Heat Loss & Insulation Savings Calculator UK
Estimate how much heat you’ll save—and money you’ll keep in your pocket—by upgrading insulation. Enter your area, current and proposed U-values, temperature difference, heating hours and energy price.
How It Works
Heat loss per year = area × U-value × ΔT × hours ÷ 1000 ⇒ kWh. Savings = (lossold − lossnew) × price. Total annual savings in kWh and £ are shown above.
For deeper insight, see our Home Insulation Best Practices.
Insulation Types
Common options include mineral wool, PIR boards or blown-in cellulose. Compare in our Best Insulation Materials 2025.
Installation Methods
Cavity, loft and solid-wall methods differ in cost and impact. Learn more in our Insulation Installation Methods.
Grants & Funding
Check government schemes like ECO4 for free or subsidised insulation. Details in our Insulation Grants Guide.
Key Values
| Entity | Attribute | Value |
|---|---|---|
| Insulation Project | Area | m² |
| Insulation Project | U-value before | W/m²·K |
| Insulation Project | U-value after | W/m²·K |
| Insulation Project | ΔT | °C |
| Insulation Project | Hours | hrs/yr |
| Insulation Project | Energy price | £/kWh |
Frequently Asked Questions
What is a U-value?
A U-value measures heat flow (W/m²·K); the lower, the better the insulation.
What ΔT should I use?
Use the average indoor-outdoor temperature difference (15–20 °C typical in the UK).
How many heating hours per year?
An average UK home runs heating 1500–2500 hours annually; adjust for your usage.
How accurate is this?
Results use standard physics; for precise figures, input measured U-values and local rates.
