Dear All,
I have a project that's located in Europe. The buiding will have an accessible roof terrace which will be paved with white concrete pavers. The manufacturer does not offer any documentation with indication of SR or SRI for its products. Therefore, I intend to refer to LEED v.2009 manual which in SSc7.1 lists the following properties for white concrete: emissivity of 0.9, reflectance 0.7 and SRI of 86.
According to LEEV v.4 requirements, initial SRI for a roof material has to be 82. So white concrete default value would exceed this value. However, based on CIR # 10411, which lists a 3-year aged value of white concrete of 0.35, it would not meet the LEED v.4 3-year aged SRI of 64.
At the same time, the LEED requirement for a 3-year SR for a paving material is 0.28. In which case, white concrete would meet it.
Hence, two questions:
1. Is my approach of basing a particular product's SRI values based on the LEED manual and CIR valid?
2. Would the 3-year SR/SRI value be accepted by GBCI given the above?
Thank you!
There is also CIR #10411 which lists initial solar reflectance 0.70 and 3-year solar reflectance of 0.35.
Summer Minchew
Managing PartnerEcoimpact Consulting
LEEDuser Expert
167 thumbs up
October 31, 2017 - 3:00 pm
Max: There are a couple of layers here.
1) In terms of CIR 10411 it is important to note that the materials referenced there are typical SR values for standard nonroof materials. Reporting for this credit must be consistent: SR value for nonroof material and SRI value for roof material. So for example, if a typical nonroof material like pavers are used in a roof application, you will need the SRI value and cannot list or claim a typical SR value as referenced in CIR 10411.
2) Credit language states "Use roofing materials that have an SRI equal to or greater than the values in Table 1. Meet the three-year aged SRI value. If three-year aged value information is not available, use materials that meet the initial SRI value." Three-year aged is preferred but if that information is not available, USGBC will accept initial. You do not need to list both.
3) The LEED reference guide does provide an international tip that may help in your specific case: "Projects outside the U.S. can contact manufacturers directly and ask for SRI information. If manufacturers do not provide this information, the project team can identify a similar material from the Cool Roof Rating Council standard for comparison to show that the project’s material meets the intent of the credit." If that does not work you may have to go the independent testing route.
Max Zayika
2 thumbs up
November 1, 2017 - 9:10 am
Hi, Summer, thank you for your comments!
Regarding 1): Table 1, LEEV v. 2009 manual, SS 7.1, p. 112 gives me values for both SR and SRI. Both CIR 10411 and the LEED 2009 manual list the same SR for white concerete of 0.70. Hence, its SRI value should then be 86. Even though, CIR 10411 mentions only SR values, it is logical that relevant SRI values can also be used. Or am I missing something here?
Regarding 3): Unfortunately, the Cool Roof Rating Council's web site does not list any pavers in its database of certified products. I wonder if I can just find a similar paver from a US manufacturer with an SRI certificate and convince GBCI to accept it.
As an alternative, what if the roof conrete slab gets painted with white paint? Is there a standard as to what kind of paint it has to be, how many layers, etc? Do paint manufacturers also offer SRI values for their products?
Deborah Lucking
Director of SustainabilityFentress Architects
LEEDuser Expert
254 thumbs up
November 1, 2017 - 3:43 pm
If it is white concrete, wouldn't you be able to just use the SRI values in the LEED Reference Manual, for the pavers?
Max Zayika
2 thumbs up
November 2, 2017 - 5:53 am
This is what I am hoping!