Home insulation cost: what it really costs in 2026
A Qome Snap Guide: quick, honest and no guff. Approximate figures, adjusted to your region inside Qome.
Snap answer
£800 – £1,620 (loft & cavity)
Cavity wall insulation starts around £800 per house and loft insulation from £900. External wall insulation is the big one at £100–£160/m².
TakesHalf a day (loft/cavity) to 2–4 weeks (EWI)DisruptionMinimal for loft and cavity; EWI scaffolds the house
Cost at a glance
| Option | Best for | Guide range |
|---|
| Cavity wall | Injected, whole house | £800 – £1,200 |
| Loft top-up / full lay | To 270mm+ depth | £900 – £1,620 |
| External wall (EWI) | Solid-wall homes, rendered finish | £100 – £160 /m² |
Approximate guide figures, not quotes, Qome adjusts every price to your region.
What actually happens
- Survey, walls drilled-tested or loft measured
- Cavity: holes drilled in mortar joints and bead injected
- Loft: boards moved, rolls laid cross-ways to depth
- Pipes lagged and loft hatch insulated
- EWI: boards fixed to outside walls, mesh and render over
- Holes made good; certificates and guarantees issued
Price by region
Starting figures by region, the same honest baseline, adjusted for where you live.
London (Inner)from £1,250
London (Outer)from £1,100
South Eastfrom £950
East of Englandfrom £900
South Westfrom £850
Scotland (Highlands)from £750
West Midlandsfrom £750
North Westfrom £750
East Midlandsfrom £750
Scotland (Central)from £750
Yorkshirefrom £700
Walesfrom £700
North Eastfrom £700
Northern Irelandfrom £650
Popular choices
270mm+ loft depthBonded bead cavity fillEWI with brick-slip finishes
Rules & regulations
- Cavity and EWI should come with a 25-year CIGA or equivalent insurance-backed guarantee
- EWI changes the house's appearance, planning permission needed in conservation areas and on some street-facing walls
- Building regulations apply to EWI thermal performance
Snap tips
- Loft insulation is the best £-for-£ energy upgrade in the house, do it before anything fancy
- Never let anyone fill a cavity with damp problems; fix the damp first
Price it properly on Qome
Choose your options and see an honest, region-adjusted estimate, free.