Sears TowerGreenovations at “The Big Willie,” nee Sears Tower.First the Empire State Building, now Sears Tower: America’s iconic buildings are going green! The press is all abuzz about yesterday’s announcement by the owners of Chicago’s 110-story landmark — North America’s tallest, and the third-tallest in the world — that they will cut energy use 80 percent and water use 40 percent. The $350 million project will include replacing 16,000 single-pane windows; adding green roofs, wind turbines, and solar panels; relandscaping the plazas around the building’s base; and installing energy-saving fixtures in restrooms, elevators, and other bits of the building’s guts. It is expected to create 3,600 jobs, and an educational center on the ground floor will clue the public in to what’s going on.

All of which is very exciting! Except that two years ago, Richard Daley and Bill Clinton announced that they were … greening the Sears Tower! So what happened to that undertaking? I’ve contacted the Clinaton Climate Initiative and Sears Tower folks to find out.

Meanwhile, back to the latest announcement: the owners are also floating the idea of building a luxury hotel adjacent to the tower, which would be powered by the juice created next door. However, they dispelled an earlier notion that they would paint the tower silver or sheath it in a silver skin for energy efficiency and zippiness.

“Our plans are very ambitious,” John Huston of American Landmark Properties told the press. “Our plans to modernize and transform this icon will re-establish Sears Tower as a leader, a pioneer.”

By the time the five-year project is finished, I should note, the tower won’t go by that name — in fact, it’s getting rechristened this summer as the Willis Tower, a nod to new (and apparently beyond-mega-wealthy-and-influential) tenant Willis Group Holdings, a global insurance broker. Already, locals have dubbed the structure “The Big Willie.” Heh heh.

Still, regardless of the name (and the dismantling of yet another piece of my elementary-school education — yeah, Pluto, I’m looking at you), the building will still be whoppin’ big, and its retrofit a model for others.

Architect Adrian Smith, whose firm AS+GG is leading the eco-renovation, told the New York Times, “If we can take care of one building that size, it has a huge impact on society. It is a village in and of itself.”

And Smith’s partner in the firm, Gordon Gill, emphasized the importance of retrofits (yay!): “Sustainable architecture in new buildings is important but not enough to address the climate and energy crises facing our world. We have to apply what we’ve learned to our existing stock of commercial buildings–especially iconic structures such as Sears Tower, which we hope will inspire similar initiatives around the globe.”

Fingers crossed.

UPDATE: A spokeswoman for Sears Tower tells me that building management took steps toward an energy audit after the Clinton announcement in 2007 but did not make any other progress. This time around, they’re committed — and their energy cuts will help the Chicago Climate Action Plan reach its goals.