Energy in New Zealand houses: comfort, physics and consumption

The Household Energy End-use Study (HEEP) quantified how, where, when, and why energy was used in New Zealand houses based on the monitoring of energy and end-uses in a national sample of 400 houses. Based on these data, space heating was found to average 34% of total household energy use. Three issues are highlighted in relation to space heating: firstly, the extent to which low indoor temperatures are associated with persistent under-heating; secondly, whether some space-heating sources tend to be associated with higher (or lower) winter indoor temperatures than others; and thirdly, what the drivers of under-heating might be. An overview of the HEEP research and its complex data set is provided. The range of winter indoor temperatures are then compared with international benchmarks and established healthy temperature ranges. Occupants' perceptions of winter indoor temperature conditions are presented and explored in relation to heating patterns and household energy consumption. The impacts of this research have assisted in changing public policy, moving from a narrow focus on energy efficiency toward an integrated energy, environmental, and health policy for the building stock and future interventions.