Build Comply

Air Permeability Testing

Retrofit, Domestic, Residential, Commercial, Plenums, Smoke Shafts.

Are you looking for a Building Air Tightness Test?

Building Air Tightness Tests are also known as a air permeability, air pressure or air leakage test.

A building air tightness test is required to comply with Approved Document Part L1 and L2 of the Building Regulations, ensuring your building is air tight is essential.

Likewise, this too is paramount in a retrofit project.

Testing assesses the level of conditioned (heated or cooled) air leakage. This is known as infiltration, evidently felt as uncontrolled ventilation. By ensuring that the building meets or exceeds the air permeability rating specified in a design stage SAP or SBEM Calculation, air testing guarantees energy efficiency and performance.

Our testing is routinely carried out using a blower door. Following the methodology to ATTMA standards in line with CIBSE TM23 or ISO 9972:2015

Are you ready for your Air Test?

Click here to find our Air Permeability Site Status Checklist covering common leakage area preparation and recommended sealing

Along with your air testing we can provide a full suite of diagnostics. Thermal imagery and smoke testing coupled with a depressurisation and/or pressurisation test can help massively identify problem areas.

Furthermore, we offer full reporting detailing suggestions for rectifications to reach target leakage rates.

If your project requires air testing to meet a design air permeability for SAP Compliance, Building Control request, New-Build or Retrofit, feel free to reach out to us at 01621 493594 or visiting our contact page. Building Compliance Testing commits to providing a quote within 24 hours. Upon acceptance we can dispatch a tester to your site within 48 hours for Air Testing in London and Home Counties. Secure Expert Professional Air Testing services today by booking with us.

Testing and ATTMA Certificate for as little as £145+VAT

Have a project in mind? Let’s get to work.

What is Air Permeability Testing?

Air Permeability Testing – also know as Air Tightness, Air Leakage, or Air Pressure Testing – measures the amount of air escaping through cracks and gaps in the building envelope. This is known technically as air infiltration.

A more airtight building results in lesser heat loss, therefore improved energy efficient by reducing heating demand whilst also improving comfort for the occupants with reduced noise ingress, cold draughts and temperature fluctuations.

Air tightness should be considered along side ventilation, summertime overheating, thermal bridging and overall construction detailing of the building envelope, more specifically the junctions of walls, floors and roofs.

In summary, air permeability testing is a regulatory test procedure to measure unwanted air leaks in a building to ensure compliance with energy efficiency targets in new-builds and a drive for decarbonisation in existing buildings.

Do I need a Air Permeability Test and why is it important?

Approved Document Part L1 of the Building Regulations mandates air tightness testing for all new dwellings and the result is used to inform building specific emission targets and the generation of Energy Performance Certificates.

Non-domestic commercial buildings with floor areas of greater than 500m2 are mandated to carry out air testing also, however much like with domestic retrofit, an air permeability test can be used to help assist accurately model a building.

Verifying higher airtightness with an air permeability test informs accurate heat losses and therefore increases in energy efficiency. The tighter the air tightness (the lower the result), the lower the heat loss, lower energy demand, greater the thermal comfort, benefiting both the occupants and the drive for net-zero homes by 2050.

The Air Test

At Building Compliance Testing an air test is typically carried out by a single engineer using a UKAS calibrated blower door system. The system is essentially a fan mounted within a canvas, that’s installed within an external opening, such as a door or window. The fan is controlled by a fan speed controller, and a number of tubes connected to a multi-channel manometer, used to measure pressure differential.

Before and after the test, building static pressures, internal and external temperatures and barometric pressures at recorded which is read and inputted into a software to generate a result.

Generally during this time other trades can remain within the building so long as the external envelope remains closed (external doors and windows) and internal doors open.

Typically the test takes between twenty minutes to a couple of hours. However, this all depends of the size of the building, the test locations, the ability to create stable pressure in the building and unfortunately the controllable influence of the British weather.

An alternative approved testing methodology is Pulse. You can learn more about Pulse Testing by clicking here.

Air Pressure Testing Standards

In Approved Document Part L1 of the Building Regulations, the process of assessing a building’s air tightness is commonly referred to as Pressure Testing. This methodology, as defined in ATTMA Technical Standard 1, is based on internationally recognised standards like BS EN Standard ISO 9972:2015. Likewise there may be a need to test to the revised CIBSE TM23.

For new dwellings, as stipulated in Approved Document L1, airtightness tests are mandatory for all new build dwelling. Compliance with Part L1 necessitates that any tested dwelling achieves an air pressure test result (known as a design air permeability) of 8m³/h/m² or less at a pressure differential of 50 pascals for Building Control.

ATTMA has four different levels of testing which have varying degrees of required competence and changes in the test standard.

Level 1 – A single dwellings and small non-dwellings up to 4000m2
Level 2 – Larger and more complex buildings exceeding 4000m2
Level 3 – Large, complex, high-rise, phased and zonal handover buildings
PH – Those members authorised to carry out testing of Passivhaus buildings

Air Testing Equipment

As expected, the equipment used for Air Permeability Testing is highly specialised and demands frequent and rigorous calibration to ensure precision. As a result, equipment from Building Compliance Testing is calibrated by a UKAS approved laboratory to guarantee accuracy during on-site tests. Building Compliance Testing is registered with ATTMA, subject to regular audits to uphold high standards and accuracy. If you’re uncertain about whether your project necessitates an Air Testing, we can provide guidance. We also offer complimentary, no-obligation quotes at highly competitive rates for projects of all sizes.

Building Air Tightness Test

To summarise a building air tightness test assesses energy performance by measuring air volume escaping per hour per square meter at 50 Pascals. It identifies gaps and cracks in building envelopes, reducing heating or cooling costs. Using a blower door system, the test takes 20 minutes to a few hours.

Building Compliance Testing has you covered if you are considering a building air tightness test. Our ATTMA qualified air tightness testers offers design reviews, site inspections, and training for compliance. Additionally, we can provide diagnostic services like smoke testing and expert Passivhaus testing.

We offer a range of testing and compliance services – the compliance package – to ensure your building project meets the required standards. Contact us today to discuss your specific project requirements and learn how we can provide all your building compliance testing under one roof, from concept to completion.