Who it suits
- Rear and side-return extensions
- Kitchen-diners with roof lanterns
- Rooms with bifold or sliding doors
- Open-plan ground floors
Why are extensions so hard to cool?
Roof lanterns and glazed doors let in a lot of sun, flat roofs heat up during the day, and ovens and hobs add their own heat. The space can also be long and narrow. We size from the glazing area, the roof and the layout, and if one unit cannot throw air evenly to both ends we recommend two.
When is the best time to plan it?
During the build, before plastering, so pipes and cables can be hidden in the walls or roof void. It can still be added later with a neat surface route, usually on the side wall of the extension.
What about the kitchen?
Indoor units should not sit directly above hobs or ovens, where grease and heat build up. We place them where they can reach the cooking area without being in the line of steam and fumes, and they work alongside your cooker hood, not instead of it.
What is included
- Free survey with glazing and roof heat-gain check
- One or two units sized for the whole space
- Placement clear of the hob and oven
- Hidden routes during the build, or neat surface routes after
- Pressure test, vacuum and commissioning
- Handover of the remote or app
Air conditioning for extensions and kitchen-diners prices
Guide prices for air conditioning for extensions and kitchen-diners run from £1,450 to £4,450 per space, including VAT, depending on the options below. Higher-capacity wall unit, or two units, for a large open-plan space with glazing. The survey turns this into a fixed written price.
Single unit
One 3.5–5 kW unit for a medium extension.
Large single
One 5–7 kW unit for a large glazed space.
Twin units
Two indoor units on a multi-split for long or L-shaped spaces.
Guide prices show VAT at 20%. HMRC treats most fixed air conditioners and air-to-air heat pumps installed in homes as energy-saving materials, zero-rated until 31 March 2027 when we supply and fit them. If your installation qualifies, your quote shows 0% VAT and a lower price. Servicing, repairs, cleaning and controls are charged at 20%.
UK middle prices. London and the South East are typically higher and much of the North, Scotland and Wales a little lower; see your area page for a local figure.