The objectives of this work are to model a group of test case houses using a high-resolution building simulation program, to evaluate the efficiency of internal combustion engine (ICE) based cogeneration and to determine the economical (in terms of fuel cost) impact of using ICE based cogeneration systems for residential use. The performance in terms of electrical and CHP efficiencies of the ICE based cogeneration systems in Canada were investigated and it was determined that the performance of the ICE based cogeneration system is dependent on the thermal and electrical loads of the house, on climate, especially the severity and duration of the heating season, and on the constructional characteristics of the house. Although the annual fuel cost of the household would increase, the ICE based cogeneration systems can provide savings in various aspects regarding electricity production and distribution. (C) 2009 Elsevier B.V. All rights reserved.