U-Value Calculator

Find the U-value of a wall, roof, floor or window. Build it up layer by layer from a material library, with air gaps, battens and surface resistances to ISO 6946, or pick the glass, frame and spacer of a window to ISO 10077-1. It also checks for interstitial condensation between the layers with the Glaser method of ISO 13788, at your design conditions and month by month over a year.

Units
Element
Surface resistances
Outside surface, Rse0.04
Inside surface, Rsi0.13
Total R – m²·K/W

Wall U-value

– W/m²·K

Section and temperatures

Design conditions

Interstitial condensation Glaser method, ISO 13788

Month by month ISO 13788, condensation and drying over a year