Do you need planning permission for air conditioning?

The UK rules in plain English — and what they mean for Surrey’s conservation areas, AONB and listed homes.

Planning permission for air conditioning

Often you won’t need it. Since May 2025 an air conditioner (an air-to-air heat pump) can usually be fitted to a house under permitted development if it meets the MCS 020 noise standard — roughly ≤42 dB(A) at the neighbour’s window — and is sited sensibly. Conservation areas, the Surrey Hills AONB, Article 4 areas, listed buildings and flats are the main exceptions.

The general rule (permitted development)

For most houses, installing the outdoor condenser is permitted development — no planning application — provided it meets conditions set out under the updated 2025 rules and the MCS 020 noise standard. In practice that means a correctly sized, modern inverter unit, sited so it isn’t intrusive and stays within the noise limit at neighbouring windows. The old fixed “1 metre from the boundary” rule was relaxed in 2025, and houses can use a larger unit volume than before.

When you do need permission

Permitted-development rights are restricted — so consent is usually required — in these situations, all of which are common across Surrey:

Situation	Planning position	Notes
Typical house, rear/side wall	Usually permitted development	If MCS 020 noise + siting rules are met
Wall fronting a highway	Often needs permission	Especially in a conservation area
Conservation area (street-facing)	Prior approval usually needed	Rear/screened siting preferred
Surrey Hills AONB	Tighter PD rights	Discreet siting; may need approval
Article 4 area	Permission usually required	PD rights removed by the direction
Listed building	Listed building consent needed	For external (and often internal) works
Flat / maisonette	Tighter volume limits	Balcony siting; managing-agent consent too

General guidance only — always check your specific address. Rules change and individual councils interpret them differently.

In heritage-rich Surrey, getting the siting and the paperwork right is half the job — so we handle the council side for you.

How we work

Why Surrey is different

Surrey has an unusually high concentration of conservation areas, a large slice of the Surrey Hills National Landscape (AONB), and several Article 4 directions — including Guildford’s Charlotteville and parts of Mole Valley (Dorking, Leatherhead, Brockham) — that strip back permitted-development rights. Farnham’s Georgian core is an Outstanding Conservation Area with hundreds of listed buildings. The practical upshot: the rules genuinely differ street by street, which is why we assess your exact address at the free survey.

Planning by borough

Waverley Local planning rules Elmbridge Local planning rules Woking Borough Local planning rules Mole Valley Local planning rules Reigate & Banstead Local planning rules

Local planning guidance

Guildford (Charlotteville Article 4) Conservation siting Farnham (Outstanding CA) Listed-building specialists Dorking & Leatherhead (Article 4) Mole Valley All Surrey areas Town-by-town

Frequently asked questions

Do I need planning permission for air conditioning in the UK?

Often not. Since May 2025, an air-to-air heat pump (which is what an air conditioner is) can usually be installed under permitted development on a house if it meets the MCS 020 standard — broadly, no more than 42 dB(A) at the nearest neighbour’s window and sensible siting. Conservation areas, AONBs, Article 4 areas, listed buildings and flats are the main exceptions where consent is needed.

What is the MCS 020 noise rule?

MCS 020 is the standard that governs the noise of an outdoor unit for permitted development. In practice the unit must not exceed about 42 dB(A) measured at the nearest neighbour’s window. A correctly sized, modern inverter condenser sited sensibly almost always meets it.

Do I need permission in a conservation area?

Usually for any unit on an elevation fronting a highway, and often more widely. We site condensers discreetly — typically to the rear or a courtyard — and obtain conservation-area prior approval where it is required.

What about a listed building?

Listed buildings need listed-building consent for external changes (and often for internal pipe routing too). We design discreet, reversible installations — sometimes ducted to hide indoor units — and manage the consent process.

Can you handle the planning application for me?

Yes. Assessing the planning position and, where needed, preparing and submitting the application is part of the service — it’s exactly the kind of work we do across heritage-rich Surrey.

Ready for a cooler home or office?

Book a free, no-obligation survey and fixed quote with Guildford’s air conditioning specialists.

Get a free quote Call 07455 742677