I'm working through my first 2009 daylighting calculations using the Prescriptive Method. It seems that in 2.2 we used net square feet of the rooms. Now the 2009 template and Supplemental Calcuation spreadsheet call for gross area. First of all, what do they mean by gross area vs. net? I assume the net area would be the interior wall to wall area of the room. What area would be added to this for gross area?
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David Posada
Integrated Design & LEED SpecialistSERA Architects
LEEDuser Expert
1976 thumbs up
August 20, 2010 - 12:41 pm
I was confused by this, too. I would continue to use net area because I think that's the intent of the credit. The Reference Guide doesn't say anything about "net" or "gross" for this credit, just "floor area" so this is one of those cases where you might say "when in doubt, use what seems right."
Wouldn't hurt to add a note explaining your approach in the credit narrative to give the reviewer a heads up.
Eddy Santosa
Director of SustainabilityDBR Engineering Consultants
376 thumbs up
August 23, 2010 - 11:25 am
I think the intent to bring a consistency among the credits.
Although I agree with David, technically, it must be net area instead of gross. Using gross area for daylight calculation is actually incorrect.
Scott Beckman
Director, Green Code ProGreen Code Pro
8 thumbs up
August 23, 2010 - 5:33 pm
Thanks David and Eddy for your comments. This gets complicated with the new way that LEED Online v3 works since you enter project level information like GSF and that information is then pulled into other credit documentation forms. It seems like an error in the system for this particular credit. I have sent an inquiry to GBCI so I hope to get an official response.
Scott Beckman
Director, Green Code ProGreen Code Pro
8 thumbs up
August 27, 2010 - 10:39 am
It looks like the official take is that we are still supposed to use Net Square Area:
"In regards to your question, we certainly understand how that term can be confusing. As the form relates back to the initial project information forms (as indicated by fields highlighted in yellow), the form is asking for the total simulated daylit square footage of the project's regularly occupied total square footage number (entered in on PIf3). Therefore, you may still enter in the appropriate total net square footage of the regularly occupied areas in PIf3, which would then be reflected correctly in the EQc8.1 form. There is no other additional information that would need to be added to the net square area, although the number must be consistent throughout the project."
So instead of entering Gross Square Area in the Project Information forms, we are supposed to enter Net.
Caroline O'Leary
Architectstudio point253
99 thumbs up
January 12, 2011 - 5:18 pm
I've just received the comments on my first LEED project (inherited mid-submittal from someone who is no longer here) and I suppose inevitably this is one of them. Scott, David, et all...I'm wondering if we should use Net for ALL square footage on PIf3.
We've currently using Gross for the building and regularly occupied spaces in PIf3 and of course Net in IEQc8.1 & 8.2 as requested on the form and/or required by the credit.
Have you successfully been through this yet?
Susann Geithner
PrincipalEmerald Built Environments
1297 thumbs up
January 12, 2011 - 5:57 pm
We have done 4 projects for LEED CS 2009. We always enter the net area in PIf 3. In the first review we had to explain the numbers with drawings and excel spread sheet. In the next project we prepared a narrative and submitted it within the initial review, no problems there.
I have raised the question in regards to all the different area definitions at the Greenbuild in the LEED Update session. I hope they are addressing this, because it's not just this credit. There are regular occupied spaces, occupieable spaces, regular occupied gross area, conditioned spaces, usable area according to BOMA, GSF with and without parking, ...