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Credit language straight from USGBC
Need to check up on the exact LEED credit language from the LEED Rating System on the fly? LEEDuser includes the verbatim language. Members get:
- Easy access to the official LEED credit language with just a couple of clicks.
- On the jobsite without your bulky LEED Reference Guide? Check up on the credit language details here.
- Credit language content is used by permission of the U.S. Green Building Council.
10 Comments
Surfaces
Is a gravel driveway considered a pervious surface? Do you need to calculate a SRIThe solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100. for this area?
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Mar 15 2010
I don't think a gravel driveway is considered pervious, unless it is specifically engineered and maintained to be so. Typically gravel gets packed hard in road situations and is pretty much impervious.
You would need to include it in your SRIThe solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100. calcs, or use one of the other sustainability criteria (shading?).
Calculating the hardscapes that are shaded
The guide requires that we need to calculate the shaded areas at 10 am, 12 noon and on 3pm on the summer solstice? My question is do we need to calculate on specifically on this day? what if June 21 doesn't fall during our performance period?
And when doing this in order to show the compliance are we required to plot an approved survey or a plot drafted by the team? Please forward your ideas on these problems..Thank you.
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Mar 25 2010
Rashid, the reasons for using June 21st are that A) it's the day of peak insolation in the Northern Hemisphere, and B) picking one date creates a uniform measure for all LEED projects.
This credit is more about calculating compliance of permanently installed features, rather than operating in a certian way during a specific performance period, so it doesn't matter whether June 21 falls during your Performance Period.
To show compliance you need to use an accurate site plan that is consistent with the plans used for other aspects of your project. Does that answer your last question?
RASHID HAMEEN replied Mar 26 2010
yes, Tristan we can show compliance by drafting a plan. The issue came to our mind because the guide has specifically mentioned to do the calculations on solstice.
And the second questions was that the plan to drafted will it has to be approved by a licensed surveyor or will it be sufficient if our team plot the plan?
Thank you...
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Mar 26 2010
Rashid, the LEED Online credit form does not specify that the plan needs to be approved by a licensed surveyor, although having your landscape architect or professional engineer put their stamp on it would not hurt.
According to LEED Online, the following are the requirements for the site plan:
1) It was accurate as of the close of the performance period.
2) All non-roof hardscape areas within the LEED project boundary are highlighted.
3) Each portion of hardscape complying with any strategy in this submittal option is clearly marked and labeled.
Underground Parking
I'm working on a project where about 75% of our parking is located under the building itself. The LEED manual says there is "no SRIThe solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100. requirement for parking that is underground... as long as any exposed parking surface area is 50% or less of the total parking surface area."
Does this mean it is not necessary for us to provide plans documenting surface-level hardscape areas and their associated SRI values? That is, documentation requirements will be satisfied if we supply plans documenting the number and location of the parking spaces?
Thanks!
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Aug 04 2010
You're on track to earn this credit via Option 2. However, the credit language states taht any roof used to cover parking should have an SRIThe solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100. value higher than 29, or be vegetated or covered in solar panels, and there is space on the LEED Online credit form to enter this information. But—it's marked "optional."
If you're purusing SSc7.2, it seems like it would pretty much take care of the documentation needed here.
I would suggest you contact USGBC via LEED Online to ask them to clarify what is required documentation in your case.
Ron Frank replied Aug 17 2010
We have a project in San Francisco where all the parking is underground for the building. Is this acceptable to receive the credit under SS Option 2 Path 4 for Heat Island EffectHeat island effect refers to the absorption of heat by hardscapes, such as dark, nonreflective pavement and buildings, and its radiation to surrounding areas. Particularly in urban areas, other sources may include vehicle exhaust, air-conditioners, and street equipment; reduced airflow from tall buildings and narrow streets exacerbates the effect.-Non Roof?
Jacob Arlein replied Director of Energy Services, Environmental Building Strategies Aug 20 2010
Ron,
Yes this approach should work, and their will be no minimum SRIThe solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100. requirement as long as any exposed parking surface area is 50% or less of the total parking surface area, which is usually the case for most underground parking.
Also, if 100% of the parking is underground, this will earn the project an exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. point as well.
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