Buyer's Guide 2026
Best air conditioning for a London flat, house or mansion block
A property-by-property guide to choosing the right AC in London. Written by F-Gas certified engineers who install split, ducted and water-cooled systems across the capital every week — with honest recommendations for leaseholders, homeowners and landlords.
Find your property type
The right AC in London depends less on brand and more on your building. Here's what we actually recommend for each scenario.
Leasehold flat in a mansion block
Kensington, Chelsea, Marylebone, Bayswater
Recommended: Water-cooled AC (Parkair MCW)
No outdoor unit means no façade impact, no planning consent and the fastest route to freeholder approval under a License to Alter.
See invisible ACListed building or conservation area
Notting Hill, Belgravia, Mayfair, Westminster
Recommended: Water-cooled AC (Parkair MCW)
External units are almost always refused. A concealed water/air heat pump keeps every element inside the flat and preserves the façade.
Leaseholder's guideModern flat or new-build with a balcony
Battersea, Nine Elms, Canary Wharf
Recommended: Split system AC (R32 inverter)
Where the freeholder already permits balcony-mounted units, a modern split from £1,495 is the fastest, cheapest and most efficient route.
See split ACBedroom-only cooling
Any London home
Recommended: Quiet-mode wall or floor unit
Whisper-quiet 19–22 dB operation and sleep-mode inverters cool a single room without disturbing rest — often the highest-value single install.
Bedroom ACLoft conversion or roof room
Victorian & Edwardian houses across London
Recommended: Ducted or split system with insulation review
Loft rooms overheat in July–August. A properly sized system paired with rafter insulation delivers year-round comfort where fans no longer cope.
Loft AC guideHouse with side return or garden
Fulham, Clapham, Islington, Hampstead
Recommended: Multi-split or ducted system
With space for a discreet outdoor unit, a multi-split covers 2–5 rooms from one condenser — great value per room, full heating in winter.
Home ACWhat actually matters when choosing AC in London
Planning & lease permission
In London, most flats need a License to Alter, and any visible external unit in a conservation area usually needs planning. Water-cooled systems side-step both — nothing goes outside.
Installation cost
Split AC starts at £1,495 for a single room. Multi-split for 2–3 rooms is £3,500–£6,000. Water-cooled multi-room systems run £4,000–£12,000, but usually avoid planning fees and long approval delays.
Noise & neighbours
Outdoor compressors run 40–55 dB — a common source of London complaints. Water-cooled AC eliminates that noise source entirely. Indoors, all modern systems run at 19–26 dB.
Building type & era
Period buildings, listed façades and mansion blocks almost always require concealed systems. New-builds and houses have more freedom to choose the cheaper split route.
Quick decision rules
Not sure which system suits your London property?
Book a free survey — we'll recommend the right AC for your building, budget and freeholder in plain English.