I submitted a simulation output for our core and shell building. We included the modeled floor plans with simulation shown on them, tables that show both 9am and 3pm results for each room, and additional table that selected the worst case amount of SF from each room (of the 9am and 3pm results) to show that we were compliant. We received feedback from our Design review that says:
The information entered in the LEED Supplemental Daylight and Views Calculation Spreadsheet does not appear to accurately reflect the results of the daylight simulation model. The simulation output document only indicates the compliant areas for 9 a.m. and 3 p.m. individually, and the lower value has been used as the total compliant area, which is not the correct calculation methodology. Revise the spreadsheet to ensure that only the area that is compliant at BOTH [emphasis added] 9 a.m. and 3 p.m. on September 21st, not at one time or the other and not the average compliant area, has been reported as meeting the daylight requirements. Provide revised output reports from the daylight computer simulations and/or a narrative, as necessary.
The information that I provided was actually the WORST CASE of each - this was summarized in the spreadsheet for them. Do we think they're just ignoring that worst-case information I provided, or do I need to figure out how to model something that shows ONLY the square footages that overlap as being sufficiently daylight at BOTH 9am and 3pm? I was under the impression that the way I calculated (which seems to be the way that is suggested above) was correct, but I could be wrong. Is this a new requirement or am I totally off base?
Kristina Bach
VP of InnovationSustainable Investment Group
151 thumbs up
August 25, 2017 - 9:02 am
Our past projects have always overlayed the two simulations and only claimed the areas that were shaded in both (i.e. those areas that met the requirements at both times). Claiming the smaller value of the two separate simulations doesn't really confirm that you actually would meet the daylight requirements at both times in those same spaces (which is the requirement).
I think the example outlined above in the LEEDuser guidance here (100% at 9am and 50% at 3pm) is a poor choice as it is misleading for how to handle situations exactly like yours (where you don't have 100% compliance at either time).
Anna Bak
Sweco6 thumbs up
August 25, 2017 - 9:13 am
Hannah,
Unfortunately the Reviewer is right.
You need to overlap the results from 9am and 3 pm and claim only the overlapped area.
In extreme case you can have a situation that at 9am - 50 sf meet the requirement, at 3pm 20sf meet the requirement, but when you overlap those two areas you will find that only 10sf meet both requirements and can be claimed in the form.
Hope that helps.
All the best, Anna
TODD REED
Energy Program SpecialistPA DMVA
LEEDuser Expert
890 thumbs up
August 25, 2017 - 9:19 am
Using the worst case is simple way of showing compliance and depending on the results, some reviewers will let it go, especially when the compliant percentage is not close to the minimum. But, as noted, it does not demonstrate the area compliant at both times.
GBD Architects
GBD ArchitectsAugust 25, 2017 - 10:49 am
Hi all,
Thanks so much for the feedback. That all said, do you have a good strategy for overlaying and finding only the SF that meet both times? We used Insight from Autodesk in conjunction with our Revit model. Should this program be able to produce this information, or how did you overlay the compliant times?
Thanks,
Hannah