🔥 Insulation Calculator

Use or Calculator to work out your U-values or to see how much you could save

Calculated U-Value
W/m²K
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Outer Leaf

Cavity

🟦
Climabead CWI
λ = 0.033 W/mK (full cavity fill)

Inner Leaf

Building Regs Reference Targets
New build (Part L 2021)≤ 0.18 W/m²K
Existing dwelling retrofit≤ 0.30 W/m²K
Typical pre-insulation wall~1.0–1.6 W/m²K
Calculated U-Value
W/m²K
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Insulation

Ceiling Finish

Building Regs Reference Targets
New build (Part L 2021)≤ 0.15 W/m²K
Retrofit / top-up target≤ 0.16 W/m²K
Uninsulated loft (typical)~2.0–2.3 W/m²K
Estimated Annual Savings
You could save about £— every year
Energy saved
kWh / year
Bill reduction
£—
per year
CO₂ saved
kg / year

What are you insulating?

Property Size

Thermal Performance

Heating Fuel

Ready to start saving?

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Indicative calculations using ISO 6946 method. Savings estimates use UK Ofgem price cap (April–June 2026) and heating degree days of 2,100 (UK average, base 15.5°C). Actual figures vary with construction, occupancy, and local climate. For certified figures, contact us for a survey.