Dr Peter Mitchell will outline an approach to this question by describing the predictions of climate change in Sydney, Melbourne and Adelaide, and the relationships between climate and reactive soil movements. Thornthwaite Moisture Index (TMI) as used in AS 2870-1996 “Residential slabs and footings” will be described, and shown to be related to seasonal soil movements in the three cities. The effect of climate change predictions for Sydney, Melbourne and Adelaide on soil movements and the implications for footing design will be discussed. The effect is quite dramatic for Melbourne, and footing sizes for articulated masonry veneer construction used at present, and as predicted in 2030 and 2070 will be developed for Melbourne by using the computer program SLOG.