Air Tightness Testing for Dwellings

Building Regulations and Building Standards require all new dwellings/residential buildings to have an Air Tightness Test with a few notable exceptions. Air Tightness Testing is used to measure the amount of air which leaks out of the building through the building fabric. This can often determine the quality of a build.

Part L1A and L2A of the Building Regulations stipulate that all new dwellings must have a SAP calculation, which will be used to decide whether your building requires an air tightness test.  

When is an Air Tightness Test required?

This depends on the type of dwelling being built. For single units, an air tightness test should be conducted at the end of construction, before final approval is given. If your project involves multiple units then testing should be carried out during the construction of the first 25% of the dwelling type. 

Your property may also require an extract flow test, which is more cost-effective to carry out at the same time. 

What does the test involve? 

The 'blower door test' is the standard test for measuring the air tightness of a building. The process involves blowing air into the house via a specially made machine mounted in the main entrance of the house (pictured right). Thermographic equipment is then used to identify any leakage paths. 

In England and Wales, a dwelling must achieve a maximum air permeability result of 10 m³/(h.m²) in order to pass an air-tightness test. Section 6 of The Scottish Building Regulation requires a maximum of 7 m³/hr/m².

If the building fails to achieve the minimum score, the property will need to carry out corrective work in order to meet compliance. 

How do I arrange an Air Tightness Test?

Get in touch with Elmhurst Energy Services and we can signpost you to one of our reputable companies.