Part L: Will Pulse Testing replace Air Leakage Testing?

In this series of articles, we aim to answer some of your questions about the upcoming changes to Approved Documents L and F, SAP methodology and the Future Homes Standard.

Current proposals suggest these regulations will be coming into force in England from October 2020. Contact us with your own questions about the regulation changes, or to discuss our training seminars and workshops.

What is Pulse Testing?

This could be how we air test buildings in the coming years, but it’s not something we can use for building regulations compliance just yet.

Air tightness testing has been a feature of Building Regulations in England and Wales since 2006 and is the reason Energist exists today.

Although targets have become stricter and the quantity of homes being tested has increased, the method used for completing the test itself hasn’t changed.

A new building is depressurised by fitting a fan to the front door, and specialist equipment is used to measure how long it takes the internal air pressure to return to normal.

During the test, a trained engineer can walk around the building and pinpoint key areas where air is escaping. The site manager can then action additional sealing works before the first occupants move in. By the time the fan is installed, the test completed, results confirmed, and the equipment removed again it’s not uncommon for a test to take an hour, if not longer.

Proposed changes to Building Regulations are suggesting that every new dwelling should be air tested. If that requirement comes into force, we’re going to need a lot more air testers, or a way of speeding up the testing process.

And this is where Pulse Testing may be able to help.

A box the size of a large speaker is used to send out a pressure shockwave from the centre of a dwelling. Information collected from this pulse is used to calculate the building’s air tightness score without the use of a door fan.

In theory this test can be completed quicker, so having a 100% testing requirement won’t be as much of an issue. It also means less equipment needs to be carried around by the air test engineer.

There are several disadvantages though… Pulse Testing isn’t currently recognised by building regulations so any tests completed using this method will not satisfy Building Control. Pulse Testing also hasn’t yet been shown to be reliable when measuring very airtight dwellings.

Another issue is that it doesn’t allow an air test engineer to walk around the building mid-test to diagnose particular problem points in a building.

If Pulse Testing is approved as part of next year’s changes to building regulations, it will bring the advantage of speed for testing more plots. The conventional door-fan approach will still have its place for pinpointing specific air leakage areas in a building, and for providing accurate results on the most air tight buildings.

For now, door fan air testing continues as the only method for meeting building regulations. If you need air leakage tests on your current building sites, contact us for information.