Area definition for roofs

Hi Jens, 

LEEDuser actually provides a definition of "roof area" in their FAQ, and even wtihin the post you made. Any time we type those two words together, the website automatically changes the text color, shows it with a light underline, and if you hover your mouse over the words, you'll see the definition. They define it as "...the area of the uppermost surface of the building which covers the Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view). 

That said, I have always treated the parapets as part of the roof that should be included in the calcs.

Interesting question - before version 4, parapets were sometimes excluded, but now in v4 it's not clear.

In v4, "Applicable roof area excludes roof area covered by mechanical equipment, solar energy panels, skylights, and any other appurtenances."

v4 Glossary: "appurtenance : a built-in, nonstructural portion of a roof system. Examples include skylights, ventilators, mechanical equipment, partitions, and solar energy panels."

Surprisingly, the v4 Glossary has no definition of "roof" or "roof area." Ouch.

In many projects I saw submitted (and approved) in versions 2.2, and 2009 parapet areas were excluded, along with mechanical equipment and other appurtenances as justified by several Interpretations. 

One v2009 Interpretation ID# 1942, the inquiry begins with "Since SSc7.2 roof area calculations exclude skylights, parapets, equipment, paving, and other rooftop surfaces ineligible for EnergyStar consideration..." and then asks about a tensile canopy.

The ruling for interpretation #1942 doesn't address whether parapets should be excluded or not, but does state: "Energy Star defines a roof surface as "the uppermost part of the roof system that is in direct contact with solar radiation,"  and, "The credit's testing standards (Energy Star's Program for Roof Products) focus on systems and/or products that are considered permanent, primary systems whose sole function is to shelter the elements, e.g. rain, snow, wind, etc. from entering the building."

By this, and Emily's advice above, it would be safer to include parapets as roof area. 

This is an example of one of the many "legacy assumptions" (my term) that can make the v4 process very frustrating. Teams that have excluded parapet areas on past projects and had them accepted, could be in for a surprise if a reviewer doesn't agree that parapets can be excluded, as there's nothing in the v4 credit library, glossary, or interpretations that says explicitly you *can* exclude parapets.  

I haven't seen that happen specifically for this credit regarding parapets, but in other v4 credits we've had reviewed.

Ooh, agreed about the "legacy assumptions." That issue is equally (if not more so) frustrating for teams that are not familiar with the requirements from older versions that v4 assumes the readers know. I've come across several other examples in other credits where the v4 guide did not define or clearly explain something that was previously included in v3. New LEED teams are left with a lot of confusion for these items and end up spending additional time trying to figure something out that should otherwise have been very simple to include.