Hybrid buildings: pathways for greenhouse gas mitigation in the housing sector

This report shows how the carbon emissions from 5-star rated homes can be reduced to zero, with the savings averaging eleven tonnes per house each year. Australia’s housing sector, comprising over 7 million dwellings and their occupants (as well as associated industries), currently has no role in the Federal Government’s Carbon Pollution Reduction Scheme. This is despite the fact that this sector contributes approximately 54 million tonnes of CO2-e annually to the atmosphere – more than 10% of national emissions. This CPRS omission plus Government’s proposed compensation to households for the higher energy charges they will face once a carbon price is established will effectively remove any incentive for innovation in green building, distributed energy generation and energy efficiency initiatives and will serve to lock in poor performance (of dwellings) and wasteful behaviour (by households). Pathways to a carbon neutral housing future have been identified via a new class of hybrid building. Hybrid buildings can be defined as residential buildings that have a capacity to supply, in total , the annual operating energy requirements of their occupants by utilising locally generated (low or zero-emission) energy sources. At times when energy is generated surplus to its occupants’ immediate demands, energy is supplied to the grid and if the dwelling is unable to generate sufficient energy for autonomous operation, energy is received back from the grid. The Hybrid Building report demonstrates the pathways that current 5-star rated ‘project’ homes (with average emissions of 9.5 tonnes CO2-e per year) can take to achieve zero-carbon status, with savings in CO2-e emissions averaging eleven tonnes per dwelling per year. The report also identifies key transitions in hot water heating, space heating and cooling, built-in appliances and plug-in appliances that can significantly reduce domestic carbon footprints.