Passive Thermal Performance of Glazed Balconies from Northern Portugal Vernacular Architecture and Contribution to a Regenerative Built Environment

The construction industry faces significant environmental challenges that necessitate a regenerative approach and the use of local resources. Features such as glazed balconies can dramatically lower energy consumption and carbon emissions. This research investigates the impact of glazed balconies through a case study of vernacular architecture in Northern Portugal, emphasising their function as passive heating systems that capture solar energy while minimising heat loss. The methodology involves short-term and long-term thermal condition monitoring and occupant comfort surveys. The quantitative findings demonstrate that glazed balconies alleviate indoor discomfort during sunny days in the heating season by effectively utilising solar gains. However, overheating risks during the cooling season underscore the importance of adequate shading and ventilation. Ultimately, the study validates the effectiveness of glazed balconies as a passive heating solution in regions with cold heating seasons and highlights the critical role of user behaviour in enhancing building performance. Unfortunately, a lack of awareness about the benefits of this passive approach is leading to the decline of this vernacular technique, which is a key aspect of Northern Portugal’s architectural identity. Consequently, this research seeks to raise awareness about the need to preserve this climate-responsive vernacular strategy and explore how the associated knowledge and benefits can be integrated into modern buildings to foster a regenerative built environment.