Integrated design strategies for renovation projects with Building-Integrated Photovoltaics towards Low-Carbon Buildings: Two comparative case studies in Neuchâtel (Switzerland)

As tomorrow’s cities are already largely built, and as many of their buildings have a low energy performance level, urban renewal processes are essential for the sustainable development of European cities. In this context, Building-Integrated Photovoltaic (BIPV) systems, using innovative PV products as new construction material for facades and roofs, can potentially provide a crucial response for achieving long-term carbon targets. This paper presents an integrated architectural design process for addressing renovation projects. Presented through a comparison of two case studies on archetypal residential buildings from the 1900s and 1970s in Neuchâtel (Switzerland), this approach includes the design of different renovation scenarios integrating passive, active and BIPV strategies. An optimization of the potential BIPV (or active) surfaces based on the annual irradiation threshold is conducted to maximize self-consumption (SC) and self-sufficiency (SS). The scenarios, before and after this optimization-based refinement, are evaluated in terms of Life-Cycle Assessment and Cost. Results demonstrate the importance of the optimization to ensure the cost-effectiveness of the strategy and increase the independence from energy suppliers. The main outcome provides, to architects and engineers, advanced BIPV renovation strategies along with results from a multi-criteria evaluation that are crucial for reaching carbon neutrality