Do You Need Planning Permission for Air Conditioning?

The short answer

For a lot of houses, fitting an outdoor air conditioning unit does not need a planning application. It falls under permitted development, which is a set of rights that allow certain changes to a home without applying for permission first.

Permitted development is conditional, though, not automatic. It comes with rules about where the unit goes and how it performs, and those rights are reduced or removed altogether on some buildings. Brighton and Hove happens to have a lot of the buildings where they are reduced: conservation areas, listed buildings, and flats and maisonettes are all common here.

So the honest answer is usually "no, but it depends on the property", and it is worth checking before anything is ordered.

The question is rarely whether air conditioning is allowed. It is whether this unit, on this building, in this position, is allowed.

What the permitted development conditions actually cover

The detailed thresholds sit in planning legislation and guidance, and they are updated from time to time, so it is more useful to know the categories of condition than to memorise figures. Broadly, the rules deal with:

• Where the unit sits on the building. Positions on walls or roof slopes that front a highway are commonly restricted, as are positions on a roof or above a certain height.
• How close it is to the site boundary. There is normally a minimum distance to keep to.
• The size of the unit. Both the physical volume of the box and, in some cases, how many you fit.
• Noise at the boundary. The unit has to meet a noise limit measured at a neighbouring property, which is why siting and unit choice matter so much.
• Restoring things afterwards. If the equipment is no longer needed, it is generally expected to be removed and the wall or roof made good.

Treat any specific number you read online, on an installer's site or anywhere else, as something to confirm with the council rather than rely on.

When permitted development probably does not apply

Three situations come up constantly around here.

Listed buildings. Work to a listed building normally needs listed building consent, which is a separate thing from planning permission and can apply to the inside of the building as well as the outside. Fixing an outdoor unit to the fabric of a listed building is not something to do on an assumption.

Conservation areas. Permitted development rights are commonly restricted in conservation areas, and some are covered by an article 4 direction that removes them further. Brighton and Hove has a large number of conservation areas, so this catches a lot of otherwise ordinary houses.

Flats and maisonettes. The permitted development rights that cover this kind of installation generally apply to houses. If you live in a flat or a maisonette, a planning application is usually needed even where an identical unit on the house next door would not require one.

Leaseholders: planning is only half the question

If you hold your home on a lease, you will very probably need the freeholder's or the managing agent's written consent as well, and that is true whether or not planning permission is required.

Planning consent and freeholder consent are separate permissions and one does not stand in for the other. Your lease will usually say something about alterations to the structure or the exterior, so it is worth reading that early rather than after a survey.

Who actually decides

Brighton & Hove City Council is the planning authority for Brighton, Hove and Woodingdean. If your property sits outside that area, it will be your own local planning authority.

Most councils run a formal enquiry service that will tell you whether permission is needed for a specific proposal at a specific address, and some will issue a certificate confirming a scheme is lawful development. A written answer from the council is worth considerably more than an opinion from anyone else, ourselves included.

This article is general guidance to help you ask the right questions. It is not a planning decision and it is not a substitute for one.

Where we come into it

We are not planning consultants, and we will not tell you an application is unnecessary when it might well be. What we can do is help you avoid the problem in the first place.

At survey we look at where the outdoor unit could realistically go, what it will sound like from a neighbour's window, and whether a different position or a different unit would keep you clear of the issues above. On a flat, a listed building or a house in a conservation area, we will say plainly that the council is the next call before anything is ordered.

If you are still working out what a system would involve, our air conditioning installation page covers what a full install includes.

We are based in Woodingdean and cover Brighton, Hove, Worthing, Lewes, Shoreham-by-Sea, Haywards Heath, Seaford, Burgess Hill and surrounding Sussex towns. Call 01273 911551 and we will talk it through.