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

So the system you choose changes your planning path in Lewisham, 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. Roughly 17% of Lewisham's EPC-certified homes fall inside a conservation area, concentrated in areas like Brookmill Road, Halifax, St Stephens - most addresses are outside one, but the boundary check is worth doing before committing to a wall-mounted unit.

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 Lewisham flat will usually need both freeholder or managing-agent consent and planning permission.

Lewisham lands close to the national middle on conservation coverage - about 17.1% of properties, including parts of Brookmill Road, Halifax and St Stephens. With no clear-cut high or low figure to lean on, the permitted-development answer for an outdoor unit here turns more on your exact location than the borough-wide average.

Lewisham has decided too few applications mentioning cooling equipment for us to publish a figure. Below our sample-size floor we publish nothing rather than a number that would read as more certain than the evidence behind it.

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 Lewisham property types we profile average roughly 52 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.

Nothing here is a dealbreaker. Lewisham's council approves outdoor units for homes like these routinely. Conservation-area coverage locally runs at around 17.1%, which makes this worth planning for rather than assuming. Proximity to a listed building - around 1.8% of homes here sit within 30 metres of one does not mean your own home is listed, and public data can flag a conservation-area question without answering it. Treat this as indicative guidance, not legal advice, and confirm the final position with your Local Planning Authority before installing.