Heat pumps for landlords in Cambridge

Cambridge’s rented homes: a city of flats

Cambridge has 16,495 privately rented households out of 52,474, which is 31.4% (2021 Census). Owner-occupiers are 44.1% and social tenants 22.7%.

The figure that stands out is flats. Purpose-built flats are 30.7% of households, about 16,100 households, which is the largest single property type in the city. Terraced homes are 27.6% (about 14,500), semis 26.4%, detached 10.9% and converted houses 3.1%. Compare Nottingham, where flats are 18.4%: a Cambridge landlord is much more likely to be weighing a heat pump for a flat.

That changes the question. In a terrace or semi the issue is usually space and noise. In a purpose-built flat it is consent, the size of the unit allowed and whether the building has anywhere to put it.

These shares cover all households, not only rented ones, so check your own property.

How Cambridge heats its homes

Mains gas heats 75.1% of Cambridge homes, about 39,400 households. Electric-only heating is 11.6%, about 6,100. District heating is 2.1%, about 1,100, oil 0.2%, and 1.6% have no central heating.

With oil at 0.2%, the £9,000 off-gas Boiler Upgrade Scheme rate, which needs oil or LPG and no mains gas connection, will rarely apply inside the city. Plan on £7,500. The electric-only homes are where a heat pump has the clearest running-cost case, because a heat pump at SCOP 3.0 uses about a third of the electricity of direct electric heating.

Worked example (modelled, not a real project)

Inputs: a three-bedroom terraced house using 10,000kWh of heat a year (an assumption), a gas boiler at 90% efficiency, a heat pump at SCOP 3.0 or 3.5, and Ofgem cap unit rates for 1 October to 31 December 2026: electricity 26.32p and gas 7.97p per kWh. Standing charges are left out.

Heating	Fuel needed	Fuel cost a year
Gas boiler, 90%	11,111kWh gas	about £886
Heat pump, SCOP 3.0	3,333kWh electricity	about £877
Heat pump, SCOP 3.5	2,857kWh electricity	about £752

At SCOP 3.0 the running cost is roughly level with gas. At 3.5 the tenant saves about £130 a year. The Energy Saving Trust puts a typical air source heat pump at around £12,000 before grant, so about £4,500 after the £7,500 grant, before radiators, a hot water cylinder or insulation. Use the landlord heat pump calculator with your own figures.

Flats: what the planning rules allow

Because so many Cambridge rentals are flats, the permitted development limits matter more here than in most cities.

Rule (England, air source)	House	Block of flats
Maximum compressor unit size	1.5 cubic metres	0.6 cubic metres
Number of units	1 if not detached, 2 if detached	1
Noise limit	37.0 dB(A)	37.0 dB(A)
Pitched roof	Not allowed	Not allowed

A leaseholder landlord usually also needs the freeholder’s or management company’s consent before fixing anything to the outside of the building. For a small electric-heated flat, an air-to-air heat pump funded at £2,500 where it replaces existing heating can be the practical route. Read heat pumps for flats before spending anything.

Terraces and semis: the easier half

Terraces (27.6%) and semis (26.4%) together make up more than half of Cambridge households, and they are usually the simpler heat pump candidates. There is normally a rear garden or yard for the outdoor unit and space for a hot water cylinder. Two limits matter. Only one unit is allowed under permitted development on a house that is not detached, and with detached homes at just 10.9% that covers most Cambridge rentals. And the 37.0 dB(A) noise limit is measured against the neighbour, which is harder to meet in a narrow terrace yard. Measure the position before asking for quotes.

Licensing in Cambridge

Cambridge is lighter on licensing than Oxford or Bristol. The council’s HMO licensing page sets out the national mandatory licence: an HMO occupied by five or more people forming two or more households, or a purpose-built flat in a block of up to two flats occupied as an HMO by five or more people. For applications due from 1 April 2026 to 31 March 2027 the fee is £1,133. An HMO with seven or more tenants also needs planning and building control permission.

The council commissioned a feasibility study into selective licensing in March 2020. It found that introducing selective licensing was not appropriate, and the council agreed actions on the private rented sector in May 2021. There is no HMO Article 4 direction for Cambridge on the national planning data register; its recorded Article 4 directions cover the Accordia estate and a list of public houses. Even so, check the council’s current position before converting or letting.

Conservation areas and heritage

The national planning data register lists 18 conservation areas for Cambridge, including the Historic Core, Mill Road, New Town and Glisson Road, Kite, Castle and Victoria Road, De Freville and Chesterton.

In a conservation area, an air source unit is not permitted development if it is on a wall or roof that fronts a highway, or if it would be nearer the road than the house. Listed buildings are outside air source permitted development entirely. So for a terrace in Mill Road or New Town, a rear-garden or rear-yard position is usually the only route without a planning application.

Grants and funding in Cambridge

• Boiler Upgrade Scheme: £7,500 for air-to-water or ground source; landlords are eligible. See the BUS page for landlords.
• Warm Homes: Local Grant: GOV.UK lists Cambridge as lead authority with £8,805,153 for a partnership with East Cambridgeshire, South Cambridgeshire, Fenland, Huntingdonshire and Peterborough. The council says upgrades could include insulation, solar panels or an air source heat pump for low-income homes. Read the Warm Homes Local Grant page for landlord terms, including the no-rent-rise declaration.
• Action on Energy: the council’s grant partnership, which it says is available to homeowners and private landlords for low-income households.
• Warm Homes Loan Scheme: a lender loan, not a grant.

The council’s climate plan and heat network

On 24 March 2026 the council’s Cabinet approved a Climate Change Strategy for 2026 to 2031, aiming for net zero in the council’s own operations by 2030 and supporting the city to do the same. It also approved £600,000 to progress a City Centre Heat Network: air and river source heat pumps serving heritage buildings including the Guildhall, the Corn Exchange and Parkside Pools. It is a council project, not a rule for landlords, and not one most rentals could connect to. Cambridge is not on the government’s Heat Network Zoning Pilot list.

Your legal duties come from the EPC rules: EPC E today, and EPC C by 1 October 2030 as planned policy with a £10,000 cost cap, regulations not yet laid. See EPC C 2030 and your heating choice.

When a heat pump is the wrong answer in Cambridge

• A purpose-built flat where the freeholder will not consent or there is no compliant position.
• A street-facing position in a conservation area or a listed building.
• A gas-heated terrace with poor insulation, where tenants would pay more unless SCOP is high.
• A property you plan to sell soon.

To test a specific property, use the calculator above or send an enquiry. Relevant independent firms contact you, with no charge to you and no obligation.