This paper presents the design and performance of a full scale building integrated photovoltaic/thermal system installed on a new office building in Montreal, Canada, latitude 45ºN. The building integrated system combines two solar technologies: commercially available unglazed transpired collector and custom designed photovoltaic modules. Covering 3100 square feet (288m²), the solar installation can produce 25kW of electricity for use within the building and approximately 260MBtu/h (75 kW) of preheated fresh air at a rate of 10000 cfm (4.7 m³/s). Measured combined efficiencies on the order of 50% show the potential of this technology for converting incident solar energy to high grade electricity andthermal heat for use in new or retrofit applications.