Air Conditioning · Updated August 2026
Split Air Conditioning Cost UK 2026
A single-room split system — one indoor head, one outdoor condenser — is the most common way to cool a UK home. Installed cost runs £1,500–£3,000 for a typical bedroom, home office or lounge, fitted in about a day.
Split air conditioning cost by capacity — 2026
Capacity is chosen from room size. Oversizing costs more up front and more to run.
| Capacity | BTU | Room size | Unit only | Labour | Installed total |
|---|---|---|---|---|---|
| 2.0kW | ~7,000 | Small box room / study (up to ~10 sq m) | £500–900 | £650–1,000 | £1,300–1,900 |
| 2.5kW | ~9,000 | Bedroom / home office (up to ~14 sq m) | £550–1,000 | £700–1,100 | £1,500–2,600 |
| 3.5kW | ~12,000 | Lounge / master bedroom (15–25 sq m) | £650–1,200 | £750–1,200 | £1,700–3,000 |
| 5.0kW | ~18,000 | Open-plan / large room (25–40 sq m) | £800–1,500 | £850–1,400 | £2,000–3,600 |
| 7.0kW | ~24,000 | Very large open-plan (40+ sq m) | £1,100–2,000 | £900–1,500 | £2,400–4,200 |
Source: Best Builders 2026 quote data across 519 UK towns.
What changes the cost
| Cost factor | Typical impact | Why it matters |
|---|---|---|
| Pipe run length | +£150–400 | Runs over ~5m need extra refrigerant pipe, insulation and labour; long vertical runs in flats cost most |
| Condenser siting & access | +£100–600 | Ground level next to the room is cheapest; roof, height or scaffold access adds cost |
| Number of indoor units | +£700–1,500 each | Each extra head adds unit, pipework and commissioning time |
| Electrical work | +£150–500 | A dedicated spur, consumer-unit way or isolator may be needed |
| Capacity (kW / BTU) | +£200–1,200 | Oversizing wastes money up front and on running cost |
| Brand & range | +£400–800 | Premium Daikin/Mitsubishi designer ranges vs value Samsung/LG |
| Making good | +£0–300 | Trunking, core-drilling, plaster patching or repainting around the route |
Air conditioning cost by UK region — 2026
Labour rates and access drive most of the regional spread. Figures below are for a single-room split; the same percentages apply across the other system types.
| Region | Single-room split (installed) | vs UK average |
|---|---|---|
| London | £1,900–3,600 | +25–30% |
| South East | £1,750–3,300 | +15–25% |
| South West & East | £1,550–3,000 | +5–10% |
| Midlands | £1,450–2,800 | Baseline |
| North of England | £1,400–2,700 | −5% |
| Wales & Scotland | £1,400–2,750 | −5% to baseline |
Getting it priced properly
1. Size it first
Capacity comes from room size, glazing and aspect — not from guesswork. An installer who quotes without asking about the room is guessing.
2. Check F-Gas registration
Anything touching the refrigerant circuit legally requires an F-Gas registered engineer. Ask to see it and check it on the register.
3. Compare like for like
Get three itemised quotes covering the same capacity, brand tier and pipe run, so you are comparing the job and not the wording.
Single-room split — frequently asked questions
One indoor head and one condenser is a one-day job for a two-person team, assuming the condenser sits at ground level near the room and the pipe run is under about 5m.
Yes. Every modern split is a reversible heat pump, so it heats in winter as well as cools in summer, typically at a SCOP of 4.0–5.1 depending on brand and model.
Usually not for a single external unit on a house within permitted development, but siting, noise and conservation-area status all matter. Check the planning permission guide before you commit.
A 2.5kW bedroom split draws 0.3–0.7kW cooling, which is roughly 7–20p an hour, or £30–70 across a UK summer.
Related air conditioning guides
Every system type priced side by side.
What it costs per hour and per summer.
When an external unit needs consent.
Reviewed by the BestBuilders editorial team on 9 August 2026 · Next scheduled review: November 2026 · See our editorial standards.