'Sustainable Urbanism' encompasses Australian urban design and transportation practices that seek to create vibrant, liveable communities. This approach proposes the creation of compact, walkable communities centred around high quality public transport systems for urban infill, brownfield and greenfields sites. The aim is to make it possible to live a higher quality life without complete dependence on a car for mobility and survival. Conventional suburban development practices need to change from single to mixed uses. More housing diversity is important to increase diversity in suburbs for the demographic changes facing Australia. Provision of local jobs helps to reduce car dependency as does a public transport-friendly layout of new developments. The Western Australian Liveable Neighbourhoods Code sets out spatial structuring elements of sustainable urbanism. The approach, together with initiatives to reduce household water and energy use underpins urban extensions in Perth. This note also examines the proposed new growth centres of Western Sydney.