Balcony design recommendations to enhance daylight, thermal and energy performance of mixed-mode office buildings

The use of balconies in hot climates holds the potential to block direct solar radiation thus reducing energy consumption for cooling and enhancing visual comfort. However, balconies may also diminish daylight availability within the room, thereby affecting occupants’ satisfaction and wellbeing. This study aimed to provide balcony design recommendations through a parametric analysis of various combinations of balcony design parameters (balcony depth, width, location on the façade, and parapet type), along with key building design parameters (façade orientation, floor level, and glazed door width), considering a multi-domain objectives assessment. The results demonstrate that balcony design can effectively enhance visual comfort, thermal performance, and energy efficiency while ensuring optimal daylight availability in office rooms located in subtropical climates. Recommendations for balcony design were tailored to each façade orientation and thoughtfully combined with the glazed door width. One optimal combination, featuring a 3-meter-wide glazed door and a 2-meter-deep balcony, proved beneficial for all façade orientations across all floor levels. However, the choice of parapet type should align with the balcony’s location, which is directly correlated with the room’s depth. The insights gained from this study offer valuable information for building designers, highlighting that balconies should not be designed solely as decorative façade elements or spaces for building services. Furthermore, the cross-analysis method developed in this study can be applied by researchers and designers to their own case studies.