Equal numbers of samples of housing units, with known insulation, fenestration and area characteristics, built along east-west and north-south oriented streets respectively, will be compared in the Ottawa, Canada Metropolitan Area. For each sample, figures on annual space heating expenditure by the owners of the units will be obtained from a pertinent question in the 1986 Canada Census as a basis for the comparison. The purpose of the research is to determine if the often hypothesized superiority of east-west oriented streets for passive solar heating bears out for a large number of ordinarily built and occupied housing units.