A loft conversion is the warmest room in the house, and in summer that is not a compliment. Heat rises, the roof takes direct sun all day, and the insulation that makes the room usable in January holds that heat in long after sunset. Most people find this out in their first July.
Air conditioning solves it properly. We install systems in converted lofts across London and Essex, both in rooms that are already finished and in conversions still being built.
Why loft rooms get so hot
Three things work against a loft at once. The roof is the part of the house exposed to the most sun, for the longest part of the day. The room sits at the top of the house, so warm air from every floor below collects there. And a converted loft is tightly insulated and reasonably airtight, which is exactly what you want in winter and exactly what traps heat in summer.
Opening the rooflight helps a little in the evening. It does nothing at three in the afternoon, when the air outside is warmer than the air inside, and it is not an option at all if the room is a bedroom at night or an office you need to be quiet.
What we install in a loft
Usually a single wall-mounted indoor unit sized for the room, paired with an outdoor unit. For most conversions that is the sensible answer. It is the least intrusive to install, the quickest, and the cheapest to run for one room.
Where the ceiling allows it, a ducted system is neater. The equipment sits out of sight above the plasterboard and the only thing visible in the room is a slim linear grille. We fitted one in a Woodford loft, and in that room there is no box on the wall at all.
Ducted needs a void to hide the equipment in, so it is a decision best made before the ceiling goes up. In a finished loft it is sometimes still possible and sometimes not. The survey tells us which.
Where the outdoor unit goes
It does not have to go on the roof. In most terraced and semi-detached houses it sits at ground level in the side return or the garden, with the pipework running up the outside of the building, or internally where there is a route for it.
Planning permission is not usually needed for a domestic outdoor unit, but there are conditions attached covering size, siting and noise, and they are stricter in a conservation area or on a listed building. We check that at survey rather than afterwards.
During the conversion, or after it
If the loft is still being built, this is the moment. Pipework and condensate drainage can be run inside the structure before it is closed up, the ducted option is genuinely open, and nobody has to lift finished flooring or chase a plastered wall. It costs less and it looks better.
If the conversion is already finished, that is perfectly normal too. Most of our loft installations are retrofits, the work is tidier than people expect, and a single room takes a day or two.
If the conversion itself has not started yet, our sister company Brick By Brick builds them, and the two trades talking to each other from the start saves a surprising amount of money and mess.
It heats the room as well
The same unit runs in reverse in winter, and a loft is often the room the central heating struggles to reach. It is a heat pump, so for every unit of electricity it uses it moves roughly three to four units of heat. That usually makes it cheaper to run up there than an electric heater, and it comes on in seconds rather than warming up a radiator.
Common questions
Will it be noisy at night?
A modern indoor unit on its lowest setting is quieter than a fridge. The outdoor unit is the one to think about, which is why where it goes matters, particularly in relation to your neighbour’s windows. We size and site it with that in mind.
Does it need a drain?
Yes. Cooling produces condensate, and it has to go somewhere sensible. In a loft that is usually a gravity run to an existing waste pipe, or a small pump where gravity will not do it.
Can one outdoor unit serve the loft and another room?
Often, yes. A multi-split system runs several indoor units from one outdoor unit, with separate controls in each room. It is worth asking about at survey even if the loft is the only room bothering you now, because adding to it later is much easier if the system was sized for it.
How long does it take?
A single room is usually one to two days from arrival to switch-on. We clear up as we go and take the packaging with us.
Do you work on lofts you did not build?
Yes, most of them. We do not need to have built the conversion to install into it.
Book a free survey
We survey free, explain what will actually work in your loft rather than what is easiest to sell, and quote a fixed price before any work starts.
Call 020 3488 4657, message us on WhatsApp, or use the contact page. You can also read how we work on our services page.