Air Conditioning Planning Permission UK 2026: Complete Guide

The short answer

Most home air conditioning installations in the UK do not need planning permission. The outdoor unit is usually covered by permitted development rights, which allow certain changes to your home without a full planning application. There are conditions the installation has to meet, and some situations where you do need permission. We check all of this on the survey, so you know where you stand before any work is booked.

What permitted development covers

Permitted development is the set of rules that allow small, sensible changes to a house without applying to the council. For an air conditioning or air-source heat pump outdoor unit, the conditions are about keeping the unit reasonable in size and well positioned. In broad terms, they cover:

The exact figures are set nationally, are occasionally updated, and can be interpreted slightly differently by individual councils. We work to the current rules and confirm your specific situation rather than quoting numbers that might change.

When you do need permission

There are a few clear cases where an application or extra consent is needed:

Planning is not the only thing to consider

Even where you do not need planning permission, the work still has to be done properly and safely. Handling refrigerant is regulated separately under F-Gas rules, which is why it must be done by a certified engineer. All of our engineers are F-Gas certified, so that side is covered as standard.

What we do about it

When we survey your home, we look at where the outdoor unit can go and flag anything that affects planning. If your property is listed or in a conservation area, or if the only sensible position is front-facing, we tell you honestly what is involved before you commit. Where permission is needed, we point you to the right process rather than pressing ahead and hoping.

If you are thinking about an installation and want to know where you stand, request a quote and we will assess it on the survey. Our loft conversion guide and our guide to air conditioning noise levels cover two of the things most closely tied to planning.

Planning permission: common questions

Do I need planning permission for a unit in my back garden?

Usually not, provided it meets the permitted development conditions on size, position and distance from the boundary. We confirm this on the survey.

I live in a listed building. What is different?

You will normally need listed building consent for external work, and the position of the outdoor unit is important. We talk you through it before booking anything.

Do flats need permission?

Often yes, and you will usually need your freeholder or managing agent's agreement as well. It is worth checking early.

How can I check the rules for my address?

Your local council's planning pages are the definitive source, and we are happy to advise based on what we find at the survey.