I am doing the calculations for the "daylight factor method" for Daylight and Views credit. It is an office floorplate that is roughly 150'x150' with an inner core. The perimeter is all open workstations and hugging the core are private offices and meeting rooms.
Can I include the inner meeting rooms/offices in the calculations given that they have glass demountable paritions? Referencing an earlier comment: "A good rule of thumb for daylighting and the LEED daylighting credit is that usable daylighting reaches back into a space about 1.5 - 2 times the head height of the window." from Jill makes me think that they would have a daylit area of 0 and a daylight factor of 0% considering daylight would never reach this deep into the floor plate.
Please advise if I presume these areas never receive daylight and score them a 0, or do I calculate based on the amount of glass that receivs views and maybe some daylighting from the exterior glazing.
Thanks!
TODD REED
Energy Program SpecialistPA DMVA
LEEDuser Expert
890 thumbs up
August 7, 2013 - 3:10 pm
You mean the prescriptive method? This is CI 2009 which does not have the DF option.
If the glass partitions require the use of tools and staff, then the spaces they enclose would need to be included in your calculations. But you cannot use the prescriptive of the daylight factor method when a borrowed light scenario comes into play. You did not mention your window head height, so its hard to say as to whether those spaces would be impacted. by daylight or not. I doubt they would fall within the depth of the daylight zone, so that would be considered as having 0, their square footage would still be considered in the overall regularly occupied square footage.
The rule of thumb mentioned by Jill is a design rule of thumb. Its to give designers a basis when determining head heights to space depth. In general a south facing space will have an area, 1.5 - 2 times the window head height that may receive a level of daylight illuminance that would be enough for some tasks. Many more factors come into play. It is is just a starting point.