Cooling three bedrooms, and leaving the living room and the rest of the house without air conditioning, is still a multi-room job. A 2026 illustration for three indoor units on one outdoor unit, with workable access and drains that fall, often sits around the mid thousands of pounds including VAT, and moves up with pumps, pipe length, a second outdoor unit or London access. Three separate outdoor units can cost more in labour and in noise. This is an illustration, not a price list.
Three shut bedroom doors
Each closed bedroom needs its own indoor unit. A single head on the landing does not cool three shut doors. The living room can stay off the job if you say so.
One condenser if the pipes can reach
A multi-split with three indoors and one outdoor unit is the usual tidy layout, if the pipes can reach and the outdoor unit can carry a hot night when all three run.
- Three closed bedrooms need three indoor units.
- One outdoor unit is the usual first design.
- Pipe limits can force a second condenser.
- The living room can stay off if you say so.
Three outdoor units beside bedroom windows
Three single splits are three condensers on the walls. That can be right on a long house where one plant position cannot see every bedroom inside the pipe limit. It is also three noise sources beside bedroom windows. The survey should price both if the geometry is awkward.
Scaffold, a pump and a board with no spare way
Short pipe runs and gravity drains keep a three-bedroom job nearer the straightforward band. First-floor bedrooms over a hall, a pump to a distant stack, trunking you want hidden, and a consumer unit with no spare way each add cost. Scaffold for a high outdoor unit is its own line. London access, a terrace with no side passage, and a lease on a flat sit outside a simple house band. Compare prices only when all three name the same three rooms, the same outdoor spot and the same drain. Three bedrooms are usually cheaper than a whole-house system, because you are buying fewer indoor units and a smaller outdoor combination. Access, pumps and London conditions can still lift it into the same band as a larger easy house.
Night running and the wall by the bed
Bedrooms run in the evening and sometimes overnight. That is electrical units at the rate on your bill, for the hours you choose. A modest setpoint and a timer limit that. Energy Saving Trust frames reversible units as air-to-air heat pumps if you also want heat on cold nights. Put the outdoor unit away from the head of the bed on the other side of the wall. Anti-vibration mounts matter more than a smaller kilowatt badge. In England, check Planning Portal conditions for the outdoor position.
A living room added later, or a head on the landing
Leaving the living room out is the wrong plan when you already know you want it cooled, because the outdoor unit chosen for three bedrooms may have no spare port or no spare capacity for a fourth indoor. Say so at the survey. A head on the landing is the wrong plan for the same three shut doors.
Core buying guides
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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.