Comparing the energy performance of Australian houses using NatHERS modelling against measured household energy consumption for heating and cooling

• We apply heating and cooling (NathERS regulatory) energy simulations over a wide range of star ratings for 2 sets of Australian houses.
• We also monitor the actual thermal energy use across these sets of houses over several years.
• We compare the rating from the thermal simulation to the actual energy use.
• We measure and establish the trend towards lower energy use by higher energy (star) rated homes.
• We argue that Regulatory Thermal Energy simulations are a valid means to increase house energy performance.

The rating of buildings using thermal models represents a contrasting regulatory approach to prescriptive measures to improve the energy efficiency of buildings. This paper investigates the relationship between measured household energy use for thermal comfort purposes and the modelled thermal energy calculated under the Nationwide House Energy Rating Scheme (NatHERS), which is used for the regulation of minimum energy performance standards for new housing in Australia. Two different sets of housing in Adelaide, South Australia which were built a decade apart and to significantly different energy performance standards represent the basis of this study. The results show that better insulated houses represented by higher stars under the NatHERS scheme do use less energy for heating and cooling.