FAQ's
Do all new Dwellings need an Air Test?
All depends when the successful application was submitted and building work started. This will vary dependant on location and is not something that Adept Air ltd will advise on.
If a dwelling falls within the scope of Part L 2026 section
6.5 An air pressure test should be carried out on every new dwelling.
From the same document Table 3.1 defines a maximum air permeability 8.0 m3/(h·m2)
What air permeability level is required?
For both dwellings and non-dwellings, the maximum permitted air permeability is 8.0 m³/(h·m²) at 50 Pa.
If your building development falls within the scope of Part L 2026, the maximum air permeability is 8.0 m³/(h·m²) at 50 Pa, as shown in Table 3.1.
The previous Building Regulations, Part L the 2021 edtion incorporating 2023 amendments, also set the maximum air permeability at 8.0 m³/(h·m²) at 50 Pa, as shown in Table 4.1. Non-dwellings with a total useful floor area of less than 500 m² may not need to be tested if the default air permeability value of 15 m³/(h·m²) is used when calculating the building primary energy rate and building emission rate. However, you may still choose to have an air permeability test, as achieving a lower value than 15 m³/(h·m²) could help reduce pressure on other development costs.
Earlier versions of Part L allowed higher maximum air permeability values, but my understanding is that the transition period has now ended. To be sure, please check with your local Building Control body to confirm whether any local requirements apply.
Can Adept Air ltd find all the leaks?
A pressure test can provide useful guidance on the likely size and number of air leaks. Where possible, Adept Air ltd will use a thermal camera or smoke machine to help locate them.
Can Adept Air ltd repair the leaks?
Adept Air ltd does not carry out repair work. Once leaks have been identified, the most suitable person to fix them is usually the relevant trade professional. For example, a poorly fitted window should be repaired by a FENSA-qualified glazier, while an issue around plumbing would normally need a plumber.
Can a temporary fix be used?
This depends on the type of issue. For example, a broken pane of glass may be temporarily taped, but gaps caused by a poorly fitted window cannot be sealed as a temporary fix.
How long will the test take?
For a typical house, the test usually takes around 30 minutes. We will also carry out a quick check of the property size and make sure the building is ready and suitable for testing.
When can testing take place?
We can usually carry out testing from dawn to dusk, seven days a week. Before arranging an early or late test, please make sure that no one nearby is likely to be disturbed. The fan can be quite noisy, at around 80 dB, so immediate neighbours may not appreciate it running for 10–20 minutes very early in the morning.
What if the weather is very bad?
If the weather is very bad, please let us know as soon as possible so we can rearrange the test if needed. If the property is suitably airtight, wind will usually have only a minimal effect on the result.
Rain may also affect whether testing can go ahead safely, as the fan is powered by mains electricity.
Blower Door Fan vs Pulse
Blower door fans have been used successfully around the world for many years. Pulse is a newer technology, mainly used in the UK. Both methods should provide comparable results, and Building Regulations accept either approach.
One helpful advantage of a blower door fan is that it can support leak detection. The building can be continuously pressurised for smoke testing or continuously depressurised for use with thermal cameras, helping to identify draughts or unwanted ventilation more easily.
Adept Air ltd uses Minneapolis Blower Door™ Model 4 from The Energy Conservatory (TEC).
Who can carry out an air tightness test?
To provide a valid certificate, an air tightness test must be carried out by a tester who has been assessed as competent. ATTMA and Elmhurst currently train and assess testers to confirm they are qualified to test buildings for air tightness.
Competence is assessed for the individual tester, rather than the company. Adept Air ltd main tester and owner, Stephen Penny, is registered with ATTMA, and you can view his membership details here: Stephen Penny No.132465789
To make certain that your Air Tightness Certificate is valid ascertain that the tester themselves is still registered on either ATTMA or Elmhurst.
Who or what is ATTMA
ATTMA is a professional association that supports high standards in air tightness testing and air leakage measurement. Founded in 2002, it helps promote quality across the testing and measurement industry by providing members with clear guidance, auditing, and technical support.
ATTMA members must lodge their test data with ATTMA before an authorised test certificate can be issued. Only ATTMA members are authorised to issue ATTMA certificates, and the authenticity of any ATTMA certificate can be checked at www.attmalodgement.org.
All ATTMA members are authorised to test to ATTMA TSL1 or EN 13829:2001 for Building Regulations purposes. Members may also carry out non-domestic testing, such as commercial buildings, to ATTMA TSL2 or EN 13829:2001 for buildings up to 4,000 m³ in volume.
Additional membership levels allow suitably qualified members to test larger or more complex buildings.
You can find more information about ATTMA on their website.
Information needed for your quote
- Your contact details and the legal addresses needed for the contract.
- The location of the building to be tested. If a postcode has not yet been allocated, please let us know where the site entrance is.
- The air test result required. This is based on the air permeability allowance in the SAP/SBEM calculations, measured in m³/(h·m²) at 50 Pa, and the target air change rate.
- Floor and section drawings, so we can calculate the building’s volume and surface area. PDF copies are fine.
What Insurance does Adept Air ltd have?
Thomas, Carroll (Brokers) Limited provides both Public Liability & Professional Indemnity covered for up to £5,000,000 for Professional Indemnity and £2,000,000 for Public Liability claims.
What is the difference between ventilation and an air leak?
Ventilation is a planned part of the building design. It brings in fresh air for the people using the building and helps remove stale or damp air. An air leak, or draught, is unplanned. It can make a building feel less comfortable, increase the risk of mould, and lead to higher energy bills. Unlike proper ventilation, air leaks do not provide a useful benefit.
Is the equipment used reliable?
The equipment used for the air tests is UKCAS calibrated.
What happens if the air tightness test does not meet the target?
If the air permeability is higher than the target, Adept Air ltd can help identify the likely source or sources of the leakage. Once these have been found, the most suitable solution can be considered. If there is some flexibility within the SAP values, it may also be possible to adjust the required air permeability target. If the issue can be fixed permanently during the visit, a retest can usually be carried out straight away. If the repair takes longer, we can arrange a return visit for the retest.