Do I need planning permission for the indoor unit?

No. Planning control is about the outside of a building, so an indoor unit on an inside wall needs no permission. The outdoor unit and any pipework or trunking on an outside wall are what the rules look at. A listed building is the exception, because listing covers the interior too, so even internal pipe runs can need listed building consent.

Is the 1 metre boundary rule for heat pumps still in force?

No. Paragraph G.2(e), which kept every part of the unit at least 1 metre from the property boundary, was deleted on 29 May 2025. A unit can now sit right next to a shared fence if it still passes the 37 dB(A) noise calculation at the neighbour's window. In Leeds terraces the noise sum is usually the real limit.

Can I put an air conditioning unit on the front of my house?

Outside a conservation area, yes, on a ground-floor wall that fronts the road, but not higher up. Inside one of Leeds' 80 conservation areas, no wall or roof facing a highway is allowed under permitted development, so a front-wall unit needs planning permission. The usual answer is a rear wall or back garden.

How long does a householder planning application take in Leeds?

Under article 34 of the Development Management Procedure Order 2015, the council should decide a householder application within 8 weeks of it being made valid, unless you agree a longer period in writing. Before you apply, the council's pre-application enquiry service can flag problems such as a conservation area objection. If you want the unit running for summer, submit in winter or early spring, then book the install once you have the decision notice.

Who is responsible for checking that the installation is permitted development?

The property owner carries the planning risk. A good installer will run the MCS 020 a) calculation, give you a copy, and flag conservation area, listed building and lease issues at survey, but any enforcement action from the council would be aimed at the owner. A lawful development certificate confirms in writing that the proposed work is permitted, which helps when you sell.

Air Conditioning Planning Permission: Leeds & UK Rules 2026

Do you need planning permission for air conditioning in Leeds?

Usually not, if you live in a house, the system heats as well as cools, and the outdoor unit passes the limits in Class G of the national permitted development rules. Those rules were relaxed on 29 May 2025, so a typical wall-mounted split system on a Leeds semi or detached house no longer needs an application.

Permission is still needed for a cooling-only unit, any listed building, a street-facing wall in one of Leeds' 80 conservation areas, and a block of flats that already has an outdoor unit. Planning rules look at the outdoor unit, not the indoor one.

Which law covers a home air conditioning unit?

In England the rules sit in Class G of Part 14, Schedule 2 of the Town and Country Planning (General Permitted Development) (England) Order 2015, usually shortened to the GPDO. Class G covers the installation, alteration or replacement of an air source heat pump on a house or a block of flats, or within its garden. A split air conditioner that heats and cools is an air-to-air heat pump, so Class G is the right that applies to it.

The rules were rewritten by the GPDO Amendment Order 2025 (S.I. 2025/560), which came into force on 29 May 2025. A transitional saving for jobs relying on the old "equivalent standards" wording ended on 28 May 2026, so the MCS 020 a) noise calculation is now the only route. The Planning Portal heat pump guidance says the same.

Wales, Scotland and Northern Ireland have their own rules. Everywhere we cover is in England.

What changed in May 2025?

If a page tells you a heat pump must sit a metre from the boundary, it predates the amendment. Here is the old rule set against the current one:

Boundary distance: before 29 May 2025 no part of the unit could be within 1 metre of the boundary. That rule (paragraph G.2(e)) has been deleted.
Use: the old condition was that the heat pump was "used solely for heating purposes", which ruled out air conditioning. The new condition is that it is "not solely used for the purpose of cooling".
Number of units: one per property before. Now one on a semi, terrace or block of flats and two on a detached house.
Size: the outdoor unit used to be capped at 0.6 cubic metres. A house can now have up to 1.5 cubic metres. Blocks of flats stay at 0.6.
Noise standard: "MCS Planning Standards or equivalent standards" became MCS standards only.
Flat roofs: unchanged. A unit still has to be at least 1 metre from the outer edge.

The permitted development limits for a house

Every one of these has to be met. Fail one and you need planning permission for that position, though a different position may pass.

The outdoor unit, including any housing, is 1.5 cubic metres or less. A unit of 0.8m by 0.55m by 0.3m is 0.132 cubic metres.
No more than one unit on a semi-detached or terraced house, or two on a detached house, counting any heat pump already there.
No wind turbine on the house or in the garden.
Not on a pitched roof, and not within 1 metre of the edge of a flat roof.
Outside a conservation area, not on a wall that fronts a highway above ground floor level.
Inside a conservation area, not on any wall or roof that fronts a highway, and not closer to a bounding highway than the house itself.
Passes the MCS 020 a) calculation of 37 dB(A) at every neighbouring habitable room window.
Sited, so far as practicable, to limit its effect on the look of the building and the amenity of the area, and removed when no longer needed.

Does a cooling-only air conditioner need planning permission?

Yes, in almost every case. Condition G.3(aa) says the heat pump must not be used solely for cooling, so a system fitted and run only for summer cooling sits outside Class G and needs a planning application. Bristol City Council's householder guidance states that a cooling-only system will usually need planning permission.

This rarely blocks anyone, because nearly every split sold for UK homes is reverse cycle and can heat as well as cool. Use it for heating and you are within the condition. It is cheap heat, too. At the Ofgem price cap for October to December 2026, electricity is 26.32p per kWh, so a unit with a seasonal efficiency (SCOP) of 4.0 makes heat for 26.32 / 4 = 6.6p per kWh. Our air-to-air heat pump guide runs the full winter comparison against gas.

How the 37 dB(A) noise check works

MCS 020 a) is a desk calculation. It starts from the unit's sound power on the data sheet, adjusts for hard surfaces within a metre of it, then subtracts for distance and any solid barrier. The formula is Lp = Lw + 10 x log(Q / (4 x pi x r squared)) minus the barrier figure. The answer must be 37.0 dB(A) or lower at every assessment position, which is a point 1 metre outside the neighbour's window.

The directivity factor Q is the part people get wrong. A unit on wall brackets clear of the ground has one reflecting surface (Q2). On the ground against a wall it has two (Q4), and in a ground-level corner three (Q8). More than three, as in a small lightwell, cannot comply.

Worked example. A through terrace in Armley has a ground-mounted outdoor unit against the back wall (Q4), rated at a sound power of 60 dB(A). The neighbour's back bedroom window is 5 metres away. The sum is 60 + 10 x log(4 / (4 x 3.1416 x 25)) = 60 minus 18.95 = 41.0 dB(A). That is 4 dB(A) over the limit, so this position fails.

There are three ways to fix it. A solid brick wall or a fence at least 18mm thick that completely hides the window from the top of the unit counts as a Type 1 barrier with no view, worth 10 dB, giving 31.0 dB(A). Moving the unit to 9 metres gives 60 + 10 x log(4 / (4 x 3.1416 x 81)) = 35.9 dB(A), which passes with no barrier. Lifting it onto wall brackets (Q2) at the original 5 metres gives 38.0 dB(A), which still fails, so brackets alone would not be enough here. MCS installers must give you a copy of the completed table. Our guide on whether air conditioning is noisy covers sound levels indoors and out.

Two outdoor units on a detached house: the combined noise sum

Detached houses can now have two outdoor units, which suits the larger homes in Alwoodley, Roundhay and Adel where a single multi-split would need very long pipe runs. The catch is that MCS 020 a) adds the two units together at any window both can reach, and decibels do not add like ordinary numbers.

Take two units rated at 58 dB(A) each, both ground-mounted against a wall (Q4). The neighbour's nearest bedroom window is 10 metres from unit A and 12 metres from unit B. Unit A gives 58 + 10 x log(4 / (4 x 3.1416 x 100)) = 33.0 dB(A). Unit B gives 58 + 10 x log(4 / (4 x 3.1416 x 144)) = 31.4 dB(A). The combined level is 10 x log(10^3.30 + 10^3.14) = 35.3 dB(A). That passes, with 1.7 dB(A) to spare.

Now the trap. Two identical units that each give 35.0 dB(A) at the same window combine to 35.0 + 3.0 = 38.0 dB(A), which fails. Each one passes when checked alone. Ask for the combined figure at every window both units reach. Our North Leeds suburbs page covers the house types where this comes up most.

Conservation areas in Leeds: which walls are off limits?

Leeds City Council lists 80 conservation areas across the district, each with a boundary map and, for 55 of them, an appraisal. They include Headingley, Far Headingley, Chapel Allerton, Roundhay, Gledhow Valley, Meanwood, Horsforth, Morley, Otley, Wetherby and Leeds City Centre, plus villages such as Thorner and Boston Spa.

Inside a conservation area Class G stops a unit going on any wall or roof that fronts a highway, at any height. It also stops a unit being nearer to a highway that bounds the property than the nearest part of the house.

Most conservation area homes can still use the rear wall or back garden without an application. Corner plots are the awkward ones, since two sides of the house front a highway. On a stone semi in Chapel Allerton with a side road, the only compliant positions may be on the back wall well away from the side street. Our page on Headingley, Chapel Allerton and Kirkstall has more on the terraces and student lets in those streets.

Back-to-backs and corner terraces

Leeds has about 19,500 pre-1919 back-to-back houses still in use, according to the Leeds Housing Strategy. A back-to-back shares its rear wall with the house behind, so the only outside wall is usually the one facing the street. Outside a conservation area that wall can take a ground-floor unit, which is often in a small front yard. Inside a conservation area the street wall is ruled out, so you are left with a planning application or no outdoor unit at all.

Through terraces are easier because they have a back yard, though yards in Harehills, Beeston and Armley are often small enough that the noise sum to the neighbour's kitchen or bedroom window is tight. A terraced house is limited to one outdoor unit, so cooling two rooms means a multi-split with one outdoor unit feeding both. Our terraced and back-to-back guide covers pipe routes through solid walls.

Listed buildings and listed building consent

Class G does not apply at all to a listed building or anything within its curtilage, so an outdoor unit at a listed house always needs planning permission. Fixing anything to the building, including core drilling for pipes or running trunking inside, will usually need listed building consent as well. Leeds City Council says there are over 3,300 listed buildings in Leeds, and listing covers the whole building, inside and out.

Work to a listed building without consent may be a criminal offence. If you live in a converted mill or a Georgian terrace near Park Square, check Historic England's National Heritage List before any survey.

Flats and leasehold homes

Class G does cover blocks of flats, but with two tight limits. The outdoor unit can be no larger than 0.6 cubic metres, and the block can have only one air source heat pump in total. The block must consist wholly of flats, so one with shops below does not qualify. If a neighbour already has an outdoor unit on the block, yours needs a planning application.

Planning is the smaller hurdle for most leaseholders. Leases usually reserve the outside walls and roof to the freeholder, so you need written consent before drilling, and some leases ban external units. Get it before you pay a deposit. Converted warehouses in Holbeck may also be listed or in a conservation area. Our Leeds city centre flats guide covers balconies and what to ask the managing agent.

Article 4 directions and planning conditions

An Article 4 direction lets a council remove specific permitted development rights in a defined area. The direction Leeds City Council publishes on its planning pages covers houses in multiple occupation in areas including Headingley, Hyde Park and Woodhouse, Kirkstall and Chapel Allerton. It controls turning a house into a small HMO. It does not remove the heat pump right, so a landlord in those areas can still fit a compliant split system without an application.

Newer estates are a different matter. The original planning permission for a house can include a condition that removes some or all permitted development rights, and the Planning Portal warns that these can affect heat pumps. On a newer build, check the original decision notice before relying on Class G.

A five-step check for any Leeds address

Run this before you book a survey, with the council's maps open. If all five answers are clear, the job is permitted development.

Is the property a house, or a flat in a block made up only of flats? Anything else, including flats over shops, needs an application.
Is it listed? Search the National Heritage List. If yes, stop here and talk to the council.
Is it in one of the 80 conservation areas? Open the council's area map and rule out any wall or roof facing a road.
Does the original planning permission or the lease restrict external work? Read the decision notice and the lease.
Does the planned position pass MCS 020 a) at every neighbour's window, with both units counted together on a detached house?

If you do need permission

Failing a limit is not a refusal. It means a householder planning application, usually made through the Planning Portal, and the council then judges the effect on the street and on neighbours. Since 1 April 2026 the national fee for altering a single house in England has been £548, according to the government's indexed fee schedule, A lawful development certificate for a proposed job, which gives written certainty that it is permitted, costs half the equivalent fee: £548 / 2 = £274.

Include the MCS 020 a) table, the data sheet, a photo of the position and a plan showing distances to windows. For anything doubtful, Leeds City Council runs a pre-application enquiry service.

Shops, offices and other commercial premises

Class G is for homes only. Condensers on shops, restaurants and offices normally need planning permission, especially on a street frontage.

If a neighbour complains after installation

A unit that meets permitted development does not have to come out just because a neighbour objects. The council can still investigate the noise as a possible statutory nuisance under its noise complaint process, and that is judged on the noise itself. Keep the MCS 020 a) table, ask for anti-vibration mounts, and avoid pointing the fan at a bedroom window.

Our partner installers are MCS certified and apply the 0% VAT rate to domestic air-to-air heat pump installs. To have them check your address and run the noise calculation at survey, request a free quote with your postcode and the rooms you want covered.

Sources

Guidance is general and indicative. Always confirm details with a qualified F-Gas registered installer. Get a free quote.

Air conditioning planning permission in Leeds: permitted development, conservation areas and flats