The metropolitan region of Perth, Western Australia is home to around 1.6 million people with the population expected to grow to 3.5 million by 2050. Perth is characterised by very large, detached dwellings which make up around 80% of the overall housing stock. This contributes to a population density of around 1,000 people per square kilometre, around half that of Sydney. If the region continues with the current pattern of development Perth will need 3,000km2 to accommodate the population in 2050, doubling the size of the existing area. Perth already experiences significant traffic congestion and infrastructure capacity issues due to the narrow spread of development along the coast. Strategic planning documents highlight the need to increase the density of the region by doubling the current rate of infill development. Achieving this target presents a number of significant challenges, largely because the region is not familiar with the construction of medium and high density dwellings and the widespread public opposition to intensification within existing suburbs. This paper discusses the findings of a series of investigative panels held in Sydney and Perth which evaluated ways to overcome the barriers to infill development, particularly the challenges of delivering diverse and affordable housing in Perth, vital given the median house price in Perth is around $500,000 (£340,000). Framed within the context of the development process, the paper examines a series of recommendations at each stage of the process which could stimulate infill development. Analysis of Sydney, a city with a long history of successful infill development, offers a contrast. However, the paper describes how Sydney currently faces significant barriers to residential development, barriers very different from those present in Perth, many of which were caused by the global finance crisis with potentially long lasting implications for the housing market.