Air con for flats
Air conditioning for London flats
Yes, you can usually get air conditioning in a London flat, but you need two things first: written consent from the freeholder or managing agent, and somewhere legal for the outdoor unit. Where there is no outside space, an all in one unit with two small holes through the wall can work instead.
Start a quote
Air conditioning quote
Tell us about the rooms. The installer will confirm sizes and positions on a free survey.
- 01The space
- 02Your building
- 03What you want
- 04Your details
The space
Which rooms need cooling?
Pick all that apply.
The space
How many indoor units do you think?
Your building
What type of property?
Your building
Where could the outdoor unit go?
Your building
What are the outside walls?
What you want
Do you want it to heat as well?
Most split systems can run in reverse as an air to air heat pump.
What you want
When would you like it fitted?
What you want
What is the postcode?
So the right engineer for your area picks it up.
Your details
Your quote is confirmed at a free survey
Unit sizes depend on room size, windows, insulation and where the outdoor unit can go. The installer checks all of that in person before giving a fixed price.
You need this when
- Your top floor flat is hotter than the street on summer evenings
- A west facing living room bakes from 3pm onwards
- Windows face a busy road or flight path so you cannot leave them open at night
- Your new build flat has large windows that will not open far
- Your lease lets you apply for alterations and you want to do it properly
Why flats are the normal case in London
London is a city of flats. The 2021 Census found that 54% of London households live in a flat, maisonette or apartment, against about 22% across England and Wales. That covers Victorian houses split into two or three flats, red brick mansion blocks in Marylebone, Maida Vale and Battersea, council built estates and the glass towers of Canary Wharf and Nine Elms.
Flats also overheat more than houses. The Greater London Authority's heat risk study found higher risk towards the centre of London, in boroughs such as Camden, Islington, Hackney and Tower Hamlets, partly because they have more flats. A top floor flat gets the heat from the roof and from the flats below.
Freeholder consent comes before anything else
If you own a leasehold flat, you usually own the inside of the flat but not the outside walls, roof or structure. Fixing an outdoor unit or drilling a pipe hole almost always needs the freeholder's written consent, often through a formal licence for alterations. Managing agents for mansion blocks commonly ask for:
- the make, model and size of each unit
- a drawing or photo showing the outdoor unit position
- a noise figure at the nearest window
- how the condensate will drain
- proof of F-gas certification and insurance
Renting? Then you need your landlord's permission, and they may need the freeholder's too. Starting without consent can mean being told to remove the system.
Planning rules are tighter for flats
Permitted development for heat pumps applies to a house or a block of flats, not to one flat on its own. A block of flats only gets one unit in total, and the outdoor unit must be no more than 0.6 cubic metres. The building must be wholly flats, so a block with shops on the ground floor does not qualify. The unit must also be used for heating, not only cooling, and it cannot be on a listed building.
In practice, that means most flat owners need a planning application, especially in central boroughs where Westminster, Kensington and Chelsea, Camden and Islington are largely covered by conservation areas. We prepare the details the council asks for so the application is clear first time.
Options when there is nowhere for an outdoor unit
Not every flat has a rear wall, roof or lightwell you are allowed to use. The options then are:
- All in one (monobloc) units: the whole system sits inside on the wall and breathes through two holes about 15 to 20cm wide, according to the Energy Saving Trust. They are louder inside than a split system but avoid an outdoor box.
- A longer pipe run to a permitted spot, such as a shared roof, if the freeholder agrees.
- Portable units as a stop gap, though the hose makes them inefficient and they rarely seal in a sash window.
We will tell you honestly which one fits your flat after the survey.
What affects the price
Flat installs often cost more in time than a house because of access, longer pipe runs to a permitted spot and the consent paperwork. The price is confirmed after the survey once the outdoor unit position is agreed.
| What | Price |
|---|---|
| Split system, one room | about £1,900 for a single room air to air system (Energy Saving Trust typical figure) |
| All in one wall unit with no outdoor box | quote on survey |
| Roof access, scaffold tower or abseil for high level units | quote on survey |
| Licence for alterations or freeholder fees | set by the freeholder |
| Planning application fee | set by the council |
No prices are shown on this site. Every job is priced after a look at it, by photo or a visit.
How the job runs
-
We help you find the alterations clause and tell you what the freeholder or managing agent is likely to ask for, such as drawings, a noise figure and the unit's position.
-
We look at the rooms, the outside walls, any balcony, roof or lightwell, and where condensate can drain inside the flat.
-
You get a short pack for the freeholder and, where needed, the council: unit model, size, position, pipe route and the noise calculation.
-
Work starts after written consent. Pipes are kept inside where possible, the outdoor unit is fixed to the agreed spot and the system is commissioned and tested.
Every price is agreed in writing before work starts.
Start a quoteCan I install air conditioning in a leasehold flat?
Usually yes, with the freeholder's written consent. Check the alterations clause in your lease, then apply with the unit details, position and noise figure. Do not drill anything until consent is in writing.
Do I need planning permission for air con in a flat?
Most of the time, yes. Permitted development only allows one heat pump per block of flats, it must also heat, and it does not apply to listed buildings or mixed use blocks.
Can I have air conditioning in a rented flat?
Only with your landlord's permission, and the landlord may need the freeholder's consent too. A portable unit needs no fixing, so it is the usual stop gap for renters.
Is there air conditioning without an outdoor unit?
Yes. All in one units sit inside on an outside wall and use two small ducts through it. They avoid an outdoor box but are louder in the room and less powerful than a split system.
Where
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Air con for flats
Send it through and get a reply
Describe the rooms or the problem in a sentence. Photos of the wall and the outside space help if you can text them later.