Can I get a heat pump in a flat or leasehold property?

Heat pumps in flats are technically possible but practically difficult. The two blockers are space for the outdoor unit and getting freeholder consent. Around 70% of UK flats can be retrofitted given the right circumstances; 30% are blocked by lease terms or building constraints.

What you can install

• Air-to-air mini-split: like a Japanese-style aircon. Cools and heats. One outdoor unit per indoor unit. Around £2,500-£4,500 per room. Quick install (1 day). Does NOT qualify for the Boiler Upgrade Scheme.
• Air-to-water heat pump: the standard whole-house heat pump that runs hot water + radiators. £8,000-£14,000 install. £7,500 BUS grant available. Requires space for a hot water cylinder and outdoor unit.
• Communal heat pump: a shared system serving all flats, installed by the building owner. Increasingly common in new-build apartment blocks. Almost never retrofitted into existing buildings.

For flat owners, the realistic options are an air-to-air mini-split (no grant but easier install) or — if you have a balcony / dedicated wall space and freeholder consent — an air-to-water system with the £7,500 grant.

The freeholder problem

Almost every leasehold flat needs freeholder consent for an outdoor unit attached to the external wall. Most leases include "alterations" clauses requiring written permission. The freeholder cannot unreasonably withhold consent — but they can charge consent fees (£200-£500), require a legal survey (£300-£800), and impose ongoing maintenance obligations.

Realistic timeline: 8-16 weeks from application to consent for cooperative freeholders, longer for absentee or institutional freeholders. Budget £500-£1,500 in consent fees and legal costs.

Where the outdoor unit can go

• Balcony: works for ground- and lower-floor flats. Avoid bedroom windows above. Anti-vibration mounts essential.
• External wall bracket: small unit suspended from the wall. Common for upper flats. Requires structural assessment.
• Roof / communal area: requires the building manager to approve and is rarely allowed for individual leaseholders.
• Garden (ground floor): easy, treat as a normal house install.

Ducted units (where the outdoor unit serves multiple indoor units inside one flat) are increasingly available and reduce the visual impact.

The hot water cylinder problem

Air-to-water heat pumps need a hot water cylinder — typically 200-300 litres for a 2-bed flat. That is roughly the footprint of a tall wardrobe. Most flats with combi boilers have no cylinder space. Options:

• Convert an airing cupboard or storage cupboard.
• Use a slim-profile or stacked cylinder (1m × 1m × 2m).
• Stick with combi-style instant hot water — incompatible with most heat pumps, but a few hybrid systems (Vaillant aroTHERM Plus + flow boiler) can work.

Will the BUS grant pay out?

Yes, for leasehold flats — the grant is available to the property "owner of record" which includes leaseholders. You need:

• Freeholder consent in writing (don't skip this — Ofgem will ask).
• An EPC for your individual flat (not the whole building).
• The standard insulation prerequisites met (loft insulation rarely applies to flats; cavity wall does if your flat has external cavity walls).
• An MCS-certified installer who has experience with flat installs.

What about communal heating systems?

If your building has a communal boiler / district heating, you cannot install your own heat pump — your contribution to heating is paid via service charges. Pressure your management company to switch the communal system to a heat pump (becoming more common, but slow).

The cost reality

For a 2-bed flat where everything works:

• Air-to-water heat pump: £8,500 install − £7,500 BUS = £1,000 net.
• Plus freeholder consent + legal: £500-£1,500.
• Plus cylinder cupboard conversion (if needed): £500-£2,000.
• Realistic all-in: £2,000-£4,500.

Compared to a £1,500-£2,500 boiler replacement, the maths still works given the 5-7 year payback on running costs.

The bottom line

Possible in most flats; smooth in well-managed buildings with cooperative freeholders; impossible if your lease is restrictive or your building is communal-heated. Always start with the lease and the freeholder before getting installer quotes. Run our free pre-survey check to see what the install would look like on your specific property — it works on flats too.