Do you need planning permission for a heat pump in London?

Key facts

• Air source heat pumps on houses and blocks of flats are permitted development in England, within limits.
• Since 29 May 2025: up to two units on a detached house, one on other houses and blocks of flats.
• The outdoor unit can be up to 1.5 cubic metres on a house and 0.6 cubic metres on a block of flats.
• The old rule that the unit had to be at least 1 metre from the boundary no longer applies.
• The installation must meet the noise standard named in the permitted development rules.
• Listed buildings and scheduled monuments have no permitted development rights for heat pumps.

What changed in 2025?

The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2025 came into force on 29 May 2025 and relaxed the rules for air source heat pumps. Detached houses can now have two units instead of one, the maximum size of the outdoor unit rose from 0.6 to 1.5 cubic metres for houses, and the rule that a unit had to be at least 1 metre from the property boundary was removed. The order also made clear that the right does not cover a heat pump used only for cooling.

The noise rule was tightened in a different way: the installation must meet the specific noise standard named in the rules, and the option of using an equivalent standard was removed. A transitional period for installations that relied on the old wording ended on 28 May 2026, so in November 2026 only the named standard applies.

What are the permitted development limits for a house?

• Number. One air source heat pump on a terraced or semi-detached house, two on a detached house. A wind turbine on the same property rules it out.
• Size. The outdoor compressor unit, including its housing, can be up to 1.5 cubic metres.
• Roof. Not on a pitched roof. On a flat roof, the unit must be at least 1 metre from the edge of the roof.
• Noise. The installation must meet the noise standard named in the rules, which calculates the sound level at the nearest neighbouring habitable room.
• Front walls. Outside conservation areas, a unit on a wall facing a road cannot be above ground-floor level.
• Siting. It should be sited, as far as practicable, to minimise its effect on the look of the building and on the amenity of the area, and removed when it is no longer needed.

What about conservation areas and listed buildings?

London has hundreds of conservation areas, so this matters. In a conservation area or a World Heritage Site, a heat pump is still permitted development, but not on a wall or roof that fronts a road, and not nearer to a road than the nearest part of the house. A unit in the back garden or on a rear wall is often fine; one on the front of the house needs planning permission.

Listed buildings and scheduled monuments have no permitted development rights for heat pumps. You will need planning permission and, for a listed building, listed building consent, so speak to your council's conservation officer early.

Can I install a heat pump in a flat?

A block of flats can have one air source heat pump as permitted development, with an outdoor unit of up to 0.6 cubic metres. In practice, a leaseholder will also need the freeholder's consent under the lease, and the outdoor space and the walls usually belong to the building, not to the individual flat. Check your lease and talk to the freeholder or managing agent before you plan anything.

Can my council remove these rights?

Yes. A council can remove permitted development rights in an area with an Article 4 direction, and an earlier planning permission may have removed them by condition. Each London borough decides its own directions, so check with the council for your address.

How can I be sure?

If you want written proof, apply to your council for a Lawful Development Certificate for the proposed installation. It confirms that the work shown on your plans would be lawful. Your installer should also give you the noise calculation for the chosen position.

Do I need building regulations approval?

A heat pump installation has to comply with the Building Regulations, for example for the electrical work and the efficiency of the new heating system. The Planning Portal advises using a suitably certified installer or a competent person scheme. If you are building an extension or a loft conversion at the same time, the heat pump can be planned into the same building control approval.

Frequently asked questions

Can I put a heat pump at the front of my house?

Outside conservation areas, yes, on the ground floor of a wall facing the road. In a conservation area, a unit on a wall or roof fronting the road needs planning permission.

How close to the boundary can a heat pump be?

Since 29 May 2025 there is no minimum distance from the boundary under permitted development, but the noise calculation still has to be met at the neighbour's nearest habitable room.

Do I need to tell my neighbours?

There is no legal requirement under permitted development, but it is good practice, especially if the unit will be close to their windows.

Is there a grant?

In England and Wales, the Boiler Upgrade Scheme takes £7,500 off an air source heat pump that replaces fossil fuel heating. See The Boiler Upgrade Scheme explained.

How can GONT LTD help?

GONT LTD is a London building company that builds house extensions and loft conversions and installs MVHR heat recovery ventilation. Our team holds F-Gas and NICEIC certifications, and we manage the whole process, from planning permission to building control sign-off. If you are weighing up a heat pump alongside building work, the consultation is free: call +44 7783 930505 (Monday to Friday, 9am to 5pm), email info@gont.co.uk, visit our showroom at 9 Royal Parade, Dawes Road, Fulham, or tell us about your project on our contact page. Our heat pump guide sums up the rules.

Sources

• Planning Portal: Air source heat pump, planning permission
• legislation.gov.uk: The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2025
• legislation.gov.uk: Class G, air source heat pumps on domestic premises
• Planning Portal: Heat pumps, building regulations
• GOV.UK: Planning permission

General guidance for homes in England, checked against the sources above on 10 November 2026. Your council has the final say on planning.