A typical small 3-storey office with a total floor area of 4200m2 was modelled in the Energy Efficiency Measure module of RETScreen [14] with the TMY weather data used in the TRNSYS simulations. This software is meant for pre-feasibility studies, but it was used in this case to easily compare the building space heating and cooling energy requirements of the different scenarios and avoid the complexity of multi-zone building simulation tools. The building lighting, equipment and appliances load, occupant density, natural air infiltration, ventilation rates and schedules were set to typical values for small office buildings [15]. The windows on all the non south-facing facades

were assumed to be fixed, low-e, triple-glazed and to have an overall U-value and SHGC of 1.57 W/m2oC and 0.27, respectively. The percentage of fenestration was set to 20% on the north wall and 40% on the east and west facades. The other building envelope properties for each city were selected to fulfil the minimum requirements of the Model National Energy Code for buildings (MNECB) [16] with oil selected as the principal heating source for Iqaluit and Yellowknife. The substitution of spandrel panels with multi-glazing BIPV systems was considered to have negligible effect on the lighting load.