Air Permeability Building Regulation Advice From A Test Engineer

[vc_row uxb_theme_class=””][vc_column uxb_theme_class=””][vc_column_text]When you design or construct a new residential dwelling, it’s energy consumption is. Air leaks can reduce the energy efficiency of a building as it may require more energy to heat and as a result increase the dwelling’s carbon footprint.

Air permeability testing is done to verify the robustness of a property’s building materials and workmanship, and that wok have been done to reduce uncomfortable drafts and

Air permeability testing is also a key component of SAP Assessments, which are used to determine the energy performance of a residential building. Air leakage tests are also applicable for commercial buildings, which follow SBEM Calculations.

Here are 12 pieces of advice for the best results of controlling air leaking from one of our senior engineers, Marc.

Decide from the get-go how you are going to deal with air tightness

“Set early targets. And make sure all stakeholder tradesmen take part in a pre-start toolbox talk. Everyone involved needs to be aware that the plan is to create an airtight building.”

“Ensure that all necessary SAP calculations have been made and that all results have been accurately recorded for every property tested. You can find this number on the SAP report (under, q50, DAP, or Air Permeability).”

You may find it helpful to mark out an airtight barrier early on. Draw a line connecting all areas which separate heated elements from unheated elements. As an additional control measure, why not appoint a single focal point on all air tightness issues for concerned parties”.

Carry out regular inspections throughout the building program

“To counter the effects of shoddy workmanship, consider installing an inspection schedule during construc-tion. You will want to avoid test failures at all costs since these lead inevitably to costly remedial work.”

One common source of leakage happens when cavity walls are breached at the time of construction – commonly in the vicinity of floor joists. Be sure to use industry-standard fixings to prevent this”.

Take care with dry lining

“Plasterboard put in place with the dot-and-dab method can prove problematic. Undetected leakage in brick or block may leave an unwanted path from board to floor slab. Two solutions spring to mind. The first is to initially parge-coat the wall. The other is to lay continuous lines of adhesive round board sides, and socket cut-outs.”

Seal all pipework to prevent air leakage

“Be sure to seal all waste and supply pipework at the exact places where it passes through floors or walls. Use approved, gunned sealants (for bigger gaps use pre-compressed strips of foam, which are flexible and expandable. Avoid foam — it shrinks too readily, breaking the seal. There are flexible foams on the market, specifically tested for use in airtight projects”.

Doors and windows

“As an expert in the field, I see plenty of door and window frames that have been incorrectly sealed. Save yourself a lot of heartaches —always use suitable seals and sealants to avoid gaps wherever they are located.”

Radiator pipework

“Underfloor manifolds or radiator pipes aren’t always sealed when the floor is screeded. This problem is often compounded by covered gaps with flooring. Also, radiator pipes often pierce walls behind a radiator. This is a very difficult area to access and check.”

Make sure you include eaves, loft hatches, and cupboards

“In homes which include roof space rooms, it is common to find air leaks at the eaves, around cupboard doors, and in loft hatches. Such rooms are often added later, effectively partitioning unheated space from living space proper, so it’s best to seal these as efficiently as any external door or window”.

Pay particular attention with light fittings

“Take care to properly fit all light switches and fittings, electrical appliances and plug sockets before being tested, since temporary sealing of these components is prohibited. Improper fitting runs the risk of air loss leading to poor results.”

Seals around services

“All modern homes are serviced. So be aware that pipework for water, drainage, and gas; flues servicing boilers, and areas housing electric cables commonly leak – we regularly come across leakages in meter boxes”.


Bathrooms offer the perfect opportunity for air leakage. The main culprits are bath panels and pipework. Ensure that all avenues for air leakage are adequately sealed before attaching bath panels, covers for vani-ty units, extractors, and anywhere that requires boxing-in.

Skirting boards must be sealed

For optimum efficiency, seal all skirting boards top and bottom, with silicone sealant. You should not rely on traditional carpets or other floorings to stop air leakage.


For best effect, ensure that kitchens are finished. This includes all appliances, any required boxing-in, and the full installation of extractors. It is no surprise that in common with bathrooms, leakage in kitchens is often detected where there is pipework. Don’t forget the cavities behind kitchen cupboards!

At Briary Energy, we provide fast and effective air permeability testing services for new builds that can contribute towards your development’s SAP calculations. Our fully qualified experts will guide you through air leakage testing and help identify improvements for your development.[/vc_column_text][/vc_column][/vc_row]