Insulation Cost Calculator
The Insulation Cost Calculator estimates the install cost, annual savings, payback period and CO2 reduction for the main UK insulation upgrades — loft, cavity wall, solid wall (internal and external), under-floor and flat-roof. It also flags eligibility for ECO4 and the Great British Insulation Scheme.
Insulation Cost Calculator
Estimate costs and savings for different insulation upgrades.
See 20 real-world examples
Each link below runs this calculator with real UK city and property inputs and publishes the exact computed savings, payback time, install cost and CO2 figures.
- Cavity Wall Insulation Cost Calculator for Sheffield Homes
- Cavity Wall Insulation Cost Calculator for Southampton
- Cavity Wall Insulation Cost in Coventry
- Cavity Wall Insulation Cost in Swansea What You Need to Know
- Insulation Cost Calculator for Your Home
- Loft Insulation Cost Calculator for Birmingham Homes
- Loft Insulation Cost Calculator for Bristol Homes
- Loft Insulation Cost Calculator for Liverpool
- Loft Insulation Cost Calculator for Stoke-on-Trent
- Loft Insulation Cost for Your Glasgow Home
- Solid Wall Insulation Cost Calculator for Edinburgh
- Solid Wall Insulation Cost Calculator for Newcastle Homes
- Solid Wall Insulation Cost for Brighton Homes
- Solid Wall Insulation Cost for Manchester Homes
- Solid Wall Insulation Cost in Leicester
- Underfloor Insulation Cost Calculator for Cardiff Homes
- Underfloor Insulation Cost Calculator for Leeds
- Underfloor Insulation Cost Calculator for Nottingham
- Underfloor Insulation Cost Calculator for Plymouth
- Underfloor Insulation Cost in Belfast What You Need to Know
How this calculator works
Cost-per-m² and saving-per-m² figures are taken from the Energy Saving Trust's 2024-2026 advice updates and cross-checked with installer quotes. Insulation area is floor area × area-factor (1.0 for loft/floor, 1.3 for walls) × property-type multiplier (detached homes have more external walls than terraces). Savings convert to CO2 using the standard gas emission factor of 0.183 kg CO2e/kWh.
Sources & references
Frequently asked questions
Which insulation has the shortest payback?
Loft insulation top-up. For a typical 3-bed UK home, going from 100mm to 270mm of mineral wool costs around £400-£800 and saves £100-£200 a year — paying back in 3-5 years.
Cavity wall or solid wall — how do I tell?
Look at the brickwork outside. If you see only "stretchers" (long sides), the wall is almost certainly cavity. If you see alternating stretchers and "headers" (short brick ends), it's solid. Houses built before 1920 are almost always solid; after 1930 almost always cavity.
Will cavity wall insulation cause damp?
In most homes, no. Damp problems usually come from inappropriate installations (e.g. exposed coastal locations, walls with unrepaired pointing) or pre-existing damp that the insulation traps. CIGA-registered installers carry a 25-year guarantee against installation defects.
Can I get free insulation?
Yes, if you qualify for ECO4 or the Great British Insulation Scheme. Eligibility is means-tested — you usually need to receive qualifying benefits like Universal Credit or Pension Credit, plus have an EPC of D or worse. Apply via gov.uk or directly through participating energy suppliers.
How long does insulation last?
Loft insulation lasts 40+ years. Cavity wall insulation has a 25-year CIGA guarantee but lasts indefinitely if installed correctly. Solid wall systems have 25-year manufacturer warranties.
Tool: Insulation Cost Calculator. Last reviewed: . Figures based on Ofgem price cap, gov.uk grant guidance, and Energy Saving Trust advice. Verify scheme eligibility with your installer before commissioning work.