Algorithmic energy retrofit model: Parametric optimization of indoor solar insolation

Over the past 50 years, summer temperatures in Banja Luka have risen by about 2°C, with peak values reaching 40.7°C in July. This trend has led to a significant increase in cooling demand in public buildings, particularly in educational facilities, which represent 31.59 % of all public buildings in Bosnia and Herzegovina. Solar irradiation affects the interior comfort through glare, reflection, and overheating. A case study was conducted on an educational facility in Banja Luka using open-source climate data, sky matrices, and wind condition data. Thermal comfort was assessed via the universal thermal climate index (UTCI) during peak occupancy hours (08:00–16:00) in summer using open-source data. Using an algorithmic model, vertical exterior shading elements were defined according to the intensity of solar irradiation. Simulations in Rhinoceros with Grasshopper, Ladybug, and Honeybee analysed indoor solar irradiation with and without shading in an office space. The results indicated that parametrically optimised shading reduced the highest interior temperature, dispersed solar irradiation more evenly, and enhanced thermal comfort by integrating passive cooling solutions.