Part L1A of the Building Regulations – formal Air Pressure Testing to ATTMA TS1 issue 2 (BS,EN Standard 13829:2001) standard, to comply with approved document L1 of the Building Regulations including all associated test report(s) and certificate(s).

An air tightness test is often completed as part of a SAP Calculation to further contribute to the energy efficiency of the SAP Calculation and EPC. 

All new dwellings (Part L1A) need to have an air test score recorded within the SAP Calculation to help the dwelling comply with the TFEE (Target Fabric Energy Efficiency) target. Dwellings that are not individually tested will need to have an air test score entered into the SAP calculation from a similar house type on site with the addition of a 2.00 confidence factor added to the test result.

Air movement throughout a building often contributes more to energy efficiency than the insulation values of the walls and windows.  As we control the inflow of cold air and outflow of warm air, we minimise wasted heat energy and subsequently can result in lower fuel bills.

To perform an air tightness test, the building should be complete and all external and internal mastic works should have been completed, any holes that have been made in the fabric of the building also to be sealed. The test then comprises of de-pressurising the building, and producing a result in order for the EPC to be completed.  

Air Test Checklist:

Please click here to download.

How we can help:

Our experienced Air Testing Engineers carry out a large number of tests on a weekly basis, and therefore, if a failure occurs they have the experience and knowledge to identify Air leakage paths within the construction. If the property fails the Air test, the Engineer will stay on site for a reasonable time period to rectify any minor issues, otherwise advise will be given on site to the site manager, and a retest booked.

The Air Pressure tests are carried by ATTMA certified Engineers, and all the equipment used is regularly calibrated to UKAS accredited standards.

Get in touch:

Our team are here to answer any of your queries, or if you would like a FREE quotation, please give us a call on 0333 5777 577 or fill in our contact form and we will get back to you.



Get in touch:

Our team are here to answer any of your queries, or if you would like a FREE quotation, please give us a call on 
0333 5777 577 or fill in our contact form and we will get back to you.





Top Tips: check seals

  • Seals between floors and wall, and walls and ceilings.
  • Seals around your loft hatch.
  • Around services i.e. pipe work.
  • Behind fitted units or behind bath and shower tray panels.
  • At the junctions of external walls and floors.
  • Around windows and doors.