Life cycle analysis of energy efficient measures in a tropical housing design

Energy conservation has become an issue of global significance, which is a focus reflected in the Australian housing industry's renewed emphasis on energy-efficient design. The Australian Building Codes Board (ABCB) has proposed to increase the stringency of the Building Code of Australia (BCA) to ensure the industry adopts energy efficient measures, including the enhancement of thermal performance and greater recognition of thermal mass in energy rating schemes. However, this proposal's potential to effect energy savings in tropical housing is yet to be assessed. In order to determine its relative merits under tropical conditions, a standardised house design used in the Tiwi Islands of the Northern Territory (NT) was subjected to life cycle analysis, including analysis of embodied energy, the efficiency of energy saving measures and the resulting active energy consumption. This standardised house, like others in the NT, is designed for retrofitting within 10 years, which reduces the time available for savings in operational energy to exceed energy invested in installing these measures. Housing lifespan would, therefore, significantly impact upon potential benefits resulting from changes to the BCA. In addition, the spatial distances between population settlements in the NT greatly increases embodied energy values. It was found that adopting the proposed measures would result in an increase in energy efficiency through a reduction in the need for refrigerative air conditioner use, and that the embodied energy payback period would fall within the lifespan of the house. Therefore, for this specific tropical design, the BCA's proposed measures for saving energy were found to be beneficial.