Accounting for approximately 40% of the primary energy use and one-third of the global greenhouse gas emissions, buildings significantly contribute to climate change. Due to increased demand and improved lifestyle, energy demand in the residential sector is growing sharply, placing additional pressure on the energy system. Therefore, this sector has considerable potential for energy savings at the national level.
In an attempt to make energy more affordable for low earners, this study used various tools and techniques to respond to the questions “what are the key factors affecting the energy performance of the residential buildings?” and “to what extent is the energy performance of a building influenced by its occupants and their activities?”. The study revealed that the floor area of the dwellings, household size, and disposable household income, to a certain extent explain the variation in electricity consumption in the sample households. Monitoring the variation in indoor temperatures in a number of sample households with different types of the heating/cooling system further confirmed that thermal performance of buildings and the occupants’ status of thermal comfort are significantly affected by their behaviour with respect to ventilating the house and the use of heating and cooling systems in the dwellings.
Thermal performance assessment of the sample dwellings with AccuRate software, Australia’s benchmark tool for building energy assessment was performed using actual values for occupancy (number of occupants as well as heat gains from people), heat gains from lighting, key appliances, heating and cooling thermostat set-points, and time of use of appliances including heating/cooling systems. It was found that the AccuRate’s base assumptions under-predict the number of internal heat gains in the households and thus calculates a greater need for heating energy and a lesser need for cooling energy than is actually required. The thermostat settings of heating and cooling appliances were found to have the highest impact on the thermal energy requirements of the households. Occupant behaviour in the households resulted in a greater time of use of heating/cooling appliances with lower/greater temperature set-points than AccuRate’s base assumptions. This meant that taking all factors (occupancy, internal heat gains, time of use and temperature set-points) into account, the predicted actual total thermal energy requirements of the households were, on the whole, significantly greater than the total energy requirements calculated using AccuRate’s base assumptions. Further, it was found that significant total thermal energy savings of up to 50% – 70% could be found in households with adjustable thermostats if they followed the recommended thermostat guidelines of this study.
Overall, this research provides an insight into the energy performance of social housing dwellings in Perth, Western Australia. With these buildings constructed similar to the average residential buildings in Australia, the findings from this study may be further extended to the residential sector in Perth. However, evaluating the energy performance of a bigger sample of households is required for validating the outcomes