The two main ways to achieve airtightness in the building envelope are internally or externally, or in other terms, ‘inside of the services zone’ or ‘outside of the services zone’. The use of traditional internal air barriers can be more complex and costly to install, due to the need to accommodate building services such as electrical, lighting, heating and drainage systems.
An internal air barrier is only as good as it’s installation. If all the service penetrations are not adequately sealed, performance will be compromised.
