Many people would reasonably assume that new homes are automatically built to a high level of energy efficiency, maximising the use of modern technologies to give optimum energy performance. Whilst many statistics will demonstrate that yes, new homes are usually more efficient than old, there is a huge lag between what building regulations specify as a requirement vs the possibilities of just how efficient your home could be.
Two of the core Passivhaus (Passive House) principles are super-insulated and airtight structures allowing buildings to be heated by capturing and retaining the free heat available from the sun.
In its airtightness test last month (a test which involves evacuating and pressurising the building to check for air leaks), we were delighted (and a little bit relieved!) when Anchorage Passivhaus scored an impressive airtightness of 0.44, well below the Passivhaus standard of 0.6 meaning it is well on its way to Passivhaus Certification.
Building regulations specify that any newbuild should meet an airtightness level of 8. Although the units of measurement differ slightly, this is around twenty times worse than the level we have achieved in our project, showing just how vast the chasm is between what building regulations specify and the energy performance that we are striving for in Passivhaus.
Given the complexity of the geometry in our cantilever and interlocking shapes at Anchorage, exceeding the airtightness goal to such an extent is a significant achievement. Well done to RDS Build!