Richmond upon Thames: 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 Richmond upon Thames whatever the property, because on its own it only cools.

In Richmond upon Thames, the system you choose is a planning decision as much as a comfort one. An air-to-air heat pump on a house qualifies for permitted development because it does both jobs; a unit that only cools is excluded from that route entirely. Richmond has one of the highest conservation-area densities of any London borough, and where a wall-mounted condenser would be refused, councils here will often accept a more discreetly sited or water-cooled system instead.

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 Richmond upon Thames flat will usually need both freeholder or managing-agent consent and planning permission.

Roughly 32.1% of properties in Richmond upon Thames fall inside a conservation area - Richmond, Twickenham and Ham among the named ones, a genuinely high figure. Inside those boundaries the permitted-development route a house would otherwise rely on is narrowed or withdrawn, so a front or side-facing unit will usually need the London Borough of Richmond upon Thames's sign-off.

90.5% of the 42 planning applications mentioning air conditioning or other cooling plant that Richmond upon Thames has decided were approved, a figure covering all development types and including 15 householder applications.

The same figures as counts are 38 approved and 4 refused.

A householder-only rate would be the more useful number, and Richmond upon Thames has not yet decided enough of them for one: 15 is below the sample size we publish a percentage from.

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

Richmond upon Thames has also decided 33 applications mentioning an air-source heat pump, 87.9% 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.

The Richmond upon Thames property types we profile average roughly 58 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 Richmond upon Thames approve outdoor units for homes like these all the time. Around 32.1% 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 3.8% 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.