Local environmental impacts of alternative forms of residential development

New Urbanism is often presented as an improvement over conventional suburban development along economic, social, and environmental lines. While the economic and social claims of New Urbanism have been investigated, relatively little work has examined the potential environmental impacts of New Urbanism as compared with conventional forms of suburban development. One of the challenges of studying the environmental impacts of New Urbanism is that it is still too early to evaluate adequately many sites, since most New Urban development is less than a decade old but it often takes several decades for vegetation and related ecological processes to establish. This paper attempts to address the gap in our understanding of New Urban environmental conditions by examining the relationship between residential-parcel vegetation abundance and specific components of residential form across the Greater Toronto Area (Ontario, Canada). While not explicitly comparing New Urban sites with other locations, this analysis illuminates how many New Urban design principles are related to vegetation conditions by focusing on those aspects of residential form that are addressed by New Urbanism-road pattern, neighborhood land use, and site-level characteristics-across a region with heterogeneous form. The results indicate that locations aligned with New Urbanism design principles do not necessarily support more vegetation than those areas based on more conventional suburban patterns, with many design principles having no relationship to vegetation abundance. The paper concludes by examining the planning implications of the results, and outlines future research needed to understand more fully the long-term impact of New Urbanism on local environmental conditions.