BRE BR69 PDF

These two Digests present daylight prediction methods that can be used as a first stage in assessing the visual and energy impacts of window design and the effectiveness of daylight-linked lighting controls (see Digest 272). Part 1 covers the calculation of sky component and externally-reflected component; Part 2 deals with the internally-reflected component and corrections (for glazing, maintenance, etc) to the total daylight factor, and the calculation of average daylight factor.