The new measure – called the sunlight beam index – is described, and examples are given for a realistic residential house.
The sunlight beam index (SBI) is determined for a full year on a timestep basis (e.g. 15 minutes) but can be aggregated into monthly or yearly totals. The annual total provides a single measure for: one window; a group of windows; or, all the windows for an entire dwelling. Thus the measure is ideally suited for rating, planning and/or guideline purposes.