Abstract: “Field work measurement in the East room from previous work were found to be 2.28% with a wall to window ratio (WWR) of 50% and a %DF of 1.23% for a modified WWR of 25%. This paper examines the extent of the field work %DF values compared to the %DF values that could be derived for similar cases while using alternative methods. The alternative methods include Building Research Station (BRS) protractors and three other simulation software including ECOTECT, IES and ReLux. Results found that the %DF differences between field work values and the alternative methods were minimal. This proves that the %DF method is still a very reliable method for daylight assessment”

Keywords: Daylight factor %DF, Window to wall ratio (WWR), Building Research Station protractors (BRS), ECOTECT, IES<VE> and ReLux