Daylight Evaluation of Static and Kinetic Horizontal Shading Systems: Experimental Study on Illuminance and Simulation of Visual Comfort

Adaptive façade systems are increasingly used to mitigate glare in daylit spaces; however, their performance is often evaluated using illuminance-based metrics or uncalibrated simulations, limiting the reliability of visual comfort assessment. This study proposes a calibrated experimental–simulation framework for assessing glare reduction achieved by a kinetic horizontal shading system (KSS )under real daylight conditions. The approach integrates reduced-scale physical measurements with Radiance-based simulations using a digitally reconstructed twin of the experimental setup. Two geometrically identical test chambers positioned side-by-side —a static reference chamber and a kinetic chamber equipped with six 0.63 m-deep adaptive fins—were investigated using a 1:20 scale mock-up. Internal illuminance measurements were normalised between chambers, and a sky-scaling procedure was applied to calibrate simulated sky luminance distributions against measured data on an hourly basis. This enabled the use of photometrically validated HDR renderings for glare evaluation. Glare performance was analysed for three representative clear-sky days during periods of maximum solar exposure (11:00–17:00). Visual comfort was assessed using Daylight Glare Probability (DGP), Daylight Glare Index (DGI), and veiling luminance (Lveil). The KSS reduced mean DGP from 0.57 to 0.35 (−38%) and peak glare values by nearly half compared to the static configuration. Veiling luminance was reduced by 73%, confirming a substantial physiological improvement in visual comfort. These results demonstrate that adaptive fin movement effectively suppresses both perceptual and physiological glare during critical daylight hours. The proposed calibrated experimental–simulation workflow offers a robust and transferable methodology for evaluating glare performance of adaptive façade systems under real-world daylight conditions.