Use of double skin façade with building integrated solar systems for an energy renovation of an existing building in Limassol, Cyprus: Energy performance analysis

The high percentage of energy consumption by fossil fuels in the building sector in combination with climate change across the globe increased the need to move into more sustainable building practices. Thus, the integration of sustainable strategies and active solar energy systems into the design process is becoming a tool for the reduction of the energy demand and improvement of the energy performance of existing and new buildings. This study investigates the energy performance of an existing residential apartment building in Limassol, Cyprus before and after its energy renovation, using a double skin façade combined with building integration of active solar energy systems. The proposed research starts with the analysis of the existing building energy performance, focusing on the energy loads for cooling, heating, and artificial lighting. Subsequently, the results of the existing situation are evaluated using digital energy simulations, and the process moves on to the renovation and energy upgrade of the building by integrating the aforementioned systems. Energy-Plus simulations are performed where the proposed systems’ contribution to the energy reduction is investigated including their energy reduction potential. The before and after simulations are compared, with the focus to prove whether the systems can be viable in terms of decreasing the energy demands of the building. Finally, a life cycle cost (LCC) analysis is performed, to determine the viability of the enterprise. The performed research proves that the application of the double façade, consisting of three main features — a building integrated photovoltaic system (BIPV), glazing system and rambling planting, can combine the positive effects of each individual system, if there is a combined systematic approach on the architectural design of the building envelope. The combination of the above led to a reduction of 83.5% in the energy consumption of the building, from 94,321 kWh of the existing situation to the 15,563 kWh of the proposed one. This reduction includes the contribution from BIPV system, which amounts to 26,706 kWh/ year of primary energy — thus covering the 63% of the proposed consumption of the building. On the other hand, the LCC analysis sums that a careful combination of bioclimatic design and active solar systems, can have a viable payback period, which in this case is 13 years. The overall aim of this research is to determine whether the use of a double skin façade combined with integrated active solar systems constitute an energy and cost-efficient solution for the viable refurbishment of an existing building in the south-eastern Mediterranean area. © 2022 The Authors