Do I Need Planning Permission for Air Conditioning?

Usually not — but "usually" is doing some work in that sentence, and the exceptions matter.

This article is general guidance, not a planning decision. Your installer should confirm the position for your specific property, and your local planning authority is the final word.

Permitted development

Most domestic air source heat pump installations in England fall under permitted development rights, meaning you don't need to apply for planning permission. Air-to-air systems — the wall-mounted units this site is about — were brought within those rights.

But permitted development comes with conditions attached, and if you fail any of them, you need permission.

The conditions that catch people out

It can't be cooling only. The rules cover heat pumps. A unit that only cools, with no heating function, doesn't qualify. In practice this rarely bites, because almost everything sold now is reverse-cycle — but it's a reason not to buy the cheapest cooling-only box you can find online.

Certification requirements. The installation must meet the relevant standard, which sets out siting and noise requirements. Your installer should be working to this as a matter of course.

Noise and siting. There are rules about where the outdoor unit can go and how loud it can be at your neighbour's property. This is the condition most likely to affect where the unit ends up on your wall.

Number of units. The noise assessment methodology covers a limited number of outdoor units. This is a good practical reason to run several rooms from one properly sized outdoor unit rather than bolting on extra ones over time.

When you definitely need permission

• Listed buildings — you'll need listed building consent, and it's a real process
• Conservation areas — additional restrictions typically apply, especially on anything visible from the road
• Flats and maisonettes — permitted development rights for houses often don't extend to flats
• Rented property — not planning, but you'll need your landlord's written consent

What to do about it

If you're in a conservation area or a listed building, say so at the very first conversation. It changes what's possible and it's much better dealt with before a survey than after a quote.

For everyone else, the practical answer is that a competent installer will site the outdoor unit to stay within permitted development, and will tell you if your property is one of the exceptions.

Ask them directly. "Will this be within permitted development, and can you confirm that in writing?" is a fair question and any decent firm will answer it without hesitation.