Barnet: 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 Barnet whatever the property, because on its own it only cools.

Picking a system in Barnet therefore decides your planning path as much as your comfort. A unit that heats and cools opens up the permitted-development route on a house; one that only cools never does. Conservation-area coverage in Barnet is genuinely low (around 9% 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 Barnet flat will usually need both freeholder or managing-agent consent and planning permission.

Planning is more straightforward in Barnet than in a lot of the country: only around 9% 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 the London Borough of Barnet's planning permission for a front or side unit.

Of the 193 planning applications mentioning air conditioning or other cooling plant that Barnet has decided - every development type, of which 111 were householder applications - 88.1% were approved.

The same figures as counts are 170 approved and 23 refused.

On the 111 householder applications by themselves - homes rather than commercial schemes - the approval rate is 94.6%.

One more thing about the method: applications are identified from their own description, so the Barnet figures cover applications mentioning cooling equipment and will understate rather than overstate real activity.

Barnet has also decided 98 applications mentioning an air-source heat pump, 92.9% of them approved. That is a separate measure from the cooling figures above, since most air-source installations heat rather than cool and the two sets overlap.

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.

Ambient daytime noise across the Barnet property types we profile averages around 49 dB, and that background level matters as much as the machine's own rating: the same unit that vanishes against a main road can be the loudest thing in a quiet back garden.

Siting is the lever. Keeping the outdoor unit away from a neighbour's window and back from the boundary is what most often turns a marginal case into an approved one.

None of this is a dealbreaker: councils in Barnet approve outdoor units for homes like these all the time. Around 9% 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 1.2% 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.