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R-value

The R-value is a measure of the total thermal resistance of a building element to heat flow when the internal and external environments are constant.

Determining R-value

The BRANZ House Insulation Guide provides R-values for a range of timber wall, roof and floor constructions. Methods for determining the R-value of constructions that fall outside the scope of the BRANZ Guide are given in NZS 4214: 2006 Methods of Determining the Total Thermal Resistance of Parts of Building.

For information on determining R-value and the thermal conductivity of wood, download the PDF below.

R-value and thermal conductivity of wood - Printable PDF