What a properly-installed split AC actually costs in 2026.
Primary question · What should I budget for a single-room AC install; and what drives the variance?
A single 2.5 kW wall-mounted split, installed by an F-Gas engineer, is typically £1,600–£3,400 in 2026. The spread is driven by brand tier, pipe route complexity, scaffolding for upper floors, and whether existing electrical capacity is sufficient. Multi-splits scale on total output, not room count.
Anyone planning a real installed cost, not an Amazon-box-only number.
Single split: £1,600–£3,400. Multi-split serving 2 rooms: £3,500–£5,500. Multi-split serving 3+: £5,500–£8,500.
- Real installed numbers, not list prices
- Honest about the cost variance drivers
- Won't include genuinely difficult installs (listed, high-rise)
Use the AC cost planner to put a number on your specific home.
The cheapest properly-installed split is around £1,600. Anything below that on the internet is either kit-only or a corner-cutting installer. Both will cost you more later.