Previously developed?

Scott, the key are the streets. If streets have been constructed pursuant to a jurisdiction's design standards, then you have "construction...that would typically have required regulatory permitting." If the site with streets is one acre or less, it's all previously developed. Or if the site is larger than one acre, then the portion served by the streets is previously developed.
Eliot

Are there foundations on these structures? Any utilities or infrastructure?

I don't know the answer to this one, but I am curious to see how this is handled.

Michael asks some excellent questions, which are also on my mind. Regina, this is a classic case of "you know it when you see it." My gut reaction is that the land would be developed, as the structures are probably more important than the permits in terms of defining development. But it really will depend on the specifics. Please send your question to USGBC so that an expert reviewer can talk about the specifics of your project with you: http://www.gbci.org/org-nav/contact/Contact-Us/Project-Certification-Que...

So I guess the real key to this is the "red-face test."

Can you get up in a public meeting, with all your credibility on the line, and state that a site has been developed.

Meghan makes a great point, we all know what a developed site looks like, and we know the intent behind the credit language. We want you to knock down the condemned factory that closed up shop in the 50s, and build on that lot rather than tearing up the pristine parkland that is in the same natural state it was in the stone age.