Do You Need Planning Permission for Air Conditioning in the UK?

Last Updated on August 28, 2026

You want a cool house this summer without a letter from the council telling you to take the unit off the wall. The rules on planning permission for air conditioning changed significantly in May 2025, and the answer now depends less on the size of the unit and more on whether the system heats as well as cools.

This guide covers the current position in England, including permitted development rights, flats and leaseholds, conservation areas, listed buildings, noise, and a practical checklist to run through before you order anything.

The short answer

A fixed air conditioning system with an outdoor condenser can be installed without a planning application in many English homes, but only if the unit provides heating as well as cooling.

The Planning Portal makes an important distinction: permitted development rights apply where the system provides heating, including systems that both heat and cool. A cooling-only system does not qualify under those rights and requires a planning application.

That catches people out because most modern wall-mounted split systems are technically reversible air-to-air heat pumps. Specify a heat-and-cool model and the planning position can therefore be very different from a cooling-only unit.

Our guide to air source heat pumps vs air conditioners explains how the technologies overlap.

Why heat-and-cool systems can qualify for permitted development

Permitted development for these systems comes from Class G of Part 14, Schedule 2 of the General Permitted Development Order 2015, covering air source heat pumps on domestic premises.

A cooling-only air conditioner does not qualify as an air source heat pump under these rules. The legislation specifies that qualifying equipment must not be used solely for cooling.

Changes that took effect on 29 May 2025 relaxed the rules considerably for systems that do qualify.

The maximum unit volume on a house increased from 0.6 to 1.5 cubic metres, detached homes can have up to two qualifying units, and the previous requirement to keep the equipment at least one metre from the property boundary was removed.

Class G limit in England from 29 May 2025	Rule
Maximum unit volume on a house	1.5 cubic metres
Maximum unit volume on a block of flats	0.6 cubic metres
Units on a detached house	Up to 2
Units on semis, terraces and blocks of flats	1
Minimum distance from boundary	No specific minimum
Cooling	Qualifies only where the unit also heats
Pitched roof installation	Not permitted
Flat roof installation	Allowed subject to conditions, including positioning from the external edge
Listed buildings and scheduled monuments	Class G does not apply

Even where Class G applies, conditions remain. The equipment should be positioned to minimise its effect on the external appearance of the building and the amenity of the surrounding area, and it should be removed when it is no longer required.

We’ve covered the wider rules in our guide to planning permission for an air source heat pump.

What about the 0% VAT treatment?

There is a financial reason to pay attention to the distinction between a cooling-only unit and a reversible air-to-air heat pump too.

Qualifying permanently installed air-source heat-pump systems can fall within the government’s VAT relief for energy-saving materials when supplied and installed in eligible residential properties.

The current zero rate runs until 31 March 2027 under the applicable relief.

A portable air conditioner or equipment bought without a qualifying installation is treated differently, so ask your installer to confirm the VAT treatment applying to the exact system and quote.

Flats and leasehold properties

Planning permission is only one hurdle if you live in a flat.

Class G can apply to a qualifying unit on a block of flats, with a maximum unit volume of 0.6 cubic metres under the rules covered here.

But the lease can be the bigger issue.

Fixing a condenser to an external wall, drilling through the building or altering common parts will commonly require written consent from the freeholder or managing agent. Planning permission or permitted development rights do not override those private contractual restrictions.

If you own a leasehold flat, speak to the freeholder or managing agent before ordering the equipment.

A portable unit avoids the need for a permanent outdoor condenser, although the trade-off is generally higher noise and electricity consumption. Our air conditioning running costs UK guide compares fixed and portable systems.

Conservation areas and listed buildings

Conservation areas

Protected areas require more care.

The Class G rules restrict where equipment can be positioned in conservation areas and World Heritage Sites, particularly where it would be visible on elevations facing a highway.

A rear elevation or discreet side position may therefore be easier to accommodate than a condenser mounted prominently on the front of the property.

Do not assume that simply owning a reversible heat-and-cool system guarantees permitted development rights in a conservation area. Check the property’s specific restrictions and speak to the local planning authority where necessary.

Listed buildings

Listed buildings are much more straightforward: Class G permitted development rights do not apply.

You may therefore need planning permission for the external equipment, and listed building consent can also be required for work affecting the building’s special architectural or historic character.

That can include apparently minor work such as drilling refrigerant pipework through historic masonry.

Possible alternatives include locating equipment discreetly in a rear lightwell or outbuilding, using systems that allow external equipment to be concealed where appropriate, or falling back to portable cooling where permanent alterations cannot be approved.

Early advice from the council’s conservation team is sensible before equipment is purchased.

What about noise?

The planning changes introduced in May 2025 altered the way noise requirements interact with permitted development in England.

Before the changes, Class G permitted development was tied to the MCS Planning Standards and the MCS 020 noise calculation, including its assessment methodology.

The amended rules removed that specific MCS requirement from the Class G planning conditions in England.

That does not mean condenser noise no longer matters.

Local authorities can still consider noise where a full planning application is required, and poor positioning can also create complaints regardless of whether the installation originally fell under permitted development.

A condenser mounted directly beneath a neighbour’s bedroom window is an obvious example of a location worth avoiding.

Ask the installer to consider neighbouring windows, boundaries, reflective walls and the manufacturer’s outdoor-unit noise figures before deciding where the condenser will go.

What to check before ordering air conditioning

Confirm that the system heats as well as cools

A cooling-only system does not benefit from the Class G permitted development rights described here. Most modern domestic splits are reversible, but confirm this rather than assuming.

Check the unit size and number

For qualifying installations in England, the amended Class G rules allow equipment up to 1.5 cubic metres on a house and up to two units on a detached house, subject to the other conditions.

Check your lease

If you live in a flat or leasehold property, get any required freeholder or managing-agent consent before installation.

Check whether the property is protected

Listed buildings, conservation areas, World Heritage Sites and other protected locations need additional attention.

Think about condenser noise before choosing the position

Moving the outdoor unit away from neighbouring windows at the design stage is far easier than relocating it after a complaint.

Use an appropriately qualified installer

Anyone carrying out work involving fluorinated refrigerants must hold the relevant F-gas qualifications.

The installation may also need to comply with applicable building regulations and electrical requirements.

Consider a lawful development certificate if the position is unclear

Where you want formal confirmation that a proposed installation is lawful under permitted development, a lawful development certificate can provide evidence of that position.

This can be particularly useful where the property or proposed installation is not straightforward.

Does the type of air conditioning system affect planning?

Yes, because the number and location of outdoor units can change.

A single split normally has one outdoor condenser serving one indoor unit. Install three independent single splits and you could end up with three external units.

A multi-split can serve several rooms from one condenser, potentially making the exterior of the property much easier to manage.

That can be especially useful where the number of permitted units, appearance or available outside space is a concern.

Our split vs multi-split air conditioning guide explains the trade-offs.

If you’re still choosing the equipment itself, see our guide to the best air conditioning units in the UK.

Can solar power your air conditioning?

Planning permission for the air conditioner and the way you power it are separate issues, but solar can pair particularly well with fixed cooling.

The hottest and brightest parts of the day often coincide, meaning solar panels can directly offset some of the electricity an air conditioner would otherwise draw from the grid.

We’ve covered whether a solar battery can run an air conditioner and how many solar panels you need to run air conditioning separately.

FAQs

Do portable air conditioners need planning permission?

Generally, no. A normal portable air conditioner does not involve permanently installing an outdoor condenser or altering the building in the same way as a fixed split system.

The downside is that portable units are generally noisier and less efficient than a properly installed split system.

Does 0% VAT apply to air conditioning?

Qualifying permanently fixed air-to-air heat pumps can fall within the VAT relief for energy-saving materials when supplied and installed in eligible residential circumstances.

The current zero rate runs until 31 March 2027.

Cooling-only equipment, portable units and equipment-only purchases can be treated differently, so check the VAT treatment stated on your quotation.

Do the same planning rules apply in Scotland, Wales and Northern Ireland?

No. The Class G rules and May 2025 changes covered in this article apply to England.

Scotland, Wales and Northern Ireland have their own planning and permitted development regimes. Check the current position with the relevant local authority before installing a fixed external unit.

What happens if I install air conditioning without the permission I need?

The local planning authority can take enforcement action against unauthorised development and may require the equipment to be removed.

In some circumstances you may be able to apply retrospectively, but that does not guarantee approval.

Unauthorised work to a listed building can be much more serious, so get the necessary advice and consents before carrying out alterations.

Do I need planning permission for a multi-split air conditioner?

The same basic distinction applies: the equipment needs to satisfy the relevant permitted development requirements, including providing heating rather than being cooling-only.

A multi-split can actually make the planning position simpler in some homes because several indoor units can share one outdoor condenser.

Our Verdict

For most homeowners in England, the simplest route is to choose a reversible fixed system that provides heating as well as cooling.

Most modern domestic split systems already work this way, and qualifying air-to-air heat pumps can benefit from the permitted development rules that were relaxed in May 2025.

Cooling-only equipment is different and does not benefit from those Class G rights.

Flats, leasehold properties, conservation areas and listed buildings need more care. Check the lease, property designation, proposed condenser position and any required permissions before buying the equipment.

If there is any uncertainty, confirm the position with your local planning authority before installation. Sorting that out before a condenser goes on the wall is considerably easier than dealing with an enforcement issue afterwards.

Sources

• UK Legislation – Class G: Installation or Alteration of Air Source Heat Pumps on Domestic Premises (accessed 27 August 2026)
• Planning Portal – Do I Need Planning Permission to Add Air Conditioning to My Home? (accessed 27 August 2026)
• Planning Geek – Class G Air Source Heat Pumps (accessed 27 August 2026)
• GOV.UK – Qualifications Required to Work on Equipment Containing F-Gas (accessed 27 August 2026)
• GOV.UK – VAT on Energy-Saving Materials and Heating Equipment (accessed 27 August 2026)
• Planning Portal – Listed Building Consent (accessed 27 August 2026)