Home Construction R-value Calculator

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This webpage calculates the R-value of walls, roofs and suspended floors for most insulation material R-values. It uses the "iso-thermal planes" method, the same method as used in NZS4214:2006.

Some of the possible material combinations may not be suitable for actual constructions, i.e. EPS based claddings directly fixed on timber framing. Please make sure to select only appropriate material combinations.

If your construction is not listed, please send an e-mail to designnavigator@gmail.com with a description and a detail drawing (pdf) of it or use the new Design Navigator message board.

Please select the element type. Then choose the construction details and enter the R-value of the insulation either directly in the text box or by choosing a product from the right panel.


Current NZS4218:2009 Schedule Method minimum R-value Targets (non-solid contruction) :
Zone 1Zone 2Zone 3
Glazing (vertical)R-0.26R-0.26R-0.26
Glazing (skylights)R-0.26R-0.26R-0.31
Australian Building Code Targets :
All Zones except NSWNSW



List of Insulation Products

The listed R-values are based on manufacturer information.

The selected R-value will be automatically transfered into the currently selected cell of the construction calculator.