JOT Energy

Airtightness Testing

A required test under building regulation for new builds, airtightness testing can pinpoint problem draughts in any building, helping to identify areas for significant improvement in energy efficiency.

passive house

What is airtightness testing?

An airtightness test is carried out to identify uncontrolled leakage in a building. It essentially indicates how drafty a building is to remediate the effects of heat loss through building fabric elements.


When do I need an airtightness test?

Under TGD L 2019, all new domestic and commercial buildings need an airtightness test when the installation is complete. To satisfy the building regulations, the airtightness test result must be less than 5 m3/hour/m2 @ 50 Pascals. You might also get an airtightness test when doing a deep retrofit of a building to identify the most drafty areas. It can be beneficial when coupled with a smoke test or thermal imaging survey to determine where you are losing heat and if windows are poorly sealed


How do I know if my building is too airtight?

If a natural ventilation system presents an airtightness test result of less than 3m3/hr/m2, your home is too airtight. A mechanical ventilation system may be required to help deliver adequate fresh air.