Population modelling has shown Australian buildings face a future where adaptation of the stock will become increasingly necessary to secure a sustainable future (CSIRO, 2002). Changes in population pose threats to sustainability in terms of the trend for increasing affluence and because there will be higher numbers of consumers using resources. Somehow Australia needs to buck the trend for larger buildings and avoid Jevsonís Paradox, whereby increases in energy efficiency lead to higher rates of consumption overall (CSIRO, 2002:27). Approximately 17% of all building activity in the Australian housing sector is refurbishment and alterations (ABS, 2008). Housing accounts for 59% of all work undertaken with 41% undertaken on non residential buildings. Though it not known in Australia what proportion of non residential work is adaptation, in the UK 46% of all building work is refurbishment and it was worth forty five billions pounds in 2003 (Douglas, 2006). Thus adaptation represents a significant proportion of construction expenditure annually with large amounts of resources expended in the improvement of building performance and utility. Questions arise, such as how are decisions made in terms of which buildings are adapted? Could this decision making be improved? What are the critical factors determining adaptation and reuse? What is re-use and how does it fit with other practices such as refurbishment, maintenance and renovation, and repairs for example? This paper identifies the rationale and need for adaptation and addresses some of the questions above.