Do you need planning permission for air conditioning in London?

The short version

Air conditioning installations can fall under permitted development, meaning no planning application is required. But the right is written specifically for air source heat pumps, and it comes with conditions that catch out a large share of London properties.

Why cooling-only units are excluded

This is the rule almost nobody mentions. The permitted development right exists to encourage air source heat pumps as an energy-efficiency measure. A unit that only cools does not meet that definition, so it sits outside the right entirely and needs an application regardless of where it goes.

In practice most modern split systems sold in the UK are reversible — they heat as well as cool — and therefore qualify. But it is worth confirming the specific model rather than assuming, particularly with cheaper imported units.

The conditions, in full

Where the right does apply, the installation must satisfy all of the following:

• The external unit must be no more than 0.6 cubic metres in volume
• It must sit at least one metre from the property boundary
• It must not be installed on a wall or roof of the principal elevation fronting a highway
• It must not be sited on a pitched roof, or within 1 metre of the edge of a flat roof
• It must meet the applicable noise conditions at the neighbouring assessment position
• It must be removed when no longer needed
• The property must not be a flat, maisonette, or listed building

Conservation areas: the North London problem

This is where most of my patch sits. Camden operates around 40 conservation areas covering roughly half the borough, and Haringey has 29, including Highgate Village, Muswell Hill, Crouch End and Fortis Green.

Inside a conservation area, permitted development is restricted rather than removed. The practical effect is that a unit visible from a highway will need permission, and an Article 4 direction — which councils can apply to specific areas — may remove the right altogether.

What this means on the ground: rear elevations, lightwells, side returns and screened positions are the realistic candidates. Front elevations are almost never acceptable. The design conversation and the planning conversation are the same conversation.

Flats and leasehold: two separate hurdles

If you live in a flat, you face two independent requirements and both must be satisfied:

1. Planning permission from the council, because flats have no permitted development rights for heat pumps.
2. Freeholder or managing agent consent, because your lease almost certainly restricts alterations to the exterior and the structure.

These run in parallel, not in sequence, and the consent side is usually the slower of the two. A well-prepared pack — condenser position marked on an elevation, unit dimensions and weight, sound data, fixing method, installer F-Gas registration and insurance — gets approved far more often than a vague request.

Listed buildings

A listed building needs listed building consent in addition to planning permission, and the assessment considers internal fabric as well as external appearance. Pipe routes that penetrate original walls, or fixings into historic brickwork, will be scrutinised.

It is often still achievable. It takes longer, costs more, and requires an installer who will design around the constraint rather than through it.

What I do about it

At survey I check your property's conservation status, whether it is listed, whether it is a flat, and whether the system specified is reversible. Then I tell you which of the four situations above you are in, before you have spent anything.

Where an application is needed, I will set out what is involved and can supply the technical information the application requires. What I will not do is install something that should have had permission and leave you to deal with the consequences.

This guide is general information, accurate to the best of my knowledge in August 2026. Planning rules change and interpretation varies between boroughs. Always confirm your specific position with your local planning authority before proceeding — Camden, Barnet, Brent, Haringey and Harrow all run free pre-application enquiry services.