Materials with high-reflexivity should be cleaned periodically to maintain their reflectance properties. An interval of every two years is usually sufficient. However, this is not a LEED credit requirement.
The square footage of a pitched roof (or a dome) should be determined by calculating the surface area of the roofing material itself, not the area as seen from above.
Yes, if they protrude from the building and serve as a roof surface for conditioned spaces below.
You may exclude it. While pools are not specifically mentioned in LEED Interpretation #10235, GBCI has informed LEEDuser that it would probably count them as an appurtenance and exclude them. This is also supported by LEED Interpretation for SSc7.1, #1412 issued 2/7/2006, that excludes water features.
“Appurtenances” such as these are excluded from the credit. To quote from LEED Interpretation #10235 made on 10/01/2012, “Roof area that consists of functional, usable spaces—such as helipads, recreation courts, and areas covered by equipment, solar panels, and appurtenances—can be exempted from the roof calculations for SSc7.2. Projects are not eligible for SSc7.2 if the exempted spaces encompass the entire roof area.”
If it’s not possible to obtain values from the manufacturer, or a reliable industry source, then getting the material tested in a lab according to ASTM standards is recommended.
You can always simply exclude these materials and submit based on known materials.
Yes, the credit allows for a weighted calculation approach. Many projects in this situation are able to comply. You will need to enter all the roof area that you hope to use to comply. See the calculator in LEEDuser's Documentation Toolkit.
No. LEED Interpretation #1412, issued 2/7/2006 sets the precedent here in stating that "Water features are excluded from the calculation."
According to the LEED Reference Guide, "Hardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios." One could add to this list gravel paths and paved tennis courts. In addition, in LEED Interpretation #10113, USGBC stated that gravel paths and other areas using crusher fines are nonroof hardscape surfaces and should not be excluded from the calculations.
Concrete weathers over time and its SRI value goes down. Washing the concrete periodically during building operation is recommended. This LEED credit allows you to use the higher SRI value if the concrete is new. Old concrete should get a reduced value unless washed.