The current research presents the design and development of a prefabricated modular façade solution for renovating residential buildings. The system is conceived as an industrialised solution that incorporates solar harvesting technologies, contributing to reducing energy consumption by employing an “active façade” concept. One of the main challenges was to achieve a highly flexible solution both in terms of geometry and enabling the incorporation of different solar-capturing devices (photovoltaic, thermal, and hybrid). Therefore, to be able to provide alternative customised configurations that can be fitted to various building renovation scenarios. Guided by the requirements and specifications, the design was defined after an iterative process, concluding with a final system design validated and adopted as viable for the intended purpose. A dimensional study for interconnecting all the technologies composing the system was carried out. Potential alternative configurations were assessed under the modularity and versatility perspective, resulting in a set of alternative combinations that better fit the established requirements. Complementarily, the system also integrates an active window solution a component that incorporates an autonomous energy recovery system through ventilation. The main outcome is explicated in a highly versatile modular façade system, which gives existing buildings the possibility to achieve Nearly Zero Energy Building requirements.