How Much Does Home Air Conditioning Installation Cost in the UK?

Typical price ranges for a fitted system

For a single wall-mounted split system cooling one room, most UK homeowners pay somewhere between £1,500 and £3,000 fully installed. That covers the indoor unit, the outdoor condenser, up to a few metres of pipework, electrical connection, commissioning and VAT. The lower end is a compact unit in a straightforward location; the upper end is a quieter, more efficient model with a longer or trickier pipe run.

A multi-split, where one outdoor unit serves two to four rooms, usually lands between £3,500 and £8,000 depending on how many indoor units you want and how far apart the rooms are. Whole-house ducted or ceiling cassette systems in larger houses start around £8,000 and can go well beyond £15,000 once you factor in ceiling work and making good.

Treat these as guide figures rather than promises. A proper survey is the only way to get a fixed price, and any installer quoting a firm number without seeing the property is guessing.

• Single split, one room: roughly £1,500 to £3,000
• Multi-split, two to four rooms: roughly £3,500 to £8,000
• Ducted or cassette whole-house: £8,000 upwards
• Extra indoor unit added to a multi-split: typically £800 to £1,500 each

What actually drives the cost

The equipment is usually less than half the bill. Labour, pipework, brackets, electrical work and the refrigerant handling are where the money goes, and every one of those is shaped by your building. A ground-floor room with an outside wall and space for the condenser on a patio is the cheapest job going. A second-floor flat where the pipe has to run 12 metres to a rear courtyard, with a condensate pump because there is nowhere for the drain to fall, is a different day's work.

Unit size matters too. A small bedroom needs around 2.5 kW of cooling; a large open-plan kitchen and living room with a south-facing glass extension might need 5 kW or more, and bigger units cost more to buy. Efficiency rating, noise level and brand all nudge the price, and the difference between a budget make and a premium Japanese brand can be £400 to £800 on a single split.

Electrics catch people out. Most single splits run from a dedicated 16 amp circuit, and if your consumer unit has no spare way or is an older fuse board, you may need an electrician before the installer can sign the job off. Budget £150 to £400 for a new circuit if one is needed.

Why Fulham and South West London jobs cost a bit more

The housing stock around Fulham is mostly Victorian and Edwardian terraces, many split into flats. Solid brick walls take longer to core-drill than modern blockwork, and getting a condenser into a rear garden or onto a flat roof often means a longer pipe run, extra brackets or a scaffold tower for a day. Parking permits and congestion charge are small line items, but they do add up across a two-day install.

Planning is the other local factor. Much of Fulham sits in conservation areas and some streets have Article 4 directions, which means an outdoor unit visible from the road may need planning permission. If you are in a leasehold flat, the freeholder or managing agent will almost always need to consent to a condenser on shared walls or roofs. Neither of these adds directly to the installer's price, but a planning application costs around £250 and can add weeks to the timeline, so ask about it early.

• Solid-wall core drilling and longer pipe runs add labour time
• Rear-of-terrace condenser positions may need a scaffold tower
• Conservation areas and Article 4 streets can trigger planning requirements
• Leasehold flats need freeholder consent before work starts

Running costs and what to budget after installation

A modern inverter split system draws roughly 0.6 to 1 kW per hour of cooling at typical settings, so running it for six hours on a hot evening costs around £1 to £1.50 at current tariffs. Used as a heat pump in winter, the same unit is usually cheaper per unit of heat than a plug-in electric heater. The bigger long-term cost is neglecting it.

Plan for an annual service at £80 to £150. It keeps the filters and coil clean, checks refrigerant pressures and catches a failing capacitor or blocked drain before it becomes a callout in the middle of a heatwave. Most manufacturers also tie their warranty to evidence of yearly servicing, so it is worth keeping the paperwork.

Getting a quote that means something

Ask for a site survey rather than a price over the phone, and make sure the installer is F-Gas registered, since handling refrigerant without it is illegal in the UK. A good quote will itemise the unit model, pipe length included, any condensate pump, the electrical work and whether VAT is in or out. If one quote is far below the others, check what has been left off.

Late spring is the busiest time and lead times stretch, so if you want cooling by July, get surveys booked in March or April. Installers are often quieter from October to February, and that is when you are most likely to get a keener price and a quicker slot.