Quantitative exploration of winter living room temperatures and their determinants in 108 homes in Melbourne, Victoria

Indoor temperatures are key mediators of housing related health outcomes. In Australia, policy makers have implied improved thermal comfort and better health through more stringent residential energy efficiency, yet empirical evidence is scarce. This study used temperature measurements in the living rooms of 108 detached houses in Melbourne, Victoria, to calculate indoor temperatures indices, assess them against health based guidelines and to explore the association of indoor temperatures with household characteristics and the homes' energy efficiency AccuRate star ratings. The mean home energy rating was 4.7 ± 0.82 AccuRate stars. The mean winter room temperature was a satisfactory 18⁰C, yet occasional over- and underheating may have adversely impacted health. Continuous occupation and heater use as well as higher energy costs were significant predictors of warmer living rooms. Star ratings were a poor predictor of indoor temperatures. Possible reasons are discussed. The findings were limited by the small, non-representative sample and the reliance on self-reported fuel expenditure. The findings highlighted that a residential energy efficiency rating tool may need to be complemented by built quality controls and consider the efficiency of the heating system in order to be predictive of satisfactory indoor temperatures. More research into the heating practices of householders is needed.