By Bushra Kabir
Illustrations courtesy of Willis Tower
The Willis Tower, Chicago’s 1,451-feet-tall global icon, is creating its own green power generation.
The first building in the United States taller than 100 stories, the Willis, formerly known as Sears Tower, is undergoing a five-year renovation project to become environmentally efficient. The plan includes the construction of a 50-story hotel right beside the tower, which also will be built with the environment in mind.
The transformation is being designed by Chicago-based Adrian Smith and Gordon Gill Architecture. The project will cost $350 million, resulting in 80 percent less electricity consumption. There will be changes involving its exterior walls, mechanical systems, lighting, vertical transportation, water supply, hot water, roofs, operations and maintenance. The most visible changes will be noticed on the roofs of the building, which will consist of gardens, solar panels and wind turbines.
“The changes made and benefits realized through the bold sustainable initiatives at the tower serve as an example that a sustainable future is more than a concept, it is within our reach,” John Huston of American Landmark Properties, who represents the building ownership, said on the Facility Blog of Today’s Facility Manager.
A tremendous amount of energy is used in indoor heating especially for large commercial buildings like the Willis Tower. Therefore, part of the plan is to reduce the amount of heating energy consumed by replacing the 16,000 single-paned windows with double-paned windows that have insulating films in between. The window insulation of the 110-story building will promise cooler summers and warmer winters. The successful completion of this change will result in the usage of 60 percent less heating energy.
These days even in daytime, the lights in most buildings are always on. The new green plan for the Willis Tower will find a more energy-efficient and advanced way to power those lights, and also let in more of the natural daylight so that the electric lights are not needed at all. The installation of solar panels on the roofs will help bring in more of the natural energy to run the mechanical systems in the building and save 40 percent of lighting energy in the process. Just as much water usage will be reduced through water-efficient fixtures that will be included. Even the 104 elevators and five escalators will be upgraded to cut their energy usage by half.
The solar panels will not only be used to supply electric power, but also to provide the hot water for the building. The highest level the solar panels will be situated on is the 90th-floor roof. Along with the solar panels on the roofs, several wind turbines will be added to convert kinetic energy into mechanical energy, which will contribute to the electric supply for the tower. Approximately between 30,000 to 35,000 square feet of gardens will be planted on the rooftops to create green roofs, with the intention of reducing storm-water run-off. The rooftop gardens will also help in improving the insulation of the tower, while creating astonishing viewing areas of the city.
“If we can take care of one building that size, it has a huge impact on society,” said Adrian Smith, partner of Adrian Smith and Gordon Gill Architecture, told The New York Times. “It is a village in and of itself.”
The surroundings of the tower are being altered as well. The granite wall on Adams Street will be replaced by a digital display of news and upcoming or current events. Accompanying that, more trees will be planted around the tower and a landscaped terrace will be built, which will help in the natural filtration of carbon dioxide.
Willis Tower already holds the Leadership in Energy and Environment Design (LEED) rating. The reduction in the annual energy consumption after the five-year-long greening project will be equal to saving five million miles of highway driving, 50,000 barrels of crude oil and 10 million light bulbs. The annual energy consumption saved can provide energy for 2,500 average Chicago homes. Finally, the tower will be sharing its knowledge about the environment and how everyone can help bring green to the city through a public showcasing of its green efforts in the lobby.
"Our plans are very ambitious. Our plans are groundbreaking in many respects" and will "set new standards for the greening of existing buildings," Huston told the Chicago Sun-Times.