We are pursuing the Option 1 - simulation path. The total regularly occupied area (ROA) reported for the simulation is linked to the PIf3 credit. This represents a challenge when creating the simulation model geometry, as it is difficult to represent the ROA in the model spot on (i.e. due to the model grid setting). We communicated how to represent the area in the best way with the software developer (IES VE), who actually advised us against trying to recreate the geometry with the highest precision possible and recommended focusing on robustness of the model instead.
So here comes a question - is there any allowable difference / tolerance range between the ROA reporeted from the model and in PIf3? (NOTE: this has already been touched on in the last topic below [topic net area vs gross area (simulation) from Jan 12 2016], noting that up to 10% difference in area is allowable. Can you please confirm that?). Thank you in advance
TODD REED
Energy Program SpecialistPA DMVA
LEEDuser Expert
889 thumbs up
April 27, 2016 - 1:26 pm
I do not know of any acceptable range difference that is used by USGBC in regards to the difference between a model and the noted ROA.
But, if daylight sim output report does not show the modeled area, then just complete the daylight and views calculator showing the actual room area and the compliant area. I would only do this if the difference between the ROA and modeled areas would not make a difference in credit achievement. Like, maybe, less than 5% difference.
But if what you are showing does show the modeled area then I would provide a narrative explaining the reason for the difference. As long as its not that great of difference, I do not see any reviewer or USGBC not accepting this. Being honest and up front goes along way showing that you are doing the right thing. There are always issues or stipulations and as long you address them showing that it does not effect credit compliance, there is never an issue.
Anna Korinkova
Grinity s.r.o.83 thumbs up
May 5, 2016 - 10:43 am
Thank you for the answer Todd and sorry for the delayed respond. Just to expand a bit on the question. In the v2009_Daylight and Views Calculator_v06, in the tab Dayligth - the Total Floor Area (column E) - does it have to be filled with area values reported from the dayligting model software (i.e. not from CAD drawings)? And the difference from the PIf3 values can be explained in a narrative, as you suggest (as far as it is within a reasonable level). Or, would that be acceptable to use the CAD drawing area values (as reported in PIf3) in column E instead? (I guess the first option is correct, just checking my understanding)
TODD REED
Energy Program SpecialistPA DMVA
LEEDuser Expert
889 thumbs up
May 5, 2016 - 11:01 am
Column E is what would be the regularly occupied area. This area should be the same as reported in PIF3 and as noted previously, if different, a narrative explanation should be noted. This area should come from the CAD drawings because they are the actual project. I'm not sure how big of difference you have between the CAD drawings and your daylight model, (it should not be that much even in IESV, a few square feet) but like I said previously, if the difference is negligible and does not effect credit achievement or the daylight simulations, just use the CAD areas.
If you were to use the modeled area, then you have to provide a narrative explaining this difference and how it does not effect achievement and sim output. An if you get a reviewer who does not do daylight sims, its hard to say what technical advice you might get.
Anna Korinkova
Grinity s.r.o.83 thumbs up
May 6, 2016 - 9:40 am
Thank you Todd, it is clearer now. We haven't created the actual model yet, I am just trying to clarify as much assumptions / model input conventions / methodology as possible before we start, so we don't have to rebuild it later. So I cannot comment onto by how much the ROA will differ in the model Vs PIf3 at this point. Possibly it will be just a few sf, as you suggest. But in any case, thanks for your comments & help on this.