Tallest U.S. building to get "green" retrofit

CHICAGO (Reuters) - The tallest building in the Western Hemisphere will undergo a $350 million “green” retrofit that its owners said on Wednesday will make the 110-story office tower a beacon for environmentally sound space.

The Sears Tower is shown in this aerial view of Chicago July 6, 2006. REUTERS/Jason Reed

Plans call for the 1,450-foot Sears Tower to reduce its electricity consumption by 80 percent and water usage by 40 percent. It will be renamed the Willis tower later this summer in a deal with new tenant global insurance broker Willis Group Holdings.

To achieve the savings, owner American Landmark Properties and its partners plan to:

- Replace the 1973 tower’s 16,000 tinted single-pane windows and create a “thermal break” between Chicago’s frigid winters and hot summers and the interior.

- Install gas boilers equipped with fuel cells, which generate electricity, heat and cooling.

- Revamp the tower’s 104 elevators and 15 escalators to cut their electricity usage by 40 percent.

- Conserve 24 million gallons of water with new restroom fixtures and “condensation capture.”

- “Harvest daylight” by installing systems that automatically dim lighting based on available natural light.

- Install solar panels to heat water.

- Erect wind turbines on building setbacks, if possible.

- Plant green roofs that will be among the highest in the world to reduce storm runoff and the urban heat island effect.

- Replace granite plazas and walls surrounding the tower with terraced park space, trees, glass storefronts and an interactive digital display.

“We hope to set a benchmark for how high-rise buildings throughout the world can limit their impact on the environment,” said architect Adrian Smith in a statement.

Beyond that, the consortium that owns the tower proposed constructing an adjacent hotel that would qualify for the federal LEED (Leadership in Energy and Environmental Design) designation.

Reporting by Andrew Stern, editing by Jackie Frank