Cost guides › Air conditioning
United Kingdom
Air conditioning installation cost
Installing wall-mounted split air conditioning in 3 rooms typically costs £4,500 including VAT, with most quotes between £3,500 and £5,850. That is one 3.4 kW reverse-cycle unit per room with its own outdoor unit, refrigerant pipework, condensate drains and a dedicated electrical supply. A multi-split system sharing one outdoor unit is about £2,350; concealed ceiling units in a dropped ceiling are nearer £8,800.
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Cost by region
| Location | Basic | Mid-range | Premium |
|---|---|---|---|
| London | £2,400 | £4,600 | £8,950 |
| East | £2,350 | £4,500 | £8,750 |
| North West | £2,350 | £4,500 | £8,750 |
| Scotland | £2,400 | £4,500 | £8,850 |
| South East | £2,350 | £4,500 | £8,800 |
| East Midlands | £2,350 | £4,450 | £8,750 |
| North East | £2,350 | £4,450 | £8,750 |
| South West | £2,350 | £4,450 | £8,750 |
| Wales | £2,350 | £4,450 | £8,750 |
| West Midlands | £2,350 | £4,450 | £8,750 |
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| Yorkshire and The Humber | £2,350 | £4,450 | £8,700 |
What's included
Mid-range
- One 3.4 kW wall-mounted split unit per room that both cools and heats, each with its own outdoor unit
- Insulated copper refrigerant pipes, about 5 m per unit
- A condensate drain for each indoor unit
- Core drilling through the wall, mounting the indoor unit, vacuum testing and commissioning
- A wall bracket and connection for the outdoor unit
- A dedicated power cable in conduit to each outdoor unit
- An RCBO for each unit in the consumer unit
What affects the cost
Single splits or a multi-split
One outdoor unit per room means each room runs independently and a fault only affects one room, but it needs more wall space outside. A multi-split serves several rooms from one outdoor unit and is cheaper, but everything stops if that unit fails.
Pipe runs
Our estimate assumes short runs of about 5 m. Bedrooms at the front of the house with the outdoor units at the back, or pipework that has to be boxed in through several rooms, add labour and trunking.
Condensate drainage
The indoor unit produces water that must drain away by gravity to outside or a waste pipe. Where that is not possible, a condensate pump is needed, which is extra and makes a little noise.
Type of indoor unit
Wall-mounted units are the cheapest. Ceiling cassettes and ducted units hidden in a dropped ceiling look neater but cost more to buy and need building work to conceal.
Consumer unit and supply
Each unit needs a dedicated circuit. An older consumer unit without space or modern protection may need replacing first, which adds to the bill.
Outdoor unit location
Ground-level positions or low wall brackets are simplest. High walls, flat roofs or positions needing access equipment increase the cost, and in flats you may need permission from the freeholder.
How to save
- Put the outdoor units on the wall directly behind the indoor units to keep the pipe runs short.
- Only air condition the rooms that overheat, usually loft bedrooms and south-facing rooms.
- Book the installation in autumn or winter, when installers are less busy than during a heatwave.
- Use the units for heating in spring and autumn too; a reverse-cycle unit can take load off the boiler.
Grants, tax and rules
Electrical work
A new circuit for air conditioning is notifiable work in England and Wales: it must be done by a registered electrician (Part P) or notified to building control.
VAT
Our figures include 20% VAT.
Frequently asked questions
How much does air conditioning cost to install in a UK house?
For wall-mounted split units in 3 rooms, expect around £4,500 including VAT. A single bedroom unit costs much less, but the cost per room does not fall much because each room still needs its own pipework, drain and wiring.
Can air conditioning also heat my home?
Yes. The units in this estimate are reverse-cycle, so they work as air-to-air heat pumps in winter. They heat the room quickly but do not provide hot water, so they complement rather than replace a boiler.
Who can install air conditioning?
Handling refrigerant requires an F-gas certified engineer, and the electrical connection must be done by a registered electrician or notified to building control in England and Wales. Many installers hold both qualifications.
How long does it take to install air conditioning?
A single wall-mounted unit usually takes half a day to a day. Three or four rooms typically take two to three days, depending on pipe routes and electrical work.
Is portable air conditioning a cheaper alternative?
Portable units cost far less to buy and need no installation, but they are noisy, less efficient and need a hose out of a window. For bedrooms used every summer, a split unit is quieter and cheaper to run.
How this estimate is calculated
Work hours: 33.3 · Labour: £828 · Materials: £2,924
Sources: ONS Annual Survey of Hours and Earnings, tables 14 and 15; Regione Toscana, Prezzario dei Lavori 2026 (CC BY 4.0); ECB exchange rates.