A Passivhaus
Passivhaus is the gold standard in energy efficiency for a building.
Designing and building to achieve Passivhaus certification requires a whole-building approach, focused on high-quality construction, certified through an exacting quality assurance process.
Passivhaus homes are constructed, insulated and ventilated to the very highest standards so that the heat generated within is retained, requiring very little extra heating or cooling. To achieve Passivhaus Certification the air permeability rating must be a maximum of 0.6m3/(h·m2)@50Pa. In practice, this means that in 1 hour, for every square metre of surface area, the building can only lose just over half a cubic metre of warmed air through leaks in the fabric.
Download the Good Practice Guide to Airtightness from the Passivhaus Trust
Passivhaus EnerPHit
The EnerPHit standard is a Passive House standard intended for refurbishment projects. It allows for greater latitude in building standards to accommodate retrofitting challenges, while still achieving the superior comfort and performance of a new build Passivhaus home.
To achieve the Passivhaus Standard in the UK typically involves:
- accurate design modelling using the Passive House Planning Package (PHPP)
- very high levels of insulation
- extremely high performance windows with insulated frames
- airtight building fabric
- ‘thermal bridge free’ construction
- a mechanical ventilation system with highly efficient heat recovery