Do I need planning permission for air conditioning in England?

When you need permission

An air-to-air heat pump that provides heating as well as cooling can be permitted development in England if every Class G limit and condition is met. The installation must comply with MCS 020a; an outdoor unit must be no more than 1.5 m³ for a house (0.6 m³ for a block of flats); and only the first unit is permitted on a non-detached house or block, or the first two on a detached house. A unit above ground-floor level on a street-facing wall still needs permission.

A cooling-only unit does not qualify for this heat-pump permitted-development route. Check with the local planning authority whether another permission route applies. A heat pump that heats as well as cools may qualify if it meets the conditions.

Conservation areas: the unit must not be on a wall or roof facing a highway, or nearer to a highway than the building. Listed buildings and scheduled monuments do not have these permitted-development rights. A block of flats can use the Class G route if every condition is met; leaseholders should also check their lease and obtain any required freeholder consent.

Flats and leaseholds

Class G can apply to a block of flats if every national limit and condition is met, but each proposal needs a site-specific planning check. Leaseholders should also check their lease and obtain any required freeholder consent.

Managing agents will usually ask for the installer's drawings, the noise assessment, and evidence of insurance. Certified installers keep these to hand.

Conservation areas and listed buildings

In a conservation area, anything visible from the street — including a discreet condenser on the front — generally needs planning consent. On a listed building, listed building consent is also required, whichever wall the unit sits on.

Rear light-wells, side returns and roof spaces hidden from view are the usual solutions.

What installers handle for you

An MCS-certified installer will do the noise assessment, propose a location that meets the rules, draft the planning submission if one is needed, and apply for the £2,500 Boiler Upgrade Scheme grant on your behalf. You sign, they file.