Implications of Urban Form on Suburban Food Production Potential: The Case of Auckland City-New Zealand

Abstract

This research examines the relationship between urban form and the contribution of urban agriculture to food energy requirements. It is an empirical study on suburban areas of Auckland, New Zealand, that investigates the impact of housing density on solar access, soil and rainwater collection for the purpose of food production. Three typical suburban residential blocks of differing density were evaluated using a modified Land Suitability Analysis with solar access, soil fertility and water availability as primary determinants of suburban agriculture. The results were then extrapolated to the cities of Auckland and Christchurch to determine what proportion of the cities have a degree of food resilience. The findings show that if 25% of the back and front yards of residential lots in low-density suburbs of Auckland and Christchurch were utilized for food production, they would contribute 9.4% and 12.3% respectively to the overall diet of those urban areas. This is a significant amount of food energy requiring virtually no energy to transport it from producer to consumer. On the other hand, medium and highdensity urban forms contribute less than 1% of the food diet in both cities. The original contribution to knowledge is that for urban agriculture to be effective, lower density suburban housing is required with a relatively large surface area exposed to solar radiation. Although this results in increased resilience and allows a degree of self-sufficiency, it conflicts with urban containment policies that view low-density suburbia as a high transport energy consumer. The thesis argues that this potential form of food energy should be balanced against the negative aspects of transport energy consumption associated with suburbia. Policy directed at containment of cities ignores the potential contributions from renewable energy, particularly solar, that can be used for biomass (food) or directly converted to electricity or home heating.