Passivhaus is a low energy construction standard where the building requires very little energy for heating or cooling. To achieve this, the building must have excellent thermal performance with exceptional airtightness. The UKs first permanent Passivhaus show house, has been built by Potton using the Kingspan TEK® Building System. It joins four existing show homes at their Self Build Show Centre in St Neots and utilises Wraptite-SA (Self-Adhered) air barrier membrane, supplied by the A. Proctor Group.
Wraptite-SA is both vapour permeable and airtight, combining two important properties in one BBA certified solution for wall and roof applications. It’s unique vapour permeability allows the air barrier to be positioned externally, leading to a faster and more robust installation, with fewer penetrations for building services and structural elements.
As a Passivhaus standard show house, this project required a very low level of air leakage, making Wraptite-SA the ideal choice. This membrane significantly improves the building’s thermal performance by preventing lateral air movement, while ensuring a healthy building and living environment due to its high degree of vapour permeability.
The Passivhaus standard must be demonstrated by means of an airtightness test, carried out using a blower door. The air change rate must be less than or equal to 0.60ac/h (air changes per hour), under test conditions, to meet Passivhaus levels. At a recent Self Build Live event on the 4th March 2016, Potton managed to improve on their target of 0.60 ac/h (air changes per hour), to 0.5 ac/h!
For further information on the Wraptite-SA membrane, visit www.proctorgroup.com. You can also visit the Passivhaus at various stages of the build programme, visit www.selfbuildlive.com for details.