Abstract: In this study, the self sufficiency of a photovoltaic (PV) system installed on the roof of a single house is assessed in its response to the particularly severe weather conditions of Canada. Since the local climate presents large daily and yearly temperature fluctuations, in addition to the presence of snow, drizzle and freezing rain the design of renewable energy systems is very challenging. This research presents the investigation of both passive and active solar designs for a Canadian house. Self and transfer admittances of all surfaces were calculated. Furthermore, the zone admittance matrix has been derived for three different harmonics of the weather inputs. An explicit finite difference model is used to calculate the temperature of the all nodes which are considered. Further, the equations resulted from the finite difference model are solved by MathCAD. The passive response of the house shows around 20°C difference between room-air and ambient average temperature in a winter day. The second part of this study includes the simulation of the PV system and house energy consumption. It has been carried out by use of PVSOL. Consequently, by making a comparison between total consumption of the house and the electricity production by a PV system, the self sufficiency of a PV system was evaluated. This system is theoretically self-sufficient since the designed PV system provides 70 kWh in a sunny winter day when the maximum required energy for the building is 30 kWh approximately.