Air conditioning for extensions and kitchen-diners across London
In Westminster, a side wall of a single-storey extension is usually the neatest place for the indoor unit. An extension in Westminster with a roof lantern or large glazed doors can overheat quickly on a sunny afternoon. In London, heat soaks into brick and concrete during the day and comes back out at night, which is when it is hardest to sleep.
Prices in London
Guide prices around London run from £1,895 to £5,845 per space including VAT. That is above the UK middle, mainly because labour and access cost more in London. The biggest variables are the pipe route, access for the outdoor unit and the state of the consumer unit, all of which the survey settles. As an example, the Large single option (one 5–7 kW unit for a large glazed space) would typically be £2,695–£3,745 here.
Single unit
One 3.5–5 kW unit for a medium extension.
Large single
One 5–7 kW unit for a large glazed space.
Twin units
Two indoor units on a multi-split for long or L-shaped spaces.
Guide prices show VAT at 20%. HMRC treats most fixed air conditioners and air-to-air heat pumps installed in homes as energy-saving materials, zero-rated until 31 March 2027 when we supply and fit them. If your installation qualifies, your quote shows 0% VAT and a lower price. Servicing, repairs, cleaning and controls are charged at 20%.
Planning and permissions
In England, most houses can have an outdoor unit under permitted development if it is no larger than 1.5 m³, meets the MCS 020(a) noise limit of 37 dB(A) at the nearest neighbour's window, and there are no more than two on a detached house or one on other houses. Listed buildings need consent.
The survey
Surveys in London cover heat gain, pipe routes, electrics, access and noise to the nearest neighbour, so surprises on the day are rare. The free survey is where the real price is set: room measurements, pipe and drain routes, electrical checks and the outdoor unit position, all written into your quote.
What is included
Included with air conditioning for extensions and kitchen-diners across London:
- Pressure test, vacuum and commissioning
- Placement clear of the hob and oven
- Handover of the remote or app
- Free survey with glazing and roof heat-gain check
- Hidden routes during the build, or neat surface routes after
- One or two units sized for the whole space
Districts in London
Pick your district for local details, or see every service in London.
- Islington
- Westminster
- Bexley
- Barking
- Archway
- Sutton
- Croydon
- Ilford
- Enfield
- Harrow
- Tottenham
- Walthamstow
- Dagenham
- Becontree
- Romford
- Hayes
- Wembley
- Fulham
- Edmonton
- Southall
- Putney
- Battersea
- Canary Wharf
- Purley
- Peckham
- Chingford
- Uxbridge
- Wimbledon
- Stamford Hill
- Brixton
- Hounslow
- Finchley
- Cricklewood
- Mitcham
- Feltham
- Acton
- Beckenham
- Chelsea
- Streatham
- South Croydon
- Leytonstone
- Eltham
- Morden
- Carshalton
- Catford
- Willesden
- Canning Town
- Holloway
- Welling
- Shepherds Bush
- Surbiton
- Greenford
- Heston
- Stratford
- Chiswick
- Thamesmead
- Ruislip
- Greenwich
- Barnet
- Kilburn
- Wood Green
- Muswell Hill
- Bow
- Highbury
- Camden Town
- Northolt
- Coulsdon
- Hornchurch
- Blackheath
- Isleworth
- Chalk Farm
- New Malden
- Hanworth
- Woodford Green
- Hadley Wood
- Richmond
- Barnes
- Notting Hill