Housing and Transport Expenditure: Socio-spatial Indicators of Affordability in Auckland

Abstract

There is a well-established body of literature concerning the negative environmental impacts of urban sprawl and associated levels of vehicle use. However, proponents of low density urban fringe development assert that urban sprawl is merely consumer preference writ large, and a means of urban development which is conducive to supporting housing affordability. Consequently, there is a strong ideological tension between environmental ideals and housing affordability in public debate. If housing affordability arguments are used to justify sprawl, then the definitions and methodologies of housing affordability need to be re-examined. Traditional measures of housing affordability are expressed solely as a function of housing cost and income. This one-dimensional view of affordability ignores transportation costs, which represent a sizable proportion of household expenditure. Conventional measures are problematic due to the extent to which housing location influences transportation costs. Consequently, narrowly construed definitions of housing affordability are misleading indicators of housing stress.

The present study quantitatively examined intra-metropolitan combined housing and transport affordability in Auckland. The research utilised disaggregate zonal data (largely derived from the 2006 New Zealand census) to develop comprehensive indicators of commuting costs. These indicators were applied to give an integrated affordability index for each statistical area unit within Auckland City. The results suggest that once commuting costs are incorporated into measures, a very different pattern of affordability emerges. Outcomes from this research will further a more comprehensive understanding of housing affordability across Auckland and will inform debate on issues such as urban growth strategies.