In most cases, no — you do not need planning permission for air conditioning in the UK. Domestic air conditioning installations typically fall within permitted development rights, meaning you can install without applying to your local planning authority. But there are important exceptions, and getting this wrong can create problems when you come to sell your property.
Here is a clear guide to when you do and do not need permission, based on our experience installing air conditioning across Surrey, Sussex and South London — areas with a high proportion of listed buildings, conservation areas and flats where the rules are more complex.
Standard Domestic Installations — Permitted Development
For most houses (not flats, not listed buildings, not in conservation areas), air conditioning installations fall under permitted development rights under Schedule 2, Part 14 of the Town and Country Planning (General Permitted Development) Order 2015. This means you can install without planning permission provided certain conditions are met:
- The outdoor unit is not installed on a wall or roof that faces a highway
- The installation does not exceed the volume limits for outdoor units (typically not an issue for domestic split systems)
- The unit is removed when no longer needed
- Reasonable steps are taken to limit noise and vibration
In practice, the vast majority of domestic wall-mounted split system installations on rear walls or side elevations require no planning consent whatsoever.
When You Do Need Consent
Listed Buildings
If your property is listed (Grade I, Grade II* or Grade II), you need listed building consent for any external works — including fixing an outdoor unit to the building or drilling through external walls. This applies to the indoor unit fixing as well if the installation affects the character of the listed building internally.
Listed building consent applications are made through your local planning authority. The process typically takes 8 weeks. In our experience, consent is usually granted for air conditioning in listed buildings provided the outdoor unit is positioned discreetly — in a rear courtyard, side return or on a flat roof out of public view — and fixing methods are sympathetic to the historic fabric.
We have successfully installed air conditioning in numerous listed properties across East Sussex, Surrey and West Sussex — from Grade II terraced cottages to Grade I Georgian townhouses. The key is a thoughtful approach to unit positioning and fixing methods, and a pre-application conversation with the conservation officer before submitting a formal application.
Conservation Areas
Properties in conservation areas are not automatically subject to planning permission for air conditioning — permitted development rights still apply in most cases. However, Article 4 Directions can remove permitted development rights in specific conservation areas, and some local planning authorities have taken a more restrictive approach.
Our advice: if you are in a conservation area, check with your local planning authority before installation. A pre-application enquiry (which is free or low cost) will confirm whether consent is needed. This is particularly relevant in East Sussex towns like Lewes, Rye and Battle, and in Surrey towns like Reigate and Farnham where conservation areas are extensive.
Flats and Apartments
Flats present two separate considerations. First, the planning position — external works on flats in converted houses may require planning permission as permitted development rights for flats are more restricted. Second, lease restrictions — most flat leases contain clauses about external alterations that require landlord or management company consent regardless of the planning position.
If you own a leasehold flat, check your lease before proceeding. Most managing agents will consent to a sensibly positioned outdoor unit — particularly if it is on a private balcony or in a designated equipment area. The key is to ask before installing rather than retrospectively.
Properties in Article 4 Direction Areas
Article 4 Directions remove some or all permitted development rights in specific areas. These are not common but do exist — if you are in an area with an Article 4 Direction, normal permitted development rights may not apply and planning consent may be required for external units.
What About Commercial Properties?
Commercial air conditioning installations have their own planning framework. External units on commercial premises generally require planning consent unless they fall within specific permitted development categories for commercial buildings. In practice, most straightforward commercial installations on rear elevations or roofs out of public view are either permitted development or receive consent quickly.
Our Approach
We discuss planning requirements as part of every free site survey. If your property is listed, in a conservation area, or you have any doubts about the planning position, we will tell you clearly what consent (if any) is needed and whether we can assist with the application process. We will never install in a situation where we believe consent is required without first confirming the position with you.
In our experience, planning rarely prevents a well-considered air conditioning installation — it sometimes requires a different approach to unit positioning or fixing methods, but in most cases a solution exists that satisfies both the planning requirements and the technical needs of the installation.
Call 07833 053749 or contact us online for a free site survey. We cover East Grinstead, Surrey, Sussex and South London.