An Introduction to Air Tightness Testing
Parts L1a and L2a

The requirement for air tightness of buildings in the UK is driven by the Building Regulations. In England, Wales, Scotland and Ireland, the majority of new building projects will require air testing.

The Airtightness Testers Association (ATA) is a committee within The British Institute of Non-Destructive Testing (BINDT) that is dedicated to promoting excellence in domestic air tightness testing.

The BINDT L1a scheme for the testing of dwellings consists of individual members who have been registered by BINDT as part of a registration process. Each individual must complete the necessary competency checks as required by the Building Regulations approved document, Part L1a. All members of the ATA are registered with the BINDT L1a scheme.

Please click on the ATA logo for further information on the BINDT L1a scheme, the ATA and for an up-to-date list
of L1a individuals registered to test dwellings. 


The Air Tightness Testing and Mea
surement Association, or 'ATTMA' as it is better known, is a special interest group dealing with air permeability of all building types following the requirements in the Building Regulations approved document, Part L2a.

ATTMA is comprised of organisations that are experienced UKAS-accredited air testing bodies who have undergone further technical appraisal by ATTMA.

Please click the ATTMA logo for further information on Part L2a, ATTMA and for an up-to-date list of member organisations available for the testing of all building types.






Further clarification and information for building control, builders etc

Below are sample logos issued by BINDT


All individuals registered to test dwellings should display their own 'official' BINDT logo. This will show their name and individual registration number. To ensure the individual is still registered with the scheme you can cross reference the information with the list of individuals registered to test dwellings. Click on the L1 logo to see the up-to-date list.











Companies accredited to test dwellings/non-dwellings should display their own 'official' BINDT logo. This will show the company name and can be crossed referenced with the list of members accredited to test dwellings/non-dwellings. Click on the L1/L2 logo to see the up-to-date list.












PLEASE NOTE: BINDT IS NOT RESPONSIBLE FOR CONTENT ON ANY OTHER WEBSITE RELATING TO ATTMA/AIR TIGHTNESS TESTING.