Chicago's Willis (formerly Sears) Tower growing greener

CHICAGO — Growing up in Chicago's southwest suburbs, Sara Beardsley had a view of the city's skyline. Today, she is transforming that skyline, but you won't find her work glorified on a $6 mug or gracing postcards.

Most of her impact is invisible as she attempts to reduce one of the largest carbon footprints in Chicago — that of Willis Tower.

Beardsley, a senior architect at Adrian Smith + Gordon Gill Architecture in Chicago, is managing a $200 million to $300 million project to "green" the tallest building in the Western Hemisphere.

The building was completed as the Sears Tower in 1973, the heyday of energy ignorance.

The skyscraper has single-pane windows that leak around the edges and let in hot air in summer and cold in winter, lights everywhere and inefficient electric heating.

"Each old window is like a car driving around," Beardsley said. "And people don't think of it that way; it's just a window. But I think maybe we need to start thinking about it that way."

Buildings account for about 70 percent of all Chicago emissions, according to the Chicago Climate Action Plan.

If the largest 10 buildings in the Loop were targeted for greening, Beardsley said, it would reduce the energy needs of the Loop by more than 10 percent.

In particular, midcentury buildings can average as much as double the energy load of modern buildings and 10 times that of the newest, most energy-efficient buildings, she said.

Willis Tower uses enough electricity each year to power 9,000 Chicago homes, despite changes over the years that have reduced the energy load to about 1.5 times a new office building.

With a building as enormous as Willis Tower, the floor space of which is equivalent to 16 city blocks, a change in the direction of the sun can mean that when the temperature outside is 5 degrees, air conditioning is being pumped into one part of the building because so much heat is being collected from the sunlight while the side in shadow is being heated.

An experimental green roof (greenery planted on a roof to lower energy costs and offset water runoff) on the 90th floor required metal meshing to prevent sod and plants from blowing away.

"The scale of this is mind numbing," said Nathan Kipnis, principal of Nathan Kipnis Architects, a firm specializing in green and sustainable architecture. Kipnis was one of several curious architects and engineers who attended a presentation about the project (held on the 99th floor).

On its face, Kipnis said, greening a building like Willis is like greening any other building — you look at what goes in and what comes out. But the complicating factors are magnified and the issues are unique.

"Just think of what it takes just to get the food up here," he said.

So far, the only visible sign of what the owners hope to be an environmental model for the world is a pallet of dirt and sedum on the tower's 90th floor roof, the beginnings of a "green roof" so high that only mountain vegetation can grow there.

"As you can see, it's blooming," Beardsley said. "There are actually little lady bugs that come up there on the roof."

In design plans, the "green roof" project would be expanded to the multiple roofs, along with wind turbines and solar panels. But those rooftops would be more symbolic than anything else.

The real energy savings will be culled from the 16,000 windows that will be replaced and from lighting automation and reduction.

The window project is estimated to be enough to cut heating needs by 50 percent and allow for new, smaller mechanical systems with a significantly lower environmental impact.

A plumbing upgrade is expected to reduce water usage by 24 million gallons a year.

"It's enough to power hundreds of homes if you can just get people in Willis Tower to shut off their computers at night," Beardsley said.

All told, the project expects to reduce millions of pounds of carbon-dioxide emissions.

While it is hard to calculate how that would affect the region, the idea is to inspire similar greening projects, Beardsley said, which would lead to fewer coal plants needed to generate electricity for the grid.

The greening project is estimated to take 26 years to pay itself back and create jobs equivalent to that of a new 50-story building project, Beardsley said.

Willis Tower is seeking a combination of public and private financing for its greening project. Its owners are seeking private funding for the hotel.

A spokeswoman for the building's owners, a real-estate investment group, said funding is still being finalized and that she could not provide details.

"By the time it's done, the building won't really look that different," Beardsley said.