Impact of final design on daylight provision

Abstract

Daylight analysis informs design decisions in architectural spaces, yet materials, colours, and furnishings - often chosen later - can significantly impact indoor daylighting. This study assessed these effects in a typical open-plan office in Copenhagen using parametric simulations with Radiance through Honeybee in Grasshopper, complemented by a sensitivity analysis following the Morris method. Various office sizes, window-to-wall ratios, orientations, and interior finishes were analysed for daylight factors (DF), Daylight Autonomy (DA), and Useful Daylight Illuminance (UDI). Results indicated that the visual transmittance of windows, furniture quantity, and partition height notably influenced daylighting, whereas surface reflectance had a lesser impact. The study also revealed complexities in predicting daylighting due to non-linear effects and variable interactions. The study suggests that designers might overestimate daylight in early design phases when spaces are unfurnished, indicating the need to clarify the use of furniture in daylight certification models.