Services / Air Tightness Testing

Air Tightness Testing

Air tightness testing is a requirement for many new domestic properties to be compliant with Approved Document Part L of the Building Regulations (Conservation of Fuel and Power).  The Air Tightness Test checks the “air permeability” of the building fabric.  Matt will seal all means of building ventilation (i.e. vents, fans etc.) before using a specialised fan door to either pressurise or depressurise the building.  The building is then measured for air infiltration through gaps and cracks in the building fabric.  A building with more air leakage will be more difficult to heat and keep heated.

Our Air Tightness Tester Matt has been a BINDT (British Institute of Non Destructive Testing) registered tester for 4 year and is able to provide quotations for tests and general advice on achieving good building air tightness.

Prior to contacting us please briefly read through the below checklist to better understand what can be expected.

When to Test
Buildings are tested at a completed stage, although ideally prior to final floor coverings being installed so remedial works to improve the air tightness can be carried out if required.

Before the Test:

  • Building Plans –Matt needs a copy of the building plans (pdf or hard copy) prior to the test to carry out calculations of the building envelope.
  • Design Air Permeability Figure – The figure the building needs to achieve.  Available from the Design SAP or Building Control.

On the Test Day:

  • Ensure water and electricity is on.
  • Building should be unoccupied ideally.
  • All heating appliances are turned off.
  • The tester will be responsible for sealing all vents and extract fans.
  • The tester will be on site for 2 hours on average. Some developers prefer to be present during the test so sources of air leakage can be discovered and remedied with sealant where practical.
  • NOTE: Testing may be cancelled if wind speeds exceed 12mph.

Post Test:

  • Results provided same day verbally.
  • Report provided within 3 days.
  • Results can be forwarded to Building Control and SAP/EPC Assessors on your behalf if requested.

Developments with similar buildings may only require a sample of the buildings to be tested instead of every one.  Please contact us to discuss the sample that needs to be tested as this can vary depending on Building Control requirements.