Contrasting daylight simulation, measurements, and occupant’s perception in a LEED Office building in Arid Climate

Daylight is vital to building occupants as it impacts health and productivity of humans in the indoor environment. No doubt that green building rating systems contribute to the awareness of the significance of daylight in buildings, they enhances the indoor environmental quality by awarding credits to daylight harvesting in buildings. LEED as one of the predominant green building rating systems sets specific daylight criterion, and offers more than one option for project teams to assess and comply with the set criterion; either using manual calculations, using computer simulation (during design), or by daylight measurement (by substantial construction). This article presents a case study of a LEED Gold building in Cairo, Egypt. Within this specific case, three daylight assessment approaches were implemented; Daylight simulation (on design drawings), daylight measurement (after substantial construction), and Post Occupancy Evaluation (POE) (after 9 months of building occupancy). This paper contrasted the results of the assessment methods, this contrast in daylight assessment methods revealed the significance as well as drawbacks of each assessment method compared to the other, and distilled valuable insights about the reliability of each of the available assessment methods