Hi all, I am working on a major renovation of an existing downtown campus building. The entire roof of the building is being redone with white TPO. However, the existing elevator and stair enclosures, that pop up out of the roof, will remain the same not be finished with the white TPO. Can these elevator and stair enclosures be excluded from the roof measures area calculation, listed as mechanical or appurtenances?
Thanks,
emily reese moody
Sustainability Director, Certifications & ComplianceJacobs
LEEDuser Expert
476 thumbs up
October 14, 2022 - 5:06 pm
Hi Julie, sorry for the delay.
In case it's still useful, I believe the pop up areas would need to be included in the total applicable SF and would not be considered mechanical areas or appurtanances.
Julie Baines
Project Pivot1 thumbs up
July 18, 2023 - 8:41 pm
Emily,
What about walkway mats that will be adhered to the TPO? The manufacuturer is telling us they do not need to comply and are not able to provide an SRI value. I am not finding these specifically defined as appurtenances in the reference guide or an Interpretation. Can anyone confirm? My gut says they should be compliant.
emily reese moody
Sustainability Director, Certifications & ComplianceJacobs
LEEDuser Expert
476 thumbs up
July 20, 2023 - 11:01 pm
No, anything that shows in the roof plan and is not one of the qualifying areas named in the Ref Guide has to be included in your calculations. If it doesn't qualify on its own, you may still be able to meet the overall requirements, as this is a weighted calculation, so it will depend on what is on the remainder of the qualifying roof area as well as your site hardscape.
If the manufacturer does not have the info available, the product could be tested for the value. Otherwise, it's just treated as a noncompliant area.
Julie Baines
Project Pivot1 thumbs up
January 3, 2024 - 7:01 pm
Emily,
We have a new question, new project, same credit. We have a white TPO roof on 100% of our roof with 60% of that then covered with a green roof tray system. When I add a value into the "vegetative roof" box in the LEED online calculator, it does not give a weighted value to this number. The table does not even have a spot for this cell, only the Standard Area. Am I supposed to divide by .75 first before adding to the form? We have an adjacent public plaza that is concrete with a few trees but we need the weighted value of that 60% of our roof to get us over the threshold. Techincally, the roof under the tray system is compliant. If I did not include the vegetative roof at all, I get better results. This does not seem correct.
Deborah Lucking
Director of SustainabilityFentress Architects
LEEDuser Expert
258 thumbs up
January 3, 2024 - 7:55 pm
i have always been mystified by the calculations for Total Weighted Area. For my past projects, if the roofs are white TPO (or even light grey) and if there are also vegetated roofs, and if the paved non-roof areas are standard concrete, the Credit would be met. Did you try completing the form withoug assigning weights to any of the area SF?
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
530 thumbs up
January 3, 2024 - 11:04 pm
Enter the actual total area of vegetated roof, the form autocalculates the "divide by 75".
for example, if you enter 100 sf within the 'total area of vegetated roof' box you'll notice that 133.33 of "weighted sum of nonroof and roof measures" gets added to the form below. (100 / 75 = 133.33)
Thumbs WAY up to Deborah's comment, what should be such a simple straight forward calculation is deeply mystified by the online credit template.
I am confused when the credit template states "complete the table for all high reflectance roof materials" above the table; then below the table it states "Materials with a lower SRI will contribute to weighted average". So do we include all surfaces and let the online template calculate compliance or just enter the high reflectance surfaces?
Deborah Lucking
Director of SustainabilityFentress Architects
LEEDuser Expert
258 thumbs up
January 4, 2024 - 11:13 am
@Dave Hubka
I typically list ALL materials, even those with unknown SRIs (use "0"). So far, our projects have met the criteria of total weighted area > total area.
On a different note, we prefer to use light grey rather than bright white TPOs - in many cases the latter presents too much of a glare issue.
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
530 thumbs up
January 4, 2024 - 12:36 pm
Thanks Deborah!! so very helpful!
Julie Baines
Project Pivot1 thumbs up
January 4, 2024 - 1:20 pm
Thank you. I do see now that the vegetative roof is in the weighted sum totals at 133% even though it does not have its own cell in the table. (Super confusing!!) It appears I just needed to talk through it with someone.