In the field of ESD, two terms which constantly appear are the U and R values of products, but what do these mean? Whether referring to insulation or glazing each product on the market has a specific either U or R value. These values refer to the thermal performance of specific products and materials and how they assist in maintaining thermal control in a building or structure. These values are an integral part of the BASIX, NatHERS and Section J process in the NCC, which require specific values to be either entered into the glazing calculator for Section J reports or specific glazing types with predetermined U and SHGC values for BASIX and NatHERS along with specific R values for insulation and building materiality.

The NCC sets a minimum acceptable thermal performance for residential dwellings by specifying a minimum 6 star rating for all new projects in Australia with the exception of NSW who are under the BASIX programme.