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.”