A cold house isn’t just uncomfortable — it’s expensive. These are the 8 most common reasons UK homes feel cold even with the heating on, what each solution costs, and whether you might be able to get Government help with the fix.
Most cold UK homes have a combination of issues. The table below ranks them by how much heat each one costs you, and what fixing it typically involves:
| Problem | Heat lost | Typical fix | Cost | Grant available |
|---|---|---|---|---|
| Uninsulated/underinsulated loft | Up to 25% | Loft mineral wool 270mm | £300–£900 | ECO4 / WH:LG |
| Uninsulated solid walls | Up to 35% | External wall insulation | £8,000–£20,000 | ECO4 / WH:LG |
| Unfilled cavity walls | Up to 35% | Cavity fill injection | £1,600–£2,800 | ECO4 / WH:LG |
| Cold/draughty floors | ~10% | Underfloor insulation | £1,400–£2,500 | WH:LG |
| Poor heating controls | Varies | Smart thermostat/TRVs | £150–£500 | WH:LG |
| Draughts (windows/doors) | ~15% | Draught-proofing, seals | £50–£400 DIY | — |
| Old inefficient boiler | Varies | New condensing boiler / heat pump | £1,800–£3,500 | BUS heat pump |
| Single/old double glazing | ~10% | Double/triple glazing | £4,000–£12,000 | — |
The most likely cause is insufficient loft insulation. If your loft has less than 270mm of mineral wool, or older loose fill insulation, heat is escaping through the roof. Loft insulation is the highest-impact improvement for most UK homes.
Cold external walls usually indicate solid walls (pre-1920s homes) or unfilled cavity walls (1920s–1990s). Touching the inner face of an external wall in winter tells you a lot — solid walls feel much colder than insulated cavity walls.
Suspended timber floors (common in pre-1945 properties) allow cold air to circulate beneath the floorboards. Underfloor insulation installed from the crawl space can make a significant difference.
This typically indicates poor insulation overall — the house cannot retain heat. Loft and wall insulation address this. Cavity wall insulation is one of the most cost-effective first steps if your walls are uninsulated.
Many of the measures that fix a cold home are covered by current Government schemes:
ECO4 (open to December 2026): Loft insulation, cavity wall insulation and external wall insulation may be fully funded for eligible households receiving qualifying benefits or with low household income.
Warm Homes: Local Grant (open now): Broader eligibility than ECO4. Covers insulation, heat pumps, solar panels and smart controls. EPC D–G, income up to £36,000 in England.
The most common reasons are: insufficient loft insulation (up to 25% of heat escapes through the roof), uninsulated walls (up to 35% through walls), and draughts through floors, windows and doors. A professional survey or SAP energy assessment can identify which is the biggest factor.
Heat rises but escapes through an uninsulated roof. If you have less than 270mm of loft insulation (or no loft insulation), heat generated downstairs warms the loft space and escapes through the roof rather than staying in the bedrooms.
Draught-proofing is the cheapest and quickest immediate improvement. Fitting draught excluders to doors, sealing skirting board gaps and blocking unused chimneys can be done in a day for £50–£200 and you notice the difference immediately. For the highest-impact medium-term improvement, loft insulation delivers the best return for most properties.