Flues for biomass and combined heat and power systems (non-domestic)

Planning permission

In many cases installing a flue on non-domestic land as part of a biomass heating system, or a combined heat and power system, is likely to be considered permitted development with no need to apply to the council for planning permission.

There are, however, important limits which must be met to benefit from the permitted development rights:

  • The capacity of the system must not exceed 45 kilowatts thermal
  • Only the first installation of a flue as part of either a biomass heating system or a combined heat and power system will be permitted development. Further installations will require planning permission from the local authority
  • The flue must not be more than one metre higher than the highest part of the roof, or the height of an existing flue which is being replaced, whichever is the highest
  • Permitted development rights do not apply to installing flues on listed buildings, within the grounds of a listed building, or on a site designated as a scheduled monument.
Non-domestic land for the purposes of these permitted development rights is broad and can include businesses and community buildings.

You may wish to discuss with the local planning authority for your area whether all of the limits will be met.

Permitted development rights are also available for domestic properties:


If the building is on designated land* the flue should not be installed on a wall or roof slope which fronts a highway.

* Designated land includes national parks and the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites.

If you are a leaseholder you may need to get permission from your landlord, freeholder or management company.