Comparison of energy consumption between the old and modern houses in Sydney

In Australia, traditional low thermal mass houses are being replaced by modern high thermal mass houses. At the same time, houses are becoming increasingly larger with fewer external open spaces. The larger houses, despite needing higher energy, must be more efficient to reduce the residential sector energy demand and emission burden of the nation. The residential sector is responsible for 25% of Australia’s total energy consumption [1]. A number of strategic approaches has been taken to improve energy performance of the residential sector including green building rating schemes and appliance efficiency and incentive programs. The introduction of the Building Sustainability Index in New South Wales (NSW), Australia, is one example [2]. Despite improvement in building energy efficiency, larger building sizes per family, extravagant lifestyles, and increased heat stress due to climate change have greatly influenced residential sector energy consumption. The cooling and heating loads comprise 40% of residential electric energy consumption. As such, significant reduction in energy consumption can be achieved by improving house designs, ventilation, and insulation [3]. Among the many methods of improving residential building energy performance [4], this chapter focuses on the impact of thermal mass on improved energy performance of residential buildings by comparing older and newer designs of buildings in Sydney, Australia