Additional flue terminal separation rules
300 mm
Beyond standard table distances, all flue terminals must maintain a minimum 300mm clearance from any combustible material, such as window frames
Beyond standard table distances, all flue terminals must maintain a minimum 300mm clearance from any combustible material, such as window frames. If a heat shield is installed, it should be at least 750mm wide to protect combustible materials. Terminals for vaporising burners require a minimum 2.3m horizontal separation from the roof, and vertical balanced flue outlets must follow manufacturer instructions.
Basis in regulation
How to check it on site
Confirm all terminals are at least 300mm from combustible window frames, and verify heat shield dimensions if present.
Common failure
Terminal placement too close to combustible window or door frames, ignoring the absolute minimum clearance requirement.
Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.