A mid terrace with no side access is a rear-wall job, or an alley job if that alley is real and you may use it. There is no side passage to pretend. The decision is whether the rear elevation or the alley can hold a lawful outdoor unit, and how the crew will carry it through the house. Survey that rear route, the drain and the neighbour on the other side of the fence. Pipe length and height still apply. An F-gas certified company installs the system after the spot is allowed.
There is no side of this house
Quotes copied from semis talk about the side of the house. A mid terrace does not have one, unless you are the end house, and this decision is about the house that is not. If a firm prices a side bracket, send them back. The outdoor unit goes on the rear wall, on a pad in the rear yard, or in an alley that exists behind or beside the yard. Party walls on both sides are not outdoor locations. Write that there is no side access. Photos of the rear elevation, the yard, the alley if one exists, and the path through the house from the front door, plus the indoor wall and the consumer unit, stop a drawing that shows a side passage.
The alley, the rear neighbour and the run to the front bedroom
An alley behind a terrace may be a public path, a private right of way, or a strip you own. Those are different permissions. A condenser opening into an alley can be lawful and practical, or it can block bins, gates and the neighbour's only access. Width has to take the unit plus airflow and a service panel. A slot that fails those gaps will recirculate and run loud. In England, check Planning Portal conditions for noise, size and use, aimed at the rear neighbour's windows as much as at the alley. A conservation terrace can need consent on the rear even when the front is the famous part. Flats in a terrace need the freeholder. Their passage next door, even if they are an end terrace, is not your route. Your outdoor unit stays on your rear wall, in your yard, or in an alley you are allowed to use.
Rear bedrooms and a rear kitchen are the short runs. A front bedroom means copper through the house or the loft, and that length plus the height from a two-storey terrace must stay inside the limit. If it does not, the front room is not on this outdoor unit. Cool the rear room you actually use, or accept two outdoor positions you do not have. Do not stretch the pipes past the datasheet. Condensate wants the rear gully. A pump is for a front room whose pipe cannot fall.
As a 2026 illustration, a rear single room on a mid terrace is often in the low thousands including VAT, close to a semi of the same size. The extra is access time and any alley permission, not a different kind of machine. Ask for the outdoor unit on the rear or in the alley only, with model codes, pipe length and how condensate reaches the rear drain. Ask them to confirm alley ownership if that is the spot.
Carrying the condenser through the hall
Carrying the condenser through the front door, the hall and the kitchen is normal. Say so, and protect the route. A unit that does not fit the stair is a smaller model or a different day with the right method, not a hole knocked through a party wall. Most domestic condensers fit if the stair and the turns are clear. Photograph the tightest corner. A survey that ignores the carry is how the unit stops in the hall.
Frequently asked questions
Can the installer use next door's side if they are an end terrace?
No. Their passage is not your route. Your outdoor unit stays on your rear wall, in your yard, or in an alley you are allowed to use.
Will the outdoor unit fit through the house?
Most domestic condensers do, if the stair and the turns are clear. Photograph the tightest corner. A survey that ignores the carry is how the unit stops in the hall.
Can I cool the front bedroom from the rear yard?
Only inside the pipe length and height limit for that model. If the run fails, choose a rear room or wait. Do not stretch the pipes past the datasheet.
Can a multi-split create a side of the house you do not have?
No. One outdoor spot that fails the alley, noise or boundary tests means you cool nothing until a different spot is found. A multi-split cannot create a second side of the house.
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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.