Integration of photovoltaic/thermal air-based systems into office facade retrofit projects using small scale decentralized heat pumps with low temperature short term storage using a radiant phase change material panel (RPCMP) is presented for a south facing office building perimeter zone. The concept can be applied in building facade retrofits, where both facade and mechanical systems are to be replaced. A numerical study is carried out for a case study building in Saskatoon, Canada. A numerical model is developed and the concept is theoretically compared to an all-air system for several consecutive design days. Electric power demand reduction of 14,5% for these design days can be achieved, if the facade integrated photovoltaic system would be supplying energy to the perimeter zone for heating and plug load applications. A reduction in heating coil heating power demand of 11.3% is achieved for the mentioned design days when compared to an all-air system. (C) 2017 Elsevier B.V. All rights reserved.