Degree Name

Doctor of Philosophy


Sustainable Buildings Research Centre


The present research project is designed to assist in decision-making of householders to determine beneficial strategies that improve energy performance of existing dwellings and reduce the cost of energy.

The focus of the thesis is on existing residential buildings and envelope improvements. A hybrid approach, combining the output of quantitative analysis and the qualitative assessment, was used to produce a set of ‘representative’ dwelling designs for the current residential stock. Quantitative analysis of accessible The Australian Bureau of Statistics (ABS) databases was undertaken on the Australian residential sector, focused on the investigation of building envelope characteristics. A qualitative investigation was carried out with focus on defining a set of New South Wales (NSW) housing typologies from experts and practitioners working in NSW residential energy-efficiency and building sector.

The outcome of the hybrid approach was used for the development of representative dwelling simulation models to aid the quantification of the potential for energy efficiency upgrades at the stock level, as well as aiding the related policy evaluation and development. The initial ‘representative’ dwelling designs matrix undertaken for this study produced a large number of representative dwelling simulation models, many of which were not substantially distinct from each other in terms of energy performance. For this reason, Taguchi and ANOVA methods were used to produce a reduced number of representative dwelling simulation models that incorporated significant attributes for the determination of the energy performance. The development of twelve representative dwelling simulation models was the main outcome of this analysis. Differential Sensitivity Analysis (DSA) was then undertaken for assessing the significance and influence of input design parameters on the amount of energy needed to maintain the indoor conditions of representative dwelling simulation models within an acceptable temperature range. Six key building design parameters were identified as having high influence coefficients through differential sensitivity analysis such as airtightness level, window-to-wall ratio (WWR), window types and the level of insulation for the ceiling, the wall and the floor.