Can I install air conditioning in a terraced house?

Yes. Most terraced houses can have air conditioning, and in England it is usually permitted development, so there is no planning application. The outdoor unit normally goes on the back wall, in the rear yard or on a flat extension roof. Permitted development allows one outdoor unit on a terrace, so several rooms share it through a multi split.

Do I need my neighbour's permission to fit air conditioning?

Not for planning. Permitted development does not need their consent, and they are protected by the noise limit, which is measured at their window. If anything would be fixed to their side of a shared wall or pass over their land, you would need their agreement, which is one more reason to keep the whole installation on your own back wall.

Can the outdoor unit go on the front of a terraced house?

Rarely. Permitted development excludes a wall above ground floor level that faces a road, and in a conservation area the unit cannot sit nearer the road than the house itself. A ground level position at the front can be allowed outside a conservation area, but on most terraces the front door opens onto the pavement, so the back is the practical answer.

What if the terrace has been converted into flats?

Then the rules for flats apply instead. Planning limits are tighter, and the lease almost certainly needs the freeholder or managing agent to approve anything fixed to the outside of the building. That consent is separate from planning and catches more people out.

How long does it take to install in a terraced house?

A single room is usually one day. A multi split serving several rooms normally takes one to two days, depending on how far the pipework has to travel from the back of the house to the front rooms.

Air conditioning in a terraced house

Terraced houses are among the most common homes in the North West, and the answer for them is nearly always yes. The questions that decide how it is done are where the outdoor unit can go, how the pipework reaches the rooms, and how many rooms you want to cool, because a terraced house is allowed one outdoor unit.

Where does the outdoor unit go on a terraced house?

Almost always at the back. There are three usual positions:

On the back wall at ground level, on a wall bracket or a small stand
In the rear yard, on a ground stand, which the removal of the old one metre boundary rule has made possible in far more small yards than before
On the flat roof of a rear extension, at least a metre from the edge

The front is usually ruled out. Permitted development excludes a wall above ground floor level that faces a road, and in a conservation area the unit cannot sit nearer the road than any part of the house.

One position to avoid even where it is allowed is the party wall. A condenser fixed to a shared wall passes vibration straight into the house next door, and it puts the unit as close as it can get to your neighbour's windows.

Do I need planning permission?

Usually not, in England. Since 29 May 2025 an outdoor unit on a house is permitted development if it is no bigger than 1.5 cubic metres, meets the 42 dB(A) noise limit at the neighbour's window, is not used for cooling alone, and is not on a pitched roof. On a house that is not detached, that covers one outdoor unit.

The exceptions are listed buildings, which need listed building consent, and conservation areas, which push the unit to the rear. The full planning rules set out every condition. Scotland, Wales and Northern Ireland have their own rules.

What if I want to cool more than one room?

Because a terrace is allowed one outdoor unit, several rooms are done with a multi split: one outdoor unit serving two to five indoor units, with each room on its own controller. A bedroom can run cooler overnight while the lounge is off.

A multi split outdoor unit is larger than a single one but still comfortably inside the 1.5 cubic metre limit. It also needs a bigger electrical circuit, which we check at survey.

How do the pipes get from the back yard to a front bedroom?

This is the real challenge in a terrace. The house is long and narrow, and the front rooms are as far from the only outside space as it is possible to be.

The pipework usually travels through the loft, under the floorboards, or boxed in neatly along a wall. Most domestic units are designed for runs of 15 metres or more, so distance is rarely the barrier, but it affects price: an installed price includes up to five metres of pipe run, and a longer route adds labour and materials. Each indoor unit also needs somewhere for its condensate to drain, either by gravity to the outside or through a small pump.

The survey plans that route before anything is quoted, so the price you get already includes it.

Will the neighbours hear it?

They should not, and the noise limit exists to make sure of it. The 42 dB(A) figure is measured at the nearest window of a room they live in, not at the unit. A typical domestic condenser produces somewhere in the high 40s to low 50s at one metre, and the level falls quickly with distance and with a wall or fence in between.

Position does most of the work, along with anti vibration mounts and the quiet night modes most units have. We work out the noise at the neighbour's window for the proposed position at survey.

Does a terraced house need a smaller unit?

Often, yes. A mid terrace shares both side walls with homes that are heated and cooled too, so far less heat passes through those walls than through an outside wall. The same room in a mid terrace frequently needs a smaller unit than it would in a detached house. An end terrace behaves more like a semi.

The size calculator gives you a starting figure, and the survey confirms it.

What does it cost?

A single room starts at £1,850 fitted and a multi split for two to five rooms at £3,450 installed, with no VAT to add until 31 March 2027. Long pipe routes from the back of the house to the front are the most common reason a terrace comes in above those figures. The domestic price list has the rest.