U-Value Calculator

Tool 11 · Building physics · EN ISO 6946

U-Value Calculator

Build a component layer by layer from a library of 130+ materials — R = d/λ per layer, surface resistances, timber-fraction bridging per the combined method — with the U-value worked out step by step.

Component & layers

Sets the surface resistances Rsi / Rse (heat-flow direction).

Interiortop
1mm

λ = 0.25 W/(m·K) · μ = 7 — g ≈ 11.3 kg/m²

2mm

λ = 0.13 W/(m·K) · μ = 40 — g ≈ 96.0 kg/m²

3mm

λ = 0.035 W/(m·K) · μ = 40 — g ≈ 1.8 kg/m²

4mm

λ = 0.7 W/(m·K) · μ = 15 — g ≈ 7.8 kg/m²

Exteriorbottom

Component build-up — interior to exterior

INTERIOR · Rsi = 0.13EXTERIOR · Rse = 0.04123Σd = 358.5 mm1Gypsum plasterboard (GKB) — 12.5 mm — λ = 0.25 W/(m·K)2Autoclaved aerated concrete PP2, ρ400 — 240.0 mm — λ = 0.13 W/(m·K)3EPS 035 (white) — 100.0 mm — λ = 0.035 W/(m·K)4ETICS base coat + glass-fibre mesh — 6.0 mm — λ = 0.7 W/(m·K)

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Condensation risk — Glaser method

With ArchiStructura Pro, the build-up is checked for interstitial condensation per EN ISO 13788 / DIN 4108-3: interface temperatures, vapour and saturation pressures, condensation planes and the accumulated condensate over the cold period — with the classic Glaser pressure diagram.

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ArchiStructura — Eurocode Student Toolkit

Based on EN 1990, EN 1991, EN 1992-1-1, EN 1993-1-1, EN 1995-1-1 & EN 1997-1.
Educational tool only — always verify against the National Annex and a qualified engineer. The full Eurocodes are published by your national standards body.