Description

An airtight building is one which does not loose either heated or cooled air to the outside in an uncontrolled manner. In practice, no buildings are entirely airtight and it would not normally be desirable for this to be the case. However, high performance levels are desirable for various reasons.

Air tightness testing is a method of measuring the extent to which heated or cooled air is lost through leaks in the building. Air tightness testing can also be referred to as air leakage or air pressure testing.

This sheet provides an explanation of Part L requirements for air tightness testing of buildings, including:
What is air tightness testing?
Why is air tightness testing important?
The air tightness testing process.
Part L air tightness regulatory requirements.