Shapiro explained that the conditions giving rise to the green real estate movement--concerns about climate change, fluctuating energy prices and greater attention to corporate accountability in the post-Enron world--have not disappeared amid the recession. Moreover, sustainable practices can lead to dramatic savings; Shapiro cited the example of his client General Electric, which has saved $110 million in energy costs since greening its factories.

His comments were made in the context of a panel on the market for green leases, one of three discussions that comprised the "Green Building: New Requirements and Incentives" event sponsored by law firm Schulte Roth & Zabel LLP. Ken Rapp, CB Richard Ellis vice chairman, said that market is being driven in part by the younger generation, but added that he sees a split between tenants who make green a top-of-mind priority and those that are mainly concerned with how much the space is going for.

"It's been a learning curve for everyone," said Rapp. Other panelists made it clear that the learning process involves everyone from tenants to landlords to contractors. One developer that got its green education early on was the Durst Organization, which built 4 Times Square as its first green office building in the 1990s.