Comparative Parametric Assessment of Roof- and Facade-Integrated Photovoltaic Systems for Multi-Story Student Residence Halls

This paper examines the energy renovation of buildings using building-integrated photovoltaic (BIPV) systems applied to facades and roofs. Although BIPVs are increasingly recognized as a vital component of sustainable retrofit strategies, designers still lack comparative decision-support tools for the simultaneous technical and economic evaluation of roof- and facade-integrated (envelope-integrated) configurations. To address this gap, this study presents a methodology for the energy-efficient retrofit of multi-story student residence halls through a parametric analysis. This comparative approach evaluates energy performance and electricity production while estimating the associated costs of BIPV systems. Building upon prior research, the current analysis utilizes innovative, energy-optimized models to form the basis of computer simulations. The methodology relies on a fundamental assumption involving an arbitrary parameter that defines grid-energy substitution rates by BIPV-generated electricity. Regarding the economic aspects, the results indicate that while certain rooftop installations offer lower costs and shorter payback periods than facade systems, other rooftop configurations exhibit higher costs and extended payback periods. This research provides valuable insights for optimizing civil engineering solutions in photovoltaics, where local electricity production effectively replaces grid-supplied energy. Furthermore, the proposed innovative qualitative and quantitative input/output models can be extended to parameterize other building renovation characteristics within civil engineering methods.