Most homeowners in Worcestershire can install a reversible air conditioning system without applying for planning permission. The rules changed on 29 May 2025, and they now clearly include air-to-air systems. There are conditions, though, and some homes, including listed buildings, flats and houses in conservation areas, have extra restrictions. This guide sets out the current position in England. It isn't legal advice, so if you're unsure, check with your council before you commit.
What changed in May 2025
Outdoor heat pump units on houses have long been allowed under permitted development (Class G of Part 14 of the General Permitted Development Order). An amendment that came into force on 29 May 2025 made several changes:
- It brought air-to-air heat pumps, the type used in home air conditioning, within Class G.
- It removed the old rule that the outdoor unit had to be at least 1 metre from your boundary.
- It increased the maximum size of the outdoor unit on a house to 1.5 cubic metres.
- It allows two outdoor units on a detached house. Semi-detached and terraced houses are still limited to one.
The conditions that matter for air conditioning
- It must not be used only for cooling. A reversible system that heats as well as cools qualifies. A cooling-only system doesn't. Most systems sold for homes are reversible.
- Noise. The installation must meet the MCS 020(a) planning standard. In practice, the sound from the outdoor unit must not exceed 37 dB(A) at your neighbours' nearest habitable room window, measured 1 metre outside it. Choosing a quiet unit and the right position is how installers meet this.
- Roofs. The unit can't go on a pitched roof. On a flat roof it must be more than 1 metre from the edge.
- Walls facing a road. Outside conservation areas, a unit on a wall that faces a road is only allowed at ground-floor level.
- Removal. The unit must be removed as soon as reasonably practicable once it's no longer needed.
Conservation areas
Worcestershire has a lot of them, covering Worcester's historic centre and many town centres and villages, including Great Malvern, Pershore, Bewdley, Upton-upon-Severn and Broadway. In a conservation area, the outdoor unit can't be installed on a wall or roof that faces a road, and it can't be closer to a road than the house itself. That usually means a rear wall, a courtyard or a spot in the back garden. The installer should plan for this at the survey.
Listed buildings
Permitted development doesn't apply to listed buildings. You'll need listed building consent, and possibly planning permission, before installing anything, including the indoor unit and pipework. Doing the work without consent is a criminal offence. Talk to the council's conservation officer early. Careful proposals that keep the outdoor unit out of sight and route pipework through existing openings or mortar joints are much more likely to be approved.
Flats and leasehold homes
Blocks of flats have their own, tighter limits, including a smaller maximum unit size. Even where planning isn't an issue, most leases don't let you fix anything to an outside wall without the freeholder's written consent. If you rent, you'll need your landlord's permission.
Other things to check
- Building regulations. A new electrical circuit is notifiable work. It must be done or certified by a registered electrician.
- Covenants. Some newer estates have restrictions in the deeds or management company rules about external equipment.
- Flood risk. This isn't a planning rule, but it matters in towns along the Severn, Avon and Teme. Outdoor units should be raised above likely flood levels.
Which council to ask
If you're unsure, contact your local planning authority. In Worcestershire that's:
| Council | Covers (examples) |
|---|---|
| Worcester City Council | Worcester |
| Malvern Hills District Council | Malvern, Upton-upon-Severn, Tenbury Wells |
| Wychavon District Council | Droitwich Spa, Evesham, Pershore, Broadway |
| Wyre Forest District Council | Kidderminster, Stourport-on-Severn, Bewdley |
| Bromsgrove District Council | Bromsgrove and surrounding villages |
| Redditch Borough Council | Redditch |
For certainty, you can apply to the council for a Lawful Development Certificate, which confirms that the work is permitted development.
Checking your property
A good installer should check at the survey whether your home is in a conservation area or listed, where the outdoor unit can go, and whether it will meet the noise limit. Send us an enquiry and we'll pass it to an independent local installer, who can advise on your property. For certainty, confirm with your council.