Quick answer: for a single wall-mounted unit cooling and heating one room, most UK homeowners pay somewhere around £1,500 to £3,000 supplied and installed. A two-room multi-split typically lands around £3,000 to £4,500, and a three or four-room system around £4,500 to £7,500. Ceiling cassettes and concealed units cost more than wall-mounted ones. Those are typical UK market ranges rather than a quote — the only way to get a real number is a survey, because the price is driven far more by your building than by the box on the wall.
What actually drives the price
Two houses can get quotes hundreds of pounds apart for what looks like the same system. It is almost always one of these:
- How far the indoor unit is from the outdoor one. This is the big one. Refrigerant pipework, cabling and condensate drain all have to run between them, usually hidden. A bedroom on the same wall as the condenser is a short, tidy job. A room on the other side of the house, three floors up, is not.
- How many rooms. A multi-split runs several indoor units from one outdoor condenser. Each additional indoor unit adds cost, but less than a second complete system would — so two rooms at once is usually better value than two rooms a year apart.
- The type of indoor unit. Wall-mounted is the most economical. Ceiling cassettes, floor units and concealed ducted systems cost more to buy and considerably more to fit, because they involve ceilings, joists and builder’s work.
- Where the outdoor unit can go. Ground level against an external wall is straightforward. A flat roof, a balcony, or anything needing scaffolding or a bracket at height adds labour and access costs.
- The electrical supply. Most installs need a dedicated circuit from the consumer unit. If your board is full or needs upgrading, that is a real cost and an honest installer will tell you before quoting, not after.
- The brand and efficiency grade. There is a genuine spread between premium and budget. We fit both Mitsubishi Electric and Midea for exactly this reason — the higher-end units are quieter and more efficient, the budget ones still perform well, and which is right depends on the room and the use.
Typical UK ranges by setup
Treat these as a sense-check on a quote, not as prices:
- One room, wall-mounted — around £1,500 to £3,000. A bedroom, home office or garden room.
- Two rooms, multi-split — around £3,000 to £4,500.
- Three to four rooms, multi-split — around £4,500 to £7,500.
- Ceiling cassette or concealed — expect a meaningful premium over wall-mounted for the same coverage, driven mostly by installation labour.
One thing worth checking with any installer: air conditioning is generally treated differently from solar panels and air-source heat pumps for VAT. Solar currently carries 0% VAT on residential installations, but comfort cooling usually does not qualify for that relief, so assume 20% VAT is in the figure unless your installer confirms otherwise. Ask for it to be shown separately on the quote.
What it costs to run
The running cost surprises people in both directions.
Modern inverter units are far cheaper to run than the plug-in air conditioners people buy in a heatwave, because they modulate rather than switching hard on and off. Cooling a single bedroom overnight is typically a matter of pennies per hour rather than pounds.
The part that gets overlooked is heating. An air conditioning unit is an air-to-air heat pump run in reverse, and in mild weather it delivers roughly three to four units of heat for every unit of electricity it uses. For a room you only heat occasionally — a home office, a converted garage, a conservatory — that is usually cheaper than running electric panel heaters, and quicker than heating the whole house from the boiler to warm one room. We have written more on using air conditioning for heating if that is the part you are weighing up.
If you already have solar, the fit is a good one: the hottest, sunniest hours are exactly when your panels are generating hardest and when the cooling demand peaks. Pairing air conditioning with solar PV, and especially with battery storage, means a good share of the cooling runs on electricity you have already generated.
Questions worth asking before you accept a quote
- Is the engineer F-Gas registered? Anyone handling refrigerant legally must be. Ask, and ask to see it.
- Is the price fixed after the survey, or an estimate? A price given without anyone visiting is an estimate, whatever it says at the top.
- Does it include the electrical work? Including any consumer unit changes, and the certification for them.
- Where exactly will the outdoor unit sit, and how loud is it? Get the decibel figure and the position agreed in writing — this is the most common source of regret, and of complaints from neighbours.
- What does the warranty cover, and does it require annual servicing to stay valid? Many manufacturer warranties do.
- Is making good included? Filling and finishing where pipework passes through walls.
Why we do not publish a single price
We could put a headline number on this page and it would probably get more clicks. The trouble is that it would be wrong for most people who read it, because the pipe run and the electrics decide the price and we cannot see either from here.
So we survey first, free and without obligation, then give you a fixed price for the system we actually recommend. If your room is a poor candidate — a west-facing glass box with nowhere sensible to put a condenser, say — we would rather tell you that than sell you something that disappoints. That approach is most of what our customers write about us.
Next steps
You can read more about the systems we install, from single wall-mounted units to multi-split setups, on our air conditioning page. If you would rather just talk it through, call us on 01202 985888 and we will arrange a free survey — we are based in Wimborne and cover Dorset, Hampshire and Wiltshire.