The impact of urban form on residential space-conditioning energy use has been controversial in recent planning literature. This study empirically evaluates the association between urban form and residential energy use, focusing particularly on residential electricity use for space cooling in the City of Sacramento, California. We characterize urban form, property conditions, and demographic and socioeconomic characteristics by applying spatial metrics embedded within a geographic information system where LiDAR data effectively include each building and the surrounding vegetation. A statistical model is applied to assess the relationship between these explanatory variables and the estimated summer air-conditioning energy use. Controlling for other variables, higher population density, east-west street orientation, higher green space density, larger vegetation on the east, south, and especially the west sides of houses, appears to have statistically significant effects on reducing summer cooling energy use. This study quantifies the built environment impact on the energy demand of air conditioning and informs planners as they craft urban planning and design policies for energy conservation.Keywords: building energy use, passive solar community design, tree planting, GIS 1 Introduction Does urban form have an impact on the energy use of buildings? Conventionally, the energy consumption of buildings has been explained as a function of 'internal' determinants such as building design, energy system efficiency, and occupant behavior. For example, Baker and Steemers (2000) reported that building design can affect energy consumption by a factor of up to 2.5, system efficiency by a factor of up to 2, and occupant behavior by a factor of 2. If a building is poorly designed, equipped with inefficient mechanical systems, and occupied by energy-wasting occupants, it could consume up to ten times more energy than when looking at the best possible scenario (Baker and Steemers, 2000).Later Ratti et al (2005) added 'external' urban geometry to this formula when they compared three different building layouts, and reported that urban geometry leads to a variation in energy use with a range of approximately 10%. Although urban form may appear to have relatively little impact on energy use in buildings, its long-term impact across thousands of buildings can bring about a substantial difference due to the inertia of the built environment. Despite this long-term macroscale impact of urban form and the considerable contribution (40.36%) of buildings to total energy consumption (US Energy Information Administration, 2011) in the United States, the impact of the external physical environment on buildings' energy use has not