Maidstone: air conditioning planning permission

Since 2025-05-29, England's permitted-development rules let a house fit an air-to-air heat pump - which heats as well as cools - without a planning application in many cases, within set size, siting and noise limits. A cooling-only air conditioning unit does not get that route and needs a full planning application in Maidstone whatever the property, because on its own it only cools.

So the system you choose changes your planning path in Maidstone, not just your comfort. The same box that both heats and cools opens the permitted-development route on a house; a unit that only cools does not. Conservation-area coverage in Maidstone is genuinely low (around 4% of EPC-certified homes), so for most addresses an external unit is a lower-friction proposition than in a heritage-dense borough - an honest advantage, not a workaround.

Flats are the sharpest exception here as everywhere in England: the permitted-development right for an outdoor unit sits with the house, not the flat, so a Maidstone flat will usually need both freeholder or managing-agent consent and planning permission.

Planning is more straightforward in Maidstone than in a lot of the country: only around 4.4% of properties sit inside a conservation area, so most houses can use the permitted-development route for an outdoor unit. Flats are still treated differently, and will usually need Maidstone Council's planning permission for a front or side unit.

We hold some decided cooling cases for Maidstone and not enough to say anything with. The sample-size floor is there precisely to stop a thin record turning into a confident-looking statistic.

What actually gets refused, and what councils attach when they approve, is a national picture rather than a local one at the volume of officer reasoning currently published. We set both out with their sample sizes: why cooling applications get refused and the conditions councils attach.

You can also compare what each council decides, where enough decisions exist to publish a figure.

The Maidstone property types we profile average roughly 44 dB of daytime background noise, and a unit is judged against that baseline rather than in the abstract.

So siting decides more than the equipment does. Moving the outdoor unit away from a neighbour's window and off the boundary line is the single change that most often rescues a borderline application.

None of this is a dealbreaker: councils in Maidstone approve outdoor units for homes like these all the time. Around 4.4% of local properties sit inside a conservation area, so it is a step to plan for rather than a formality. Being close to a listed building - around 4.8% of homes here sit within 30 metres of one is not the same as your home being listed, and public data can flag conservation status without settling it. This is indicative guidance, not legal advice: confirm the final position with your Local Planning Authority before you install.