Planning permission for air conditioning in England

Most homes in England can now add an air conditioning system without a planning application, as long as the system heats as well as cools and stays inside some clear limits. This is general guidance, not legal advice: your council has the final word.

What changed in May 2025

Permitted development rights let you carry out some work without applying for planning permission. In England the rules for heat pumps on homes changed on 29 May 2025. An air-to-air system, which is what most people mean by air conditioning, can now come under those rules, on condition that it is not used only for cooling.

The main limits

• One outdoor unit on a house that is not detached, or on a block of flats. Up to two on a detached house.
• The outdoor unit, with any housing, no bigger than 1.5 cubic metres on a house, or 0.6 cubic metres on a block of flats.
• Not on a pitched roof, and not within 1 metre of the edge of a flat roof.
• Not on a wall that faces a road, above the ground floor.
• It must meet the noise and siting standards the rules refer to, and sit where it has the least effect on how the building looks and on the neighbours.
• It must be taken away when it is no longer needed.

When you will need to apply

A unit that will only ever cool is not covered, so it needs the council’s view first. Listed buildings are outside these rights too, and in a conservation area a unit cannot go on a wall or roof that faces a road, or nearer to a road than the house itself.

In a flat, read your lease as well. Many leases need the freeholder’s written consent for anything fixed to an outside wall, whatever the planning position.

What we check at the survey

Whether the system you want heats as well as cools, how big its outdoor unit is, where it can sit away from roads and bedroom windows, and whether the house is listed or in a conservation area. If anything points to an application, we say so before anything is booked.

Source: The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 14, Class G, as amended from 29 May 2025 (legislation.gov.uk, read 4 November 2026).