How much does air conditioning cost in the UK?
The short answer
In the UK in July 2026, a single-room wall-mounted split system costs roughly £1,500 to £3,000 fitted. A two-room multi-split runs £2,800 to £4,500. A three or four room system is £3,500 to £7,000. Ducted whole-home systems start around £6,000 and can pass £15,000.
A £2,500 government grant is available for air-to-air heat pumps under the Boiler Upgrade Scheme, but only where the system replaces your fossil fuel heating entirely. It does not apply to a single unit added for summer cooling.
See whether the £2,500 grant applies to your home. Five questions, no account.
Check eligibilityWhat you actually pay in 2026
Air conditioning in a UK home almost always means a split system: one outdoor condenser, one or more indoor units, and refrigerant pipework between them. The price is driven by how many rooms you are cooling, how far the pipework has to run, and where you live.
The ranges below reflect fitted prices reported across UK trade and quote-comparison sources in the first half of 2026. They include the unit, refrigerant pipework, condensate drain, commissioning and F-Gas certification.
| System | What it covers | Typical fitted cost |
|---|---|---|
| Portable unit | One room, no installation | £200 to £500 |
| Single split | One room, one indoor unit | £1,500 to £3,000 |
| Two-room multi-split | Two indoor units, one condenser | £2,800 to £4,500 |
| Three to four room multi-split | Three or four indoor units | £3,500 to £7,000 |
| Ducted or whole-home | Concealed units, ceiling outlets | £6,000 to £15,000+ |
Figures as at July 2026. Sources: Checkatrade, MyBuilder and BestBuilders. Links in the sources section below.
A useful way to read that table: the outdoor condenser is roughly a third of the cost of a single-room install. That is why adding a second room to an existing multi-split condenser is far cheaper than fitting a second standalone system, and why installers will push you to plan the whole house up front even if you only fit two rooms this year.
Checkatrade breaks a typical 12,000 BTU wall-mounted system down as around £750 for the unit and around £1,150 for installation, which is a reasonable mental model for the split between kit and labour.
Where you live changes the number
London and the South East run consistently above the national average, by roughly 20 to 30 per cent on comparable jobs. That is labour rates, parking, access and the practical difficulty of siting a condenser on a terraced or flatted property, not the price of the equipment, which is broadly national.
If you are in a London borough, budget at the top of each range and check the planning position before you get quotes. Several boroughs treat external units on front or side elevations as needing consent, and conservation areas remove permitted development rights that would otherwise apply.
What size unit do you need?
Sizing is the decision that most affects whether you are happy with the result. Undersized and the room never gets cool. Oversized and the unit short-cycles: it hits temperature fast, switches off before it has pulled moisture out of the air, and leaves the room cold and clammy.
The rule of thumb used across the UK trade is about 0.1 kW of cooling capacity per square metre of floor area, rising to about 0.15 kW per square metre for kitchens and rooms that catch full afternoon sun.
| Room | Typical capacity | Approximate BTU |
|---|---|---|
| Small bedroom | 2.0 to 2.5 kW | 7,000 to 9,000 |
| Large bedroom or home office | 2.5 to 3.5 kW | 9,000 to 12,000 |
| Living room | 3.5 to 5.0 kW | 12,000 to 18,000 |
| Open-plan kitchen and living | 5.0 to 7.0 kW and above | 18,000 to 24,000+ |
Add roughly 15 to 20 per cent for older or single-glazed properties, about 20 per cent for kitchens, and about 10 per cent for each extra metre of ceiling height above standard.
The £2,500 grant: what it does and does not cover
This is where most cost guides stop short, and where the numbers change materially.
Air conditioning and an air-to-air heat pump are the same machine. A modern split system runs in reverse in winter and heats the room. In April 2026 the government made air-to-air heat pumps eligible for a £2,500 grant under the Boiler Upgrade Scheme, alongside the existing £7,500 for air-to-water and ground source systems.
The grant is for heating, not cooling, and the rules rule out the most common purchase. The system must replace an existing fossil fuel heating system, meaning gas, oil or LPG, or direct electric heating. Your boiler must come out; you cannot keep it as a backup or run a hybrid. The air-to-air system must become the property's primary heating source. Scheme rules require an indoor unit in every occupied room, so a single bedroom unit will not qualify. It is England and Wales only, one grant per property, residential only. An MCS certified installer applies on your behalf and deducts the grant from your invoice, so you never handle the money.
Read that list again and the cost picture inverts. If you want one unit in the bedroom for August, you pay £1,500 to £3,000 and get nothing from the government. If you are replacing your heating anyway and you fit a whole-home system, you pay £3,500 to £7,000 and take £2,500 off it.
| Scenario | Gross cost | Grant | Net |
|---|---|---|---|
| One bedroom unit, boiler stays | £1,800 | £0 | £1,800 |
| Two rooms, boiler stays | £3,500 | £0 | £3,500 |
| Whole home, three rooms, boiler removed | £5,000 | £2,500 | £2,500 |
| Whole home, four rooms, boiler removed | £6,500 | £2,500 | £4,000 |
Illustrative only. Grant eligibility is confirmed by your installer, not by this table.
One important caveat on timing. The regulations are in force, but MCS product certification for air-to-air systems is still catching up, and installers cannot raise a compliant grant voucher until certified products appear on the MCS Product Directory. Our grant status page tracks the current position.
What it costs to run
At the Ofgem price cap for 1 July to 30 September 2026, electricity is 26.11p per kWh.
For cooling, a typical 2.5 kW inverter split drawing 0.7 to 0.8 kW in steady operation costs roughly 18p to 21p an hour. A larger 3.5 kW unit is closer to 26p an hour. Over a hot week of evening use that is a few pounds. All-day use across several rooms is where it adds up, which is why the efficiency rating on the unit is worth paying attention to.
For heating, the comparison is closer than most people expect. Air-to-air systems tested to EN 14825 typically return a seasonal coefficient of performance, or SCOP, of 3.0 to 4.0. At SCOP 3.5 a unit delivers heat at roughly 7.5p per kWh. A 92 per cent efficient gas boiler at the current cap of 7.33p per kWh delivers heat at roughly 8.0p per kWh.
So a well-specified air-to-air system heats at broadly the same cost as gas, and a poorly specified one costs more. The variables that decide it are the SCOP of the unit you buy, how well insulated the property is, and your electricity tariff. Removing the gas standing charge of 29.04p a day, about £106 a year, matters too if you are going fully electric.
For the full running cost maths, including tariffs, SCOP break-even and the grant netted off, see our air to air heat pump cost guide.
Why the cheapest quote is often not legal
Under F-Gas regulations, the refrigerant side of a split system must be installed by an F-Gas certified engineer. That is a legal requirement, not a trade preference. A quote several hundred pounds below the others usually means either an uncertified installer or a pre-charged system installed outside the regulations.
An F-Gas certified installation typically costs £200 to £400 more than an unregulated one. Ask for the certificate number before you book. If you intend to claim the grant you need an MCS certified installer as well, which is a separate certification.
How to reduce what you pay
Plan the whole house and fit in phases. Size the condenser for the eventual system and add indoor units later, because retrofitting a bigger condenser is expensive.
Get three quotes. Price variance on identical specifications is routinely 30 per cent.
Book out of season. October to March is quieter and installers price accordingly.
Compare brands on SCOP rather than badge. Mitsubishi Electric and Daikin carry a 15 to 25 per cent premium over Toshiba or LG at equivalent output. Sometimes that buys better efficiency and quieter operation, sometimes it buys the badge.
Check grant eligibility before you specify. If you are replacing your heating anyway, the grant-eligible route may be cheaper net than the smaller system you were planning.
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