Page 883 - Week 03 - Wednesday, 20 March 2019
Next page . . . . Previous page . . . . Speeches . . . . Contents . . . . Debates(HTML) . . . . PDF . . . . Video
years. That is why the relevant climate data in most energy modelling methods is based on average weather over decades. It results in a more accurate assessment of the climate and a more reasonable basis for assessing the general efficiency of the building.
In contrast, the Bureau of Meteorology defines a heatwave as three or more days of unusually high maximum and minimum temperatures in any area. There is, therefore, an important distinction between standards for climate and standards that relate to heatwaves. If the weather we experienced this past summer becomes the norm—and it may—then it will come to be recognised as usual weather in updated climate data and the general standards will adjust. So general efficiency ratings do not require buildings to be designed for unusual weather.
It is also important to consider that, while we may expect hotter summers, in Canberra we will still have relatively cold winters. In trying to address warmer weather we cannot ignore that for many months of the year we still need homes designed and built to keep us warm. It is relatively easier to design a building for one type of weather; it is more difficult for a building to be designed to respond well to both cold and hot weather such as we experience in Canberra.
In the winter we want our buildings to warm up quickly and to keep their heat as long as possible and we want the opposite on hot days. So what may work well in one part of the year may, indeed, not work well in another. That is why a building that performs well in hot weather or extreme heat maybe very uncomfortable for most of the year in Canberra, and that is why a home designed to use less energy over the long colder season, which is generally more efficient, may not do very well in summer or in short runs of hot weather.
Further, a home with a low energy rating may be able to cool down better in hotter weather in comparison to one with a higher energy rating. So the issue is not necessarily a matter of aiming for higher ratings; nor is it a compliance issue. Here in the ACT information on new buildings designed since 2017 indicates that many ACT residential dwellings are already reaching high ratings, with a range of between six and nine stars. Over 90 per cent of apartments and 50 per cent of houses and townhouses modelled at 6.5 stars or above. The average across all dwellings is seven stars.
Obviously that is not to say that we do not think compliance is important. As members would be aware, we have increased actions for non-compliance with building laws and standards. There is also a long-running auditing program for residential energy efficiency ratings, and the government reports annually on the number and the outcomes of these audits. The data tells us that we need to look past ratings to set the most appropriate standards and to establish what we want buildings to achieve. We need good, thoughtful design. It is also why there may need to be a range of different requirements rather than relying on general energy ratings. Rating tools have their place, but they cannot be expected to do everything.
The Australian Building Codes Board recognised that the energy rating pathway does not necessarily lead to buildings being efficient in both winter and summer, so it has
Next page . . . . Previous page . . . . Speeches . . . . Contents . . . . Debates(HTML) . . . . PDF . . . . Video