Windy City Sears Tower Windmills go green

Wind turbines, roof gardens and solar panels will join the pair of antennas atop the Sears Tower’s staggered rooftops in Chicago, said building officials who announced on Wednesday that the skyscraper would undergo a $350m green renovation.

The five-year project would reduce the tower’s electricity use by 80% and save 24 million gallons of water a year, building owners and architects said.

Separately, a 50-story, 500-room privately funded luxury hotel with its own green components would be built next to the skyscraper within five years.

Popup Video The environmental upgrades are the latest changes affecting Sears Tower.

“Our plans are very ambitious,” said John Huston of American Landmark Properties, who represents the building ownership. “Our plans to modernise and transform this icon will re-establish Sears Tower as a leader, a pioneer.”

In March, London-based Willis Group Holdings announced that the Sears Tower would be renamed Willis Tower later this summer after the company has moved 500 employees into the building. And construction is under way on the tower’s Skydeck to add four enclosed glass-bottomed balconies.

SKYDECK - “The Ledge”

The green project includes the installation of solar panels on the tower’s 90th floor roof to heat water used in the building. Different types of wind turbines will be positioned on the tower’s tiered roofs and tested for efficiency. And between 30,000 square feet (2,787 square meters) and 35,000 square feet (3,250 square meters) of roof gardens will be planted.

“This endeavour is incredibly important as a role model for others to follow,” architect Adrian Smith said. “We see this as a groundbreaking opportunity.”

Other changes to the 110-storey skyscraper, the tallest building in the United States, include improvements to the 16,000 window pieces along the outside of the tower to save heating energy; mechanical system upgrades; updates to the building’s 104 elevators; an advanced lighting control system and restroom renovations aimed at saving water.

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The building, which already meets Leadership in Energy and Environmental Design (LEED) criteria, will undertake sustainability initiatives above and beyond those used by the United Stated Green Building Council to rate a green building. Modernization strategies, designed by Chicago-based Adrian Smith + Gordon Gill Architecture (AS+GG), include:

• Efficiency improvements to the building’s exterior envelope and windows. The tower has 16,000 single-pane windows. Sustainability plans for the building call for a window replacement and glazing program. Strategies to achieve a thermal break of the curtain wall are also being investigated. These upgrades would achieve savings of up to 50 percent of heating energy.
• Mechanical systems upgrades in the form of new gas boilers that utilize fuel cell technologies, which generate electricity, heating and cooling at as much as 90 percent efficiency. Mechanical upgrades also will include new high-efficiency chillers and upgrades to the distribution system.
• The tower’s 104 high speed elevators and 15 escalators that will be modernized with the latest technology to achieve 40 percent reduction in their energy consumption.
• Water savings that will be realized with conservation initiatives through upgrades to restroom fixtures, condensation recovery systems and water efficient landscaping,which will reduce water usage by 40 percent and save 24 million gallons of water each year.

Lighting that will be upgraded through advanced lighting control systems and daylight
harvesting, an advanced lighting control system that automatically dims lights in tenant
spaces based on the amount of sunlight entering through the windows. Combined,
these upgrades will save up to 40 percent of lighting energy consumption.

Renewable energy like wind and solar, and technologies like green roofs that will be
tested. Wind turbines will be tested to take advantage of the tower’s height and unique
set-back roof areas. Solar hot-water panels will help heat water for the building. Green
roofs that can sustain high- altitude conditions, and that will be among the tallest in the
world, will be tested to reduce storm water runoff, improve insulation, help mitigate the
urban heat island effect, and provide pleasant vistas for tenants overlooking the areas.
“Buildings are the world’s largest contributor to carbon emissions, and therefore the biggest
opportunity to address climate change is to retrofit existing structures,” said Adrian Smith,
partner, AS+GG. “Our goal in the Sears Tower greening project is to create a holistic approach
that integrates high-performance building technologies and design strategies for maximum
energy efficiency. In the process, we hope to set a benchmark for how high-rise buildings
throughout the world can limit their impact on the environment.”

“Sustainable architecture in new buildings is important but not enough to address the climate
and energy crises facing our world,” added Gordon Gill, partner, AS+GG. “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. These will
serve as great examples for building owners and managers and can reposition existing building
stock to be as competitive as most new buildings or even better.”

As an important part of the modernization program, Sears Tower’s plazas and retail spaces will
also undergo changes. A new park at Wacker Drive and Adams Street will be an inviting public
space with landscaping and seating. The Adams Street granite wall will be replaced with an
interactive digital display, glass storefronts, and trees, which will be planted to form a
landscaped terrace that will add a natural filter for carbon dioxide.

In addition to the most significant energy efficiency renovations ever undertaken on an existing
building, another aspect of the transformation is a proposed new, privately funded hotel for the
site at Jackson Boulevard and Wacker Drive. The hotel will be designed for a LEED Gold rating,
and will become one of the most sustainable hotels in Chicago. The hotel will fill a critical need
in the West Loop and provide a much welcomed facility for existing building tenants.

also:
via: http://www.guardian.co.uk/environment/2009/jun/25/sears-towers-chicago-green-renovation