Life cycle water analysis of a residential building and its occupants

Reduced water consumption is one of the objectives of many towns and cities as part of the trend towards more sustainable settlements. Information on comprehensive water usage is required for formulating conservation and management strategies. Whilst buildings are directly responsible for only 12% of global water consumption, they can indirectly account for a much more significant proportion of total water demand due to the production of construction materials as well as the goods and services purchased by their occupants. This paper analyses both direct and indirect water consumption of a conventional Australian residential building and its occupants over a 50-year period. Input-output analysis is used to comprehensively determine total water usage. The results show that the direct water consumption to operate the house is only 6.4% of the total, with a further proportion embodied in the materials of the dwelling. The water embodied in consumable items, especially food, is the most significant, representing 46% of total household water demand. Policies for minimizing water consumption should address more than just direct water usage and the findings used to influence the design of urban living in the future.