A single wall mounted split is the cheapest fixed air conditioning in the UK. As a July 2026 illustration, straightforward single room installations with a short pipe run commonly land in the high hundreds to low thousands of pounds including equipment, labour and VAT, with premium brands, long pipe runs, condensate pumps and London access pushing towards the mid thousands. Each additional room on a multi split adds an indoor unit and labour rather than a whole new system. The pipe route between indoor and outdoor unit is the single biggest variable, so compare quotes on the same route or you are comparing different jobs.
What the money buys
A wall split installation includes the indoor unit, outdoor condenser, refrigerant pipework in trunking or chased in, condensate drainage, a dedicated electrical supply with protection, vacuum and pressure testing, commissioning and F-gas paperwork.
The back-to-back installation, indoor unit on the inside of the wall where the outdoor unit hangs, is the benchmark cheap job: three metres of pipe, gravity drain, one wall penetration. Every metre and corner away from that adds labour.
- Back-to-back single room: the entry price for fixed cooling.
- Long internal pipe runs and external ladder work add hours.
- A condensate pump appears whenever gravity drainage is impossible.
- Electrical distance from the consumer unit is a quiet price driver.
- Scaffolding or tower access can add more than the indoor unit costs.
Illustrative bands for 2026
Single room, easy route, mid-range brand: high hundreds to around two thousand pounds installed. Single room with awkward access, premium equipment or heating-optimised units: two to three thousand. Two rooms on a multi split: commonly three to five thousand. Four or five rooms: usually five figures come into view once the larger outdoor unit and controls are counted.
These are planning shapes, not quotes. The three bedroom house cost guide and the full installation cost guide show how the bands build from labour rates and equipment tiers.
Why two quotes for one room differ by a thousand pounds
Different assumed pipe routes, different electrical scope, one price including making good and one not, and different equipment tiers under the same brand name. A quote that does not state pipe length assumptions, drain method and electrical works is not comparable with one that does.
Ask both companies to price the same written route. The questions to ask an installer guide gives the exact wording.
Getting firm prices
Photograph the room wall, the outside wall and the fuse board, state the room size and whether you want heating in winter, and share the postcode for access assessment. That is enough for most companies to give a tight range before a survey.
Use the quote form and interested local installers come back with route-based prices. No lead selling, no marked-up national call centre.
Frequently asked questions
How much does a wall mounted air conditioner cost installed in the UK?
As a 2026 illustration, straightforward single room wall splits commonly land between the high hundreds and low thousands of pounds installed, with premium brands and difficult pipe routes pushing higher. Additional rooms on a multi split add per-room cost rather than doubling the system.
Why is the pipe run such a big deal?
Labour follows the route. Every extra metre of refrigerant pipe, every corner, trunking run, wall chase and ladder position adds time, and long runs can also need larger pipe and extra refrigerant. Back-to-back routes are cheap because none of that applies.
Does the price include electrical work?
It should include a dedicated supply and protective device by a competent person, but scope varies. Confirm whether consumer unit work, long cable runs or certification are inside the price, because an excluded electrical day is a common source of surprise invoices.
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.