November 7, 2019
(This research was presented by Melissa James at the Improving Residential Energy Efficiency (IREE) conference held in Brisbane in April 2019)
New residential buildings in Australia are subject to the energy efficiency provisions of the National Construction Code (NCC). When designed and built they must meet a prescribed minimum standard. Whilst this confers some protection to future occupants against poorly performing homes, in the interests of energy equity it is worth exploring whether the energy efficiency of dwellings being built in areas of lower socio-economic advantage differ at all from those being built in more socio-economically advantaged areas. It is more difficult and costly to maintain a comfortable and healthy temperature in a dwelling which is less energy efficient.
Using Nationwide House Energy Rating Scheme (NatHERS) certificate data and Australian Bureau of Statistics (ABS) socio-economic indexes for areas (SEIFA) data, this study found that in Australia, new houses (NatHERS class 1) planned to be built in more advantaged areas tend to have lower energy efficiencies than new houses planned to be built in less advantaged areas. On average, there was nearly one star difference between houses in least advantaged areas compared to houses in the most advantaged areas. This may be due to larger window/floor ratios in houses in the more advantaged areas. The differences in star ratings varied for each State and Territory (Table1).
| State/Territory | NCC Class | Min SEIFA (least advantaged) | Max SEIFA (most advantaged) | Star difference | p-value | Certificate count |
|---|---|---|---|---|---|---|
| Australia | House | 636 | 1181 | -0.9 | <0.0001 | 313785 |
| ACT | House | 1047 | 1171 | 0.3 | <0.0001 | 3963 |
| NSW | House | 671 | 1181 | -0.9 | <0.0001 | 88160 |
| NT | House | 690 | 1110 | -0.5 | <0.0001 | 1655 |
| Qld | House | 636 | 1148 | -1.3 | <0.0001 | 50644 |
| SA | House | 743 | 1127 | -0.1 | 0.0014 | 10644 |
| Tas | House | 811 | 1089 | -0.3 | <0.0001 | 7174 |
| Vic | House | 635 | 1160 | -0.1 | <0.0001 | 143404 |
| WA | House | 717 | 1168 | -1.1 | <0.0001 | 8141 |
