Important notice
Every older property is unique. This guide covers general considerations, but your home needs a professional survey by an MCS-certified installer who understands retrofit work. We are not heating engineers or surveyors.
Common challenges in older properties
Fabric
Solid walls
Pre-1920s homes typically have solid walls without cavity for insulation. Heat loss through uninsulated solid walls is significant.
- · Internal wall insulation (loses some room space)
- · External wall insulation (changes exterior appearance)
- · In England, may be funded through the Warm Homes: Local Grant
Air leakage
Draughty construction
Older homes often have gaps around windows, doors, floorboards, and chimneys that allow significant heat loss.
- · Draught proofing (relatively low cost)
- · Chimney balloons or caps
- · Secondary glazing for period windows
Heat output
Undersized radiators
Heat pumps operate at lower flow temperatures (35–45°C vs 60–80°C). Existing radiators may be too small to heat rooms adequately at lower temperatures.
- · Larger radiators in key rooms
- · Underfloor heating where possible
- · Fan convectors for problem rooms
Heritage
Listed buildings
Listed buildings face restrictions on external changes. External wall insulation and visible heat pump units may need planning permission or listed building consent.
- · Internal insulation (usually permitted)
- · Carefully positioned outdoor unit
- · Consult conservation officer early
Heat pump suitability by property era
Victorian & Georgian
Solid walls, single glazing, minimal insulation. Highest heat loss but also highest grant potential. Likely needs comprehensive insulation programme before heat pump installation.
Priority for grant funding due to low EPC ratings
Edwardian & inter-war
Mix of solid and early cavity walls. Often good room sizes with space for larger radiators. Loft insulation and draught proofing usually the first priorities.
Good candidates with targeted insulation improvements
1930s–1960s
Many have unfilled cavity walls — cavity wall insulation is a quick, cheap improvement. Often already have loft insulation. Generally good candidates for heat pumps with modest preparation.
Often straightforward with cavity wall insulation
1970s–1990s
Cavity walls (some already insulated), double glazing common. Building regulations improved insulation. These properties are often well-suited to heat pumps with minimal preparation.
Good candidates — may only need radiator assessment
Check your ECO4 eligibility
Older properties with low EPC ratings are what ECO4 is aimed at, though eligibility depends on the household as well as the property
Key eligibility factors:
- Open now — the installation must be completed by 31 December 2026
- England, Scotland or Wales (not Northern Ireland)
- On a qualifying benefit, in social housing rated EPC E–G, or referred through ECO4 Flex by a council that takes part
- Eligibility is not a guarantee — suppliers decide which measures they fund
Check your property against the live MHCLG EPC register to see your current band and the schemes you may qualify for — free, in under a minute.
Check your propertyThe retrofit process
EPC assessment
Get your current rating and identify priority improvements. Your EPC band is one of the things grant schemes are assessed on.
Insulate first
Insulation before heat pump. In England, the Warm Homes: Local Grant may fund loft, cavity and solid wall insulation for eligible homes.
Heat pump survey
MCS installer assesses the improved property and recommends the right size and type of system.
Install & grant
Installer applies for the £7,500 BUS grant and installs the system in your prepared home.
Get expert advice for your older home
Connect with MCS-certified installers experienced in retrofit installations for older properties.
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Related guides
Insulation
Solid wall insulation
The essential first step for older homes. Internal and external options for solid-wall properties.
Read guide →EPC
Improve your EPC rating
Older homes often have low EPC ratings. See how insulation and a heat pump can transform yours.
Read guide →Grant
Insulation grants for older homes
In England, the Warm Homes: Local Grant may fund insulation in older, less efficient properties — your council decides. The other UK nations run their own schemes.
Read guide →Your older home deserves modern heating
Government grants may fund both the preparation and the heat pump, depending on which UK nation you live in and your circumstances. Find out which schemes your home may qualify for.