TECHNOPOL SA← technopol.co.za
Free tool · ISO 6946 build-up

R-Value Build-Up Calculator

Layer up a roof, wall or floor and read the total R-value and U-value, with the surface films handled for you — then check it against the SANS 10400-XA deemed-to-satisfy minimum for your climatic zone.

1 · The assembly

Layers are listed outside → inside. Surface films are added automatically.
A printable record of this build-up that shows where every conductivity in it came from — and carries a QR code anyone can scan to re-check those sources against our live test register.
Assistive, not a compliance certificate. This computes a one-dimensional R-value through the layers you enter (ISO 6946). It does not account for thermal bridging by rafters, studs, brackets or fixings, which can be significant — use the Junction Thermal-Bridge Lab for that. It does not assess fenestration, orientation or the rational-design route. Confirm compliance with a competent person against the current SANS 10400-XA and SANS 204.
Technopol SA (Pty) Ltd · info@technopol.co.za · +27 11 363 2780 · A free planning aid — not a substitute for a rational assessment by the responsible professional.