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Thermal Resistance Calculator

Free

Calculate wall thermal resistance R, check RE2020 and existing RT compliance.

Compliant with RE2020

🧱Wall type
📐Wall layers
mm

📊Result

🔥R total

3.92m²·K/W

❄️U (transmittance)

0.255W/m²·K

📏Total thickness

120mm

External wall — RE20203,9 m²·K/W

3.7 m²·K/W required

📐 Calculation formula
R = e / \u03bb (par couche)\nR_total = Rsi + \u03a3R_couches + Rse\nU = 1 / R_total

R = thermal resistance (m²·K/W), e = thickness (m), λ = conductivity (W/m·K), U = transmittance (W/m²·K). Rsi = 0.13, Rse = 0.04.

Standards & regulations

  • RE2020Réglementation Environnementale 2020 — Bâtiments neufs
  • RT existantRéglementation Thermique éléments par éléments — Rénovation
  • NF EN 12524Propriétés hygrothermiques des matériaux de construction

This tool provides indicative estimates. Results do not substitute professional advice. Always verify with current regulations.

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