This study assesses the potential energy savings from passive solar design for new Canadian single-family dwellings across eight representative climate and population zones - Vancouver, Prince George, Yellowknife, Edmonton, Winnipeg, Toronto, Ottawa and Halifax. Eight passive solar design scenarios applied to two house designs were analyzed in terms of (i) reducing annual HVAC energy consumption and (ii) solar heating fraction. A calibrated model of the Canadian Centre for Housing Technology Twin Houses was developed using EnergyPlus and provided the simulation platform for this research. The results show that with basic passive solar design measures, solar gains contribute a considerable fraction of a typical single-family dwellings heating requirements in cold climates such as Canada (21-32%) with optimized passive solar designs attaining significant higher percentages (32-74%). This is generally higher than other similar studies. Based on the results very large solar fractions can be achieved with optimized passive solar design. The results of this study have relevance to individual building design as well as planning decisions regarding density and urban design. (C) 2015 Elsevier B.V. All rights reserved.