Air tightness testing in Cardiff

We provide air tightness testing across Cardiff and the surrounding towns of Newport, Penarth and Bridgend via our network of UKAS accredited air testing engineers. We have the ability to respond quickly to your project requirements and comes at the most competitive price.

We are also one of the few companies that are UKAS accredited to undertake both Air & Sound testing in compliance with Building Regulations Part L & E. This means we can undertake Air, Sound and Vent Testing Packages during the same visit, which provides our clients with substantial cost savings and improved on site co-ordination. Unlike many companies we do not subcontract our works.

Air testing to achieve satisfactory levels of air tightness became a legal requirement in 2006 in England and Wales, under Part L of the Building Regulations. Our specialist knowledge of Part L of the Building Regulations and the unique needs of our local clients means that we are Brighton’s most popular air testing and sound testing companies. We undertake air testing on all types of projects from single dwelling to the largest commercial buildings.

Air tightness testing is carried to check the air leakage that occurs through a buildings envelope. The air test checks amount of conditioned air that escapes or gets wasted through gaps or air leakage paths through the building fabric. If the building is more air tight, less energy will be being needlessly lost, thus lowering the carbon emissions of the building. Air tightness testing also shows how efficient a building is at retaining conditioned air which will also put less straight on your mechanical and ventilation system. Failing to maintain adequate air tightness can lead to up to 50% of heat loss from within a building to the outside atmosphere.

Air testing is mandatory in the United Kingdom and is governed by Part L of the Building Regulations, this split into two parts; for domestic properties Part L1A should be used and for commercial properties Part L2A should be referenced.

Most air tests can be completed in 1-2 hours although some can take much longer, if low air leakage rates are required to comply with Passivehaus standards etc. Also other factors such as the size of the property, how many apertures need to be taped over; however even on very large dwellings the duration of the actual air test should take no longer than 2 hours if the building has been adequately prepared.

We also offer a smoke testing service to locate the air leakage paths within a building envelope which can also take extra time; however this often allows our clients to seal and pass their building at the first attempt even if their building initially fails the air test.

It depends on the location and the number of tests that are required on each site; it can be as low as £75 plus VAT per unit if we are undertaking multiple tests. Please contact us at to obtain a no obligation quote along with some friendly advice for you project.

As a general rule, the nature of the current building regulations requires that all new dwellings achieve an air leakage of 5m3/hm2 or less. That is the air leakage rate per hour, per square metre of envelope area. An air test results between 3 – 5m3/hm2 would usually be acceptable by building control and your SAP assessor as a good and acceptable result, although you need to check each your designed SAP Assessment as there may be items within your buildings design that that may affect this figure as the dwelling may be struggling to meet its emissions targets and a low air leakage may compensate for other areas, either arising from poor design, or factors beyond the developer’s control.

The air tightness test is undertaken in-line with Part L and the ATTMA standard. The pressure differential is measured across the envelope of the building by means of the temporarily installation of a large fan inside a door panel. Thereafter, a range of static pressures and environmental readings are taken. The fan is switched on and the air pressure in the property is gradually increased or decreased and the differential pressure is recorded at each step. The total air flow required to achieve a pressure differential of 50 Pa is calculated and divided by the total building envelope area to provide the leakage rate in m3/h.m2@50Pa.

In all cases the more complete a development, the more likely it is to meet air testing requirements. When we send out our quotation we also forward a specific air leakage checklist to help our client prepare for the testing.

Basically if you meet the following criteria will generally have a much better chance of passing the testing at the first attempt.

a. The building envelope should be fully complete; this includes walls, floors and ceilings.
b. All doors and windows must be fully fitted and able to shut tightly against their seals.
c. All electric fittings must be installed and functional.
d. All mechanical fittings must be installed and functional.
e. Gaps within walls and floors must be sealed.
f. All service penetrations must be fully sealed through the building envelope.
g. Bathrooms and kitchens must be fully fitted and all service penetrations sealed.
h. All mechanical ventilation turned off with grilles sealed.
i. All trickle vents to windows and doors must be sealed.
j. All fireplaces must be sealed.
k. Ensure water is present in soil pipes.
l. 240v power must be available on site.