AIR TIGHTNESS TESTING

Now more than ever before, there are any number of things we can do to ensure the energy efficiency of new dwellings and commercial buildings. Much like ensuring the security of a home, there now exists a wide range of additions we can make in order to guarantee that new builds are up to the task of safeguarding the country’s carbon footprint, and ensuring a more sustainable way of life now, and in the future.

These new measures, however, mean little if the build itself is unable to provide the groundwork for energy efficiency, and it is for this reason that air tightness testing proves so essential to modern developments. If air is able to leak from the building, then this translates to a considerable loss – both in terms of efficiency, and money.

Read more below to find out why checking for air tightness represents such a crucial step in the road to project completion, and how to prepare for your test.

What is Air Leakage?

In any building, there will be controlled points through which air is able to escape; no domestic or commercial property can be wholly airtight. Window trickle vents, for instance, represent points of controlled (or passive) ventilation, and a necessary addition to any new build.

Air leakage refers to points of uncontrolled ventilation, which can occur unintentionally during construction and represent weak points in the structure through which heat will be lost. Exfiltration points are particularly common in the bathrooms and kitchen, where pipes are entering into the property.

These areas will be difficult – or, more commonly, impossible – to identify by eye, which is why a standardised testing method is so vital to all new builds.

What is Air Tightness Testing?

Also known as air pressure testing, this methodology calculates the air tightness of a building, known as its ‘air permeability’ or ‘leakage’ rate. Air leakage is air that escapes the building via uncontrolled means. Leakage can occur through gaps, holes or cracks in the fabric of the building, and these are impossible to identify without proper testing.

Excessive air leakage can affect the building’s energy efficiency, making the building less energy efficient and more expensive to keep warm in the colder months – thus leading to a considerable increase in carbon dioxide emissions.

Do I Need a Test for a New Non-Domestic Property?

According to Part L1A and L2A, non-domestic buildings comprising 500 square metres or more will need to undergo air leakage testing, which will represent an essential component in your SBEM (Simplified Building Energy Model).

Larger buildings typically require more fans in order to attain the right level of pressurisation, but this will be handled by your technician on the day.

How is the Test Performed?

Obviously, any leakage testing cannot be carried out until the basic structure of the building has been completed. At this stage, any areas of the building through which ventilation is necessary and controlled – such as those window trickle vents, or the chimney – will be sealed in order to identify points through which air is leaking.

The building is then pressurised via a fan (or multiple fans, for larger builds) which will be temporarily attached to an outer doorway, to a Pascal Unit (Pa) of 50 to 100 in order to create a pressure differential between the inside and the outside. Any leakage can then be measured, and the assessor can work to identify areas that need to be addressed before the property is able to pass the test – although, provided work has been completed prior to the test taking place, the majority do pass first time.

For the test to be completed, any internal work should (ideally) cease, and workers should vacate the building for the test’s duration – which is typically under an hour, if the building passes first time.

How Do You Prepare for an Air Tightness Test?

The most important factor to consider before arranging your test is the completion of all structural work to the property. While it is tempting to complete the test and get your result as soon as possible, there is very little value in arranging an air permeability test before the work that will ensure the building’s air tightness has been completed – this is the most common cause of a building not passing first time.

You should also ensure that you are equipped with the necessary SAP calculations, in order to streamline the process on the day of the test and make certain that you are cognisant of the limit for your project.

The air tightness test represents only a minor disruption to work-as-usual, and will offer the assurance and peace of mind you need to complete your build or builds.

Who Performs an Air Tightness Test?

Our team of technicians are fully qualified to perform air permeability testing on new dwellings, extensions, and non-domestic buildings, and to provide you with the assistance you need to ensure compliance with building regulations and your SAP calculations.

If you are reaching the end of a project, then get in touch with our team today. They will be able to offer all the advice you need for preparing for, and passing, your air permeability test – and ensuring that work can continue on schedule, and to the highest possible standard.