Air Conditioning for Listed Buildings

Listed homes can be hard to keep comfortable. Rooms under the roof and rooms with large windows can overheat in summer, and older buildings can be expensive to heat. Air conditioning is often possible, but it needs more planning than in an ordinary house, and you will usually need listed building consent before any work starts. Where nothing can be fitted to the outside, a water-cooled system can give you air conditioning with no outdoor unit at all.

Do You Need Listed Building Consent?

Usually, yes. In England, it is a criminal offence to carry out works that affect the character of a listed building, inside or out, without listed building consent. Air conditioning normally means fixing units to walls, making holes for pipework and running pipes and cables, so councils usually treat it as needing consent.

Permitted development rules for outdoor units do not cover listed buildings, so the outdoor unit may need planning permission as well. See our planning permission guide.

This applies to all grades: Grade I, Grade II* and Grade II. For Grade I and Grade II* buildings, the council also consults Historic England.

Start With the Council

1. Check the listing entry for your building on the National Heritage List for England.

2. Speak to your council's conservation officer early. Many councils offer pre-application advice.

3. Plan the system with your installer, including every unit position, pipe route and hole.

4. Apply for consent with drawings, photos and a heritage statement explaining the impact.

5. Wait for consent before any work starts.

We can provide the details your council will ask for, such as unit sizes, positions and pipe routes.

Choosing Discreet Indoor Units

• Floor-standing units can sit where a radiator would, avoiding fixings high on historic walls. See floor-standing air conditioning.

• Ducted units can go in a roof space or service void, with only small grilles in the rooms. They suit top-floor rooms with a usable loft. See ducted air conditioning.

• Wall-mounted units are the simplest, but they are the most visible. See wall-mounted air conditioning.

• Ceiling cassettes need a ceiling void and an opening cut into the ceiling, which can be harder to justify in a historic ceiling.

Water-Cooled Systems: No Outdoor Unit

A water-cooled system gets rid of the heat into water instead of the outside air. There is no outdoor unit and no need for large holes in the walls, just a cold water supply and a drain. Because they avoid changes to the outside of the building, water-cooled systems are often chosen for listed buildings.

There are two main types:

• All-in-one units mount on an inside wall and connect to a cold water supply and a drain. The compressor is in the room, so they are louder than a split system.

• Systems with an indoor condensing unit have a water-cooled condenser in a cupboard or utility space, which serves an indoor unit in the room. This keeps the noisiest part out of the room.

There are trade-offs to weigh up:

• Cost to buy. Water-cooled systems start from £5,000, which is considerably more than a standard split system.

• Cost to run. Mains-water units send water to the drain whenever they run, in heating as well as cooling. At full flow, some use several hundred litres of water an hour, which adds up quickly on a water meter.

• Plumbing. The unit needs a cold water supply and a drain nearby, and the plumbing has to meet the water fittings regulations.

• Consent. Listed building consent can cover work inside as well as outside, so the indoor units, pipework and plumbing still need agreeing with the council.

Our guide to air conditioning without an outdoor unit explains water-cooled systems and the other options in more detail.

If You Use an Outdoor Unit, Where Can It Go?

If an outdoor unit is acceptable, a standard split system is quieter and cheaper to run. Positions to discuss with the council include:

• away from the main elevations, such as at the rear or side of the building

• at ground level behind a wall, hedge or screen, rather than fixed to historic walls

• in a yard, an outbuilding or against a later extension, where fixings will not affect historic fabric

• on a flat roof hidden behind a parapet, where the council agrees

Pipework can often follow existing routes, such as old service holes, voids or later parts of the building, to avoid new holes through historic walls. See air conditioning trunking and pipework.

Protecting the Building

• Use fixings and routes that can be removed later with minimal damage.

• Keep condensate drains well away from historic surfaces, and make sure they cannot leak into walls.

• Check whether the work affects historic plaster, panelling or decoration, and plan around it.

Frequently Asked Questions

Is air conditioning allowed in listed buildings?

Often, yes, with listed building consent. The council will look at the impact on the building's character and how easily the work could be reversed.

What happens if I install it without consent?

Unauthorised works to a listed building are a criminal offence, and the council can require you to remove them and put right any damage.

Can I have air conditioning in a listed building without an outdoor unit?

Yes. A water-cooled system needs no outdoor unit, just a cold water supply and a drain. Water-cooled systems start from £5,000 and cost more to run than a standard split system, and the work inside still needs consent.

Do conservation areas have the same rules?

No, but conservation areas have their own limits, such as on outdoor units on walls facing a road. See our guide to air conditioning outdoor units.

Call 01772 288651 or use the form below to book a free survey. We will look at the building, talk you through the options, including water-cooled systems, and give you a clear written quote.

Last updated: November 2026.