How expensive is air conditioning to install at home?

For a fixed, properly installed system, UK air conditioning in 2026 costs £1,500–£3,000 for a single-room split system — one indoor wall unit plus an outdoor condenser, and the most popular choice for a bedroom, home office or lounge. Cooling more rooms from one outdoor unit, a two-room multi-split runs £2,800–£4,500 and a three-to-four-room multi-split £3,500–£7,000. Whole-home ducted systems, with the kit hidden in ceilings or walls, are a bigger project at £6,000–£15,000.

Portable units are the cheap alternative at £200–£500 with no installation, but they are noisier and far less efficient than a fixed split system.

Two things to know before getting quotes. First, all fixed systems must be installed by an F-Gas registered engineer — it is a legal requirement because of the refrigerant involved, so always check registration. Second, location matters: London and the South East typically add 20–30% to installation prices.

Beyond that, price moves with capacity (a bigger room needs a bigger unit), how far the outdoor unit sits from the indoor one, and whether any electrical work is needed for a dedicated supply.

Our air conditioning cost guide breaks costs down by room, brand and running cost per summer. Ready for numbers for your own home? Compare three free quotes from F-Gas registered installers.