Heat pumps for landlords in Southampton

Southampton is a flats and electric heating city

Southampton has 29,860 privately rented households out of 102,290, which is 29.2% (2021 Census). Owner-occupiers are 47.7% and social tenants 21.9%.

Two figures set Southampton apart from the other cities in this guide:

• Flats are the largest property type. Purpose-built flats are 34.7% of households, about 35,500 households, and converted houses add another 5.1%, about 5,200. Terraced homes are only 19.6% (about 20,000), semis 25.8% and detached 13.0%.
• Gas is lower and electric is higher. Mains gas heats 66.2% of homes, about 67,700. Electric-only heating is 21.0%, about 21,500 households, nearly double the 11.0% in Nottingham and Leicester. District heating is 1.5%, oil 0.1%, and 2.2% have no central heating.

For a landlord that combination means the classic gas-to-heat-pump question is less dominant here. The more common Southampton question is: what do I do with an electric-heated flat?

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

Worked example (modelled, not a real project)

Inputs: a one or two-bedroom flat with direct electric heating (panel or storage heaters treated as 100% efficient), using 5,000kWh of heat a year (an assumption; the site’s fact sheet uses 12,000kWh for a three-bedroom semi), a heat pump at SCOP 3.0 or 3.5, and the Ofgem cap electricity unit rate of 26.32p per kWh for 1 October to 31 December 2026. Standing charges are left out, and off-peak storage heater tariffs would narrow the gap.

Heating	Electricity needed	Cost a year
Direct electric, 100%	5,000kWh	about £1,316
Heat pump, SCOP 3.0	1,667kWh	about £439
Heat pump, SCOP 3.5	1,429kWh	about £376

That is a saving of roughly £880 to £940 a year for whoever pays the bill, usually the tenant. Against gas, the same flat would see little or no saving at today’s prices, because gas is 7.97p per kWh. This is why the electric-heated part of Southampton’s rental stock is where a heat pump earns its place.

The catch is installation. A wet air-to-water system needs radiators and usually a hot water cylinder, which a small flat may not have room for. An air-to-air heat pump, funded at £2,500 where it replaces existing heating, can be the practical option. Compare it against modern storage heaters before deciding.

Gas-heated houses: a closer call

The 66.2% of Southampton homes on mains gas face the same sums as anywhere else. Using this site’s illustrative three-bedroom semi at 12,000kWh of heat a year, a 90% gas boiler costs about £1,063 a year at the October 2026 cap, a heat pump at SCOP 3.0 about £1,053, and at SCOP 3.5 about £902. So for the 25.8% of homes that are semis and 19.6% that are terraces, a heat pump is roughly level on running cost unless it is well designed and reaches a high SCOP. The case rests on the EPC and on future rules, not on lower bills.

Flats: consent and the planning limits

With more than a third of households in purpose-built flats, most Southampton heat pump problems are building problems:

• Consent. A leaseholder landlord usually needs the freeholder’s or management company’s permission to fix a unit outside.
• Size. Under the England permitted development rules a compressor unit on a block of flats is limited to 0.6 cubic metres, against 1.5 cubic metres on a house.
• Noise. The 37.0 dB(A) permitted development limit applies, which is harder to meet where neighbours are close on every side.
• Position. No unit on a pitched roof under permitted development.

Read heat pumps for flats before you ask for quotes.

Article 4, licensing and conservation areas

HMOs. Southampton adopted a city-wide Article 4 direction on 23 March 2012. Changing a family house into a small HMO for 3 to 6 unrelated sharers needs planning permission anywhere in the city. If you are planning a conversion and a new heating system together, the planning question comes first.

Licensing. The national mandatory licence applies to any HMO with five or more people forming two or more households. Councils can add local additional or selective licensing on top, so confirm with Southampton City Council whether your property falls in a local additional or selective licensing area before planning works, and whether a heating change affects any licence conditions.

Conservation areas. Southampton’s conservation areas include Old Town North, South and West, Portswood Residents’ Gardens, Bassett Green Village, Uplands Estate, Oakmount Triangle, The Avenue and Carlton Crescent, and several carry their own Article 4 directions removing permitted development rights. In any conservation area, an air source unit is not permitted development if it is on a wall or roof that fronts a highway or sits nearer the road than the building. A listed building needs consent for any unit.

The geothermal heat network and heat network zones

Southampton already has a city-centre heat network. A June 2025 Heat Network Zoning report published by the Department for Energy Security and Net Zero describes the Southampton District Energy Scheme as a city-centre network running from 1986, which has used geothermal heat from the Wessex Basin aquifer. It is operated by Bring Energy in partnership with the council as the Southampton Geothermal Heating Company.

Southampton was one of 28 places in the government’s Heat Network Zoning Pilot. The study identified 18 potential heat network zones, three of them strategic, with anchor loads such as Southampton General and Princess Anne hospitals and the National Oceanography Centre. The report says its findings are provisional and should not be relied on for business decisions.

What it means for a landlord: if you own a city-centre block, ask about the network before choosing individual heat pumps. For a terrace or a suburban flat, an individual system remains the likely route.

EPC C, the climate plan and your duties

The same report records that the council declared a climate emergency in 2019, with a target of net zero for council buildings and operations by 2030 and city-wide carbon neutrality by 2035, and that its Green City Plan was launched in March 2020. These are council goals, not landlord obligations.

Your legal duties come from the EPC rules. Today the minimum is EPC E with a £3,500 cost cap. The government plans EPC C by 1 October 2030 with a £10,000 cost cap, but the regulations are not yet laid. Read does a heat pump improve an EPC rating and EPC C 2030 and your heating choice.

Grants and funding in Southampton

• Boiler Upgrade Scheme: £7,500 for air-to-water or ground source, £2,500 for air-to-air where it replaces existing heating. Landlords are eligible; an MCS installer applies on your behalf. See the BUS page for landlords.
• Warm Homes: Local Grant: through the Portsmouth-led consortium, £34,807,254 allocated. See the Warm Homes Local Grant page.
• Warm Homes Loan Scheme: a lender loan, not a grant, with private landlords eligible.

When a heat pump is the wrong answer

• A flat where the freeholder will not consent or there is no compliant position for the unit.
• A gas-heated home where tenants would pay more at 26.32p per kWh unless SCOP is high.
• A city-centre block that could connect to the heat network.
• A street-facing position in a conservation area.

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