New homes are well insulated and airtight, which keeps heat in during winter and can also keep it in during summer. Overheating in new homes is now dealt with in the Building Regulations, and more buyers are asking about cooling.
This guide is in two parts. For developers and self-builders, it covers the overheating rules, planning and the first-fix provision that makes a later installation simple. For buyers, it covers what to ask before you buy and what to check before drilling into a new home.
Overheating and the Building Regulations
Approved Document O deals with overheating mitigation in new residential buildings in England. It’s the designer’s job to show how the home meets it, and the approach usually starts with glazing, shading and ventilation. If you’re planning a new home, ask your designer how Part O is being met before deciding whether mechanical cooling is needed, and where it would go if it is.
New homes often have MVHR too. Air conditioning and MVHR do different jobs and work well together; see ventilation and MVHR.
Developers: plan it at design stage
Outdoor unit positions affect elevations, gardens and neighbours. Deciding them at design stage means they can be shown on the planning drawings and fitted where they look right. Heat pump outdoor units on houses can be permitted development under the Planning Portal’s conditions, but on a new development, permitted development rights are sometimes restricted by planning conditions. Check the consent.
First-fix provision that pays off
- Pipe routes. Sleeves through external walls at the planned indoor unit positions, and capped routes in walls or voids so pipework doesn’t need trunking later.
- Condensate. A drain connection near each indoor unit position, with a trap, falling to the waste system.
- Power. A circuit or spare way in the consumer unit for the outdoor unit, with the isolator position agreed.
- Fixings. Pattressing in stud walls where indoor units will hang, and bases or bracket positions for outdoor units.
- Records. Drawings showing where everything is, for the buyer and the installer.
We can advise on provision for your plans and give you a fixed-price quote for the full installation or the first fix alone.
Want it done properly? AirCon Doctor installs, repairs and services air conditioning and heat pumps across London and the South East, from our base in East Grinstead. We’re an F-Gas certified company and NICEIC approved. Get a fixed-price quote.
Developers: larger schemes
Apartment blocks need a strategy for outdoor units: balconies, a roof plant area or a central system. Large or mixed-use buildings may suit VRF. Remember that the flat-specific planning limits apply, fire stopping is needed wherever pipework passes through compartment walls and floors, and systems over 12 kW will later need TM44 inspections.
Buyers: ask before you buy
If you’re buying off-plan, ask the developer whether cooling or provision can be added, and get any agreement in writing. Ask for the drawings showing pipe sleeves, circuits and drain points if they exist. For flats, check what the lease and the building rules say about outdoor units; see leasehold consent.
Buyers: before drilling a new home
Check your new home warranty and any developer guarantee for conditions about alterations, especially holes through external walls and the airtightness layer. Check the planning consent for restrictions. Then we can survey and plan an installation that keeps holes to a minimum and seals them properly. In a well-insulated home, the cooling load is often lower than in an older house, which can mean smaller units.
What it costs
For a retrofit, a single room split system costs £1,200–£2,200 + VAT, a 2-room multi-split £2,800–£4,500 + VAT and a 3–5 room multi-split £4,500–£8,500 + VAT. Developer packages and first-fix provision are priced after we’ve seen the drawings. See our guide to what a quote should include.
Quick answers
Do new build homes need air conditioning?
Not by law. Approved Document O requires new homes to deal with overheating, usually through design first. Cooling is a choice many buyers then make.
What provision should a developer include?
Pipe sleeves and routes, condensate drain points, a power supply, fixings for the indoor units and bases or brackets for the outdoor units, all shown on drawings.
Can I fit air conditioning to my new build straight away?
Usually, but check your new home warranty, the planning consent and, for flats, your lease first.
Does air conditioning work with MVHR?
Yes. MVHR provides fresh air; air conditioning cools and heats the room air. They complement each other.
Related services
- Air conditioning installation
- Domestic air conditioning
- Multi-split air conditioning
- Ventilation systems and MVHR
More advice
- Air Conditioning for Apartments and Flats: Complete Guide
- Air Conditioning in a Leasehold Flat: Getting Consent
- Air Conditioning Installation Cost: What the Quote Should Include
- Do I Need Planning Permission for Air Conditioning in the UK?
- All advice
This guide is general information, checked against the sources linked on 30 October 2026. It isn’t legal, tax or financial advice. Rules, grants and product ranges change, so check the current position before you rely on it.