Air Tightness Testing

In Scotland, air tightness testing is required for all new buildings, including residential and non-residential buildings, as well as buildings undergoing major renovation.

Building Services- Onsite Verification

Air Tightness Testing



Air Tightness

Air tightness refers to the measure of how effectively a building or structure can prevent air leakage between the interior and exterior environments. In other words, it is a measure of how well the building envelope, which includes the walls, roof, windows, doors, and other components, can prevent air from entering or escaping.

The air tightness of a building is typically measured using a blower door test, which involves using a fan to pressurize or depressurize the building and then measuring the resulting air flow through any leaks or gaps in the envelope. A lower air leakage rate means that the building is more air tight and can result in improved energy efficiency, indoor air quality, and overall comfort. However, achieving high levels of air tightness requires careful design, construction, and testing to ensure that the building is still adequately ventilated and free from issues such as condensation and mould growth.

Air Tightness Testing

In Scotland, air tightness testing is required for all new buildings, including residential and non-residential buildings, as well as buildings undergoing major renovation. The testing is required to comply with the Scottish Building Regulations, specifically Section 3 (Ventilation) and Section 6 (Energy) at the SAP/EPC stages.

The air tightness testing is carried out by our partner certified air tightness tester under the Air Tightness Testing and Measurement Association (ATTMA) guidelines.

The testing involves pressurizing the building and measuring the air leakage using specialized equipment. The results are reported as an air permeability rate, measured in cubic meters per hour per square meter of building envelope area. The maximum permitted air permeability rate for new buildings in Scotland is 7m3/hm2.hr @50Pa.

It is important to note that the air tightness testing requirements may vary depending on the specific ventilation design of the building, so it is always recommended to consult with a qualified professional to ensure compliance with the relevant regulations.

How many tests to do?

In many cases, a single air tightness test performed at the end of construction or during commissioning can be sufficient to verify the overall air tightness of the building envelope. This test can help identify any leaks or areas of concern that may need to be addressed before the building is occupied.

However, in some cases, additional air tightness testing may be necessary, such as if a particular low value is needed or in a retrofit. In these cases, it may be useful to perform additional air tightness tests to ensure that the building will meet the desired air leakage targets and to identify any new leaks that may have been introduced.

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