Insulation R-Value Loss Calculator
Heat loss + payback period for upgrades
📚 Learn more — how it works, FAQ & guide Click to expand
Learn more — how it works, FAQ & guide
Click to expand
Insulation R-value loss calculator
How to use this tool
- 1
Enter walls + R-value
- 2
See heat loss + savings
- 3
Calculate payback
Frequently Asked Questions
R-value vs U-value?
R = thermal resistance (higher better). U = thermal transmittance (lower better). U = 1/R. EU uses U (W/m²K), US uses R (h·ft²·°F/BTU). 1 R-US ≈ 0.176 R-SI ≈ 5.68 U.
2026 building code?
EU passive house: U-wall ≤ 0.15, U-window ≤ 0.8. Building reno standard: U-wall 0.24, roof 0.20.
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