A study of the thermal performance of Australian housing

In recent years there has been growing world-wide concern regarding energy conservation, the reduction of greenhouse gases and sustainability. In Australia, a significant proportion of the end energy usage in domestic buildings is used for space heating and cooling (Australian Greenhouse Office, 2004). Therefore, achieving better energy efficiency in buildings has become one of the major challenges for architects and builders. These concerns have been reflected at several levels within Australia with the establishment of responsible government agencies at both the Federal and State Government levels. Several new measures have been introduced to the building industry including an energy star rating system for all new residential developments prior to building approval. This rating system involves the estimation of the energy required to maintain the interior of the building within a set temperature range taking account of the building fabric, insulation, design, orientation and locality. A star rating is obtained by comparing the energy estimate against set values for the relevant climate zone. Failure to meet minimum criteria requires changes to the building design or fabric. Several packages such as NatHERS (NatHERS), AccuRATE (AccuRATE Manual) and FirstRate (FirstRate) are available to simulate building performance. Other models such as BASIX (BASIX and Building Code of Australia) also consider broader environmental issues such as water efficiency.