Airtightness
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Air Tightness Testing


Commercial and domestic air tightness testing from BM TRADA

As a UKAS-accredited and BINDT registered member of the Air Tightness Testing and Measurement Association (ATTMA), we are independently approved to carry out air leakage testing of all commercial and domestic building types.  Testing is conducted based upon ATTMA Technical Standard 1 (required by the current revisions of Building Regulations Approved Document L1 & L2), CIBSE TM23 or EN 13829. 

What is air permeability?

Air permeability is the uncontrolled flow of air both into and out of a building through gaps and cracks.  Uncontrolled air flow accounts for a large proportion of the energy wasted in buildings.  Achieving improved air tightness is a key factor in building contractors meeting the Government’s targets for reduced carbon emissions and improved energy efficiency.

Air tightness is a key requirement of Approved Document L Parts 1 & 2 of the Building Regulations for England and Wales, without which, Building Control will not provide a Completion Certificate.

Our air tightness testing services

We deliver a comprehensive air tightness testing service with no hidden extras. We provide added value by helping our clients to achieve ongoing improvement based on practical guidance and advice before during and after air tightness testing. We can also offer a more streamlined service to companies who wish to provide certain aspects of the air leakage testing process themselves. In addition, we can also provide sound insulation testing and energy ratings (SAP/SBEM), which is reflected in the cost.

Before the air test:

  • Office-based technical advisers for all our energy services (air tightness testing, sound insulation testing, thermography, energy assessments)
  • Design detail evaluation - a member of our air tightness team will review the details of the design with the client to spot potential problems at construction stage
  • Pre-test inspection – our air tightness technicians will conduct an inspection of the building to be tested to point out potential problems
  • Indicative air leakage testing, of components and/or sections of the building to provide an insight into the final air permeability performance of the building.
  • Identification of an air testing programme (where required) and discussion with Building Control as necessary
  • Liaison with site directly – our air tightness technicians will contact the site to arrange provisional air test dates, explain the process and preparation, confirm the plot is ready for air leakage testing and what needs to be achieved
  • Confirmation of the air permeability requirement, so we know if the test result is a pass or a fail on site and can help to address any issues.


During the test:

  • Envelope area calculations
  • Preparation of the building as required in ATTMA TS1 (where agreed in advance), including identification of potential air permeability problems
  • Air test results available immediately, certificates can be issued on the same day if requested (although not on-site)


After the test:

  • Diagnosis - identification of air leakage points, ideally on the day with the opportunity to resolve issues and repeat the air pressure test (where possible)
  • Smoke pens
  • Depressurisation
  • Smoke testing
  • Detailed report and certificates by email and/or post


We are also able to provide a number of air permeability training options.  See Air Tightness Testing Explained for further information.

UKAS accredited       ATTMA members

Contact Details


Graham Tomic

01494 569830

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