As a September 2026 budgeting illustration, a straightforward single-room wall-mounted split installation in the UK often lands around £1,500 to £3,000 including VAT. Comparable London work more often sits around £1,800 to £3,500 once parking, access and labour are honest. Long pipe runs, condensate pumps, electrical upgrades, scaffolding and awkward outdoor positions push both bands up. These are planning illustrations, not a tariff. Only a written site survey settles your number.
What the single-room band actually assumes
For one small domestic room, the normal starting point is one indoor wall unit connected to one outdoor condenser. Across much of the UK, a simple surveyed install may still be budgeted at roughly £1,500 to £3,000 including VAT. London labour, parking, congestion access and logistics commonly move a similar job towards roughly £1,800 to £3,500.
That band assumes a short pipe run through an outside wall, a condensate route that can fall to a drain, a consumer unit with a spare way, and an outdoor spot you can reach without scaffold. It assumes the quote includes the equipment, the standard pipe allowance, brackets or feet, an isolator, pressure testing, evacuation, commissioning and VAT. A national from-price that skips those lines is marketing.
Room size alone does not set the kilowatts. Glass, orientation, a roof overhead and an open-plan volume change the load. A 12 square metre loft bedroom with a south roof light can need more capacity than a larger north-facing room downstairs. Pair this page with the home installation guide and the wall-mounted installation guide when you are asking installers to price the same job.
- Ask whether VAT, delivery, commissioning and waste removal are included.
- Check the stated make, model, output and warranty rather than comparing headline totals.
- Treat any price given without a survey or detailed questions as provisional.
Two rooms is not twice one room
A second room can be a second split, with its own outdoor unit, or a multi-split with two indoor units on one outdoor. Two separate splits double the outdoor plant, the brackets and often the electrical work. A multi-split saves a second condenser and can be the tidier elevation, but the outdoor unit is larger, the pipework is two runs, and a fault on that one outdoor stops both rooms.
Two or three rooms often take the project into several thousand pounds. The jump is not a neat multiple of the single-room band. The second indoor may be a short run or a long one through a loft. One room may drain by gravity while the other needs a pump. Ask for the price of each room on its own and the price of doing them together, so you can see what the second room actually adds.
Whole-house cooling, four or five indoors, is a different job again. Outdoor siting, noise at bedroom windows, and the single-phase supply at the house start to matter as much as the fascia you liked in a brochure. Do not take the one-room illustration and multiply it by the number of bedrooms.
The lines that push a quote out of the band
Short, accessible pipework through an external wall is usually the least expensive arrangement. Long refrigerant runs, a route through a loft or several rooms, condensate pumps, roof access, scaffolding, core drilling through concrete or stone, and concealed services all add labour or materials. A pump is a small part and a lasting maintenance item. Scaffold for a high outdoor unit can cost as much as a chunk of the equipment.
Making good is where cheap quotes go quiet. Cutting a hole, clipping trunking, and leaving you to plaster and paint is a different price from filling, sealing and painting the pipe run. Ask who fills the core hole inside and out, who supplies the trunking colour, and what happens if a floorboard or a ceiling rose has to come up.
Noise-sensitive spots and landlord rules change the design, not just the paperwork. Moving the outdoor unit off a bedroom wall, adding anti-vibration feet, or routing pipes the long way around a neighbour's window is real labour. A flat that needs a licence to alter can add weeks. That delay is not inside the equipment price.
London is access and time, not a postcode tax
A London postcode does not by itself justify a round premium. What does move the figure is parking and permits, a street you cannot leave a van on, a mansion block with a goods lift and booked hours, a pavement elevation that needs a tower, and labour that spends the morning getting to the wall. Those are why comparable London work more often sits around £1,800 to £3,500 for a straightforward single room, and why a difficult London job leaves that band.
Ask the quote to say how access is priced. A figure that assumes a van outside the door is not the figure for a red route or a block that only allows work between 10 and 4. If two London quotes are hundreds apart, read the access line and the pipe allowance before you read the brand.
Electrics, drains and who is allowed to touch the gas
The electrical supply may need work that is not in a headline air conditioning price. The installer should state whether a new circuit, an isolator, a consumer unit change or a separate electrician visit is included. A healthy board with a spare way is a different job from a full board with no room for another circuit. Permanent splits are not specified to plug into a normal socket.
Condensate has to leave the building. A gravity fall to an outside spout or a waste is the simple case. A pump up to a soil stack, a run across a ceiling, or a drain that would otherwise drip onto a path is extra equipment and a future call-out if it fails. The quote should name the route.
The company that opens the refrigerant circuit needs the right F-gas company certification, and the people doing the regulated tasks need the right qualifications. That is a legal condition of the work, not a luxury line you can delete to save money. A lower quote that is vague about who handles the gas is not a bargain until that is in writing.
Cooling-only and reversible are not the same purchase
Many modern split air conditioners are reversible air-to-air heat pumps. They cool in summer and can heat in cooler weather. Energy Saving Trust describes that heating role: the indoor units blow warm air, and these systems do not normally give you hot water. A cooling-only unit is a different product. Do not assume it has the same planning treatment or the same use across a year.
In England, the Class G permitted development conditions for a domestic air source heat pump include a condition that the unit is not used solely for cooling. A cooling-only system does not satisfy that condition. A reversible system still has to meet every other limit, and flats often still need an application. Planning, the lease and the technical standard for the actual proposal all have to be checked. None of that is included just because a quote mentions a heat pump.
How to budget without treating the band as a price
Request a written scope showing equipment model codes, pipe length allowance, trunking, condensate route, outdoor mounting, electrical work, controls, commissioning and making good. Ask what event would create an extra charge: extra metres of pipe, a pump, a board change, scaffold, or decorating. Use the quote form with photos of the indoor wall, the outdoor elevation and the consumer unit so replies are about your house.
Running cost sits beside the install price. Compare efficiency for the same capacity, then remember electricity use depends on weather, setpoint, insulation, glazing, occupancy and hours. A slightly cheaper installation is not necessarily cheaper over the life of the system. The Boiler Upgrade Scheme is not a way to fund cooling-led air conditioning. Budget the install as a paid job, then compare written scopes.
Frequently asked questions
Why does air conditioning cost more in London?
Parking, congestion, restricted working hours, difficult access and higher labour overheads can all contribute. The effect varies by site, so a London postcode alone should not justify an unexplained premium.
Can I get an accurate price from room dimensions?
Dimensions help, but a proper selection should also consider glazing, orientation, insulation, occupancy, equipment heat gains and the proposed pipe and condensate routes.
Is VAT normally included in advertised prices?
Not always. Ask for a VAT-inclusive total and check whether electrical work, access equipment, commissioning and disposal are included.
How much to install air conditioning in a UK house?
A single straightforward room often still budgets in the £1,500 to £3,000 including VAT illustration band outside London, with London commonly higher. Whole-house multi-room work is a different order of magnitude once several indoors and outdoor plant are surveyed.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.