The Town and Country Planning (General Permitted Development) (England) Order 2015

Class N – installation etc of flue for biomass heating system on non-domestic premises

Permitted development

N.  The installation, alteration or replacement of a flue, forming part of a microgeneration biomass heating system, on a building other than—

(a) a dwellinghouse or a block of flats; or

(b) a building situated within the curtilage of a dwellinghouse or a block of flats.

Development not permitted

N.1  Development is not permitted by Class N if—

(a) the capacity of the system that the flue would serve exceeds 45 kilowatts thermal;

(b) the height of the flue would exceed either—

(i) the highest part of the roof by 1 metre or more, or

(ii) the height of an existing flue which is being replaced,

whichever is the highest;

(c) the installation of the flue would result in the installation on the same building of more than 1 flue forming part of either a biomass heating system or a combined heat and power system;

(d) the flue would be installed on a listed building, within the curtilage of a listed building or on a site designated as a scheduled monument; or

(e) in the case of a building on article 2(3) land, the flue would be installed on a wall or roof slope which fronts a highway.