Air conditioning for extensions and kitchen-diners in Carterton
An extension in Carterton with a roof lantern or large glazed doors can overheat quickly on a sunny afternoon. The South East sees some of the UK's warmest summer days, and south-facing rooms and conservatories feel it first.
In Carterton, a side wall of a single-storey extension is usually the neatest place for the indoor unit. Carterton sits around 14 miles from Oxford, inside our Oxfordshire area. That includes the OX18 postcode district.
Prices in Carterton
Budget around £1,745–£5,445 per space including VAT for air conditioning for extensions and kitchen-diners in and around Carterton. That is above the UK middle, mainly because labour and access cost more in South East England. Longer or hidden pipe runs, high-level brackets and electrical upgrades are the usual reasons a quote lands at the top of the range. Typical Large single work (one 5–7 kW unit for a large glazed space) lands around £2,495–£3,495 in this area.
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%.
Planning and permissions
Since 29 May 2025, England's permitted development rules allow larger outdoor units (up to 1.5 m³) and no longer require a 1 m gap to the boundary, provided the MCS 020(a) noise check is met. Listed buildings and pitched-roof installs still need permission.
The survey
The free survey is where the real price is set: room measurements, pipe and drain routes, electrical checks and the outdoor unit position, all written into your quote. On a survey in Carterton the engineer looks at room size, glazing, the route for pipes and drains, the electrics and where the outdoor unit can sit quietly, then the written quote follows.
What is included
What a job in Carterton covers:
- Pressure test, vacuum and commissioning
- One or two units sized for the whole space
- Placement clear of the hob and oven
- Free survey with glazing and roof heat-gain check
- Hidden routes during the build, or neat surface routes after
Nearby
We also cover Witney (5 miles), Wantage (14 miles) and Oxford (14 miles). See all services in Carterton or air conditioning for extensions and kitchen-diners across Oxfordshire.