Property boundary change for residential development: a study of Brisbane, Australia

Abstract

To help counter the negative impacts of urban sprawl, the Queensland Government has introduced a policy of urban consolidation whereby Brisbane has a target of 94% of new dwellings being from infill development (Department of Local Government, Infrastructure and Planning 2017). Infill is the development within existing urban boundaries, and to reach such a level requires not only a transformation of the dwelling types being constructed (for example, a change in preference for detached houses to apartments), but also a transformation of the urban structure of the city. Like many metropolitan strategies, however, greenfield development within existing local government boundaries is included as meeting urban consolidation targets. Undeveloped land within existing urban boundaries is a finite resource meaning that, once such greenfield sites are utilised, infill of existing residential areas, or greyfield development, will be crucial at meeting urban consolidation targets by redeveloping existing urban areas at higher densities. Despite overarching planning schemes aimed at densifying existing urban areas, infill development in Australia is generally informal, lacking any specific government policy focus or intervention. Little scholarly research is available on how urban consolidation targets and infill are to be achieved in a practical sense. Multiple dwellings such as apartment buildings are denser and taller, therefore requiring larger footprints than a single dwelling. Due to the small size of existing residential lots, amalgamation is often required if properties are to redevelop at higher densities. Land amalgamation is a process where smaller parcels of land are merged to create larger parcels, effectively reverse subdivision. This alters the highly fragmented existing cadastral pattern and creates lots more suitable for redevelopment. This research uses two sets of property boundary data to compare the property boundary change occurring over a ten-year period to facilitate infill development in the Brisbane suburbs immediately south of the Central Business District. Amalgamation of properties for higher density residential developments are a specific focus of this study, as it is amalgamations that will be required to meet urban consolidation targets once more easily developed sites, such as former industrial or commercial areas, are no longer available for development. This study identified 182 boundary changes, a boundary change being an event of amalgamation, subdivision or reconfiguration, regardless of how many lots were involved. Changes occurred on two percent of lots within the study area, with greyfield development forming 66.5% of all redevelopments. These results, however, varied significantly between suburbs. For example, greyfield development formed most redevelopments in both East Brisbane and Kangaroo Point, but the former was generally a subdivision resulting in additional detached houses, whereas the latter was generally an amalgamation resulting in the replacement of detached houses with an...