United Kingdom

ATTMA Authorised Air Tightness Testing Companies

ATTMA are approved by Governments in England, Northern Ireland, Scotland and Wales. ATTMA is listed in the relevant Building Regulations as an authorised competence persons scheme for the air tightness testing industry.
All members of ATTMA are independently audited and certified, with a scope covering air tightness testing to the ATTMA Technical Standards (TSL1 &/or TSL2) and BS EN:13829 (2001), demonstrating knowledge and understanding, which enables them to test both commercial and domestic developments in accordance with relevant building regulations.

The List of Members is shown below:

EA Calculator Only Authorised to carry out Envelope Area and Volume calculations but is not authorised to test
Level 1 Air tightness tester able to test dwellings and non-dwellings up to 4000m³ gross envelope volume, tested as a single entity with a single blower door fan.
Level 2 Air tightness tester able to test both Level 1 and large buildings up to 80,000m2 external envelope area and/or up to 15 storeys tall. Level 2 testers are able to test buildings defined in Level 1.

NOTE – All Level 2 testing companies are required to have at least one candidate that has the ‘+EA’ level.

Level 3 Testers who have been assessed for a higher level of expertise can test Large, Complicated and High Rise (LCHR), phased and zonal hand-over buildings. Level 3 testers are able to test buildings as defined in Level 1 and 2. *Presently, Level 3 is not enforced and therefore Level 2 testers are authorised to carry out Level 3 tests. Tests with a total surface area greater than 80,000m2 must be witnessed by an ATTMA authorised auditor*
Suspended Testers who have been temporarily removed from the scheme for failure to comply with the scheme rules or companies that have failed to pay the scheme fees. These companies are NOT currently authorised to test under the ATTMA scheme.
+EA Testers with +EA are competent to carry out envelope area calculations to Level 2 / 3 on behalf of their business. Companies cannot operate at Level 2 or 3 without either an EA Calculator or an engineer with +EA attached to their status.
+PH ATTMA members who are authorised to carry out testing for Passivhaus Buildings. Members who carry out Passivhaus tests follow the ATTMA / Passivhaus Trust joint standard TSL4. Members with the +PH qualification are authorised by the Passivhaus Trust to conduct air tightness tests.



Any queries regarding current membership status should be directed to Barry Cope (ATTMA Scheme Manager)