Meeting the Conditions for Permitted Development

To ensure your non-domestic flue project qualifies for permitted development and avoids a full planning application, you must satisfy several specific criteria. If your proposed installation fails to meet any of these points, you will certainly need to apply for planning permission.

• Your system's thermal capacity – meaning its heat output – must not exceed 45 kilowatts.

• Remember, permitted development rights apply strictly to the very first flue you install as part of either a biomass heating system or a combined heat and power (CHP) system. For any additional flues you wish to install after this initial one, you will be required to submit a planning application.

• When positioning your flue, its height must not extend more than one metre above the tallest part of your roof. Should you be replacing an existing flue, the height limit for the new installation is different: it cannot be taller than the original flue, nor can it exceed one metre above the highest point of the roof. You must comply with whichever of these two measurements allows for the greater overall height.

• You are prohibited from using permitted development rights for flue installations on, or within the surrounding grounds of, any building that holds listed status. This same restriction also applies to sites officially designated as scheduled monuments.