homes - http://www.communities.gov.uk/planningandbuilding/theenvironment/zerocarbonhomes/.