Greening the Urban Skyline

New York City

America’s iconic skyscraper gets a retrofit aimed at cutting energy use almost 40 percent.

Forty-three percent of New York City office space was built before 1945. So if the city stands a chance of significantly reducing its carbon footprint, it must begin retrofitting existing buildings. And perhaps there’s no better place to start than with the most iconic of them all—the Empire State Building, which has begun a high-profile $500 million capital-improvement campaign that will slash energy use by 38 percent.

Built in 1931 by Shreve, Lamb, and Harmon, the 102-story tower is a powerful monument to American gumption. Now its owner, Empire State Building Company, has partnered with the Clinton Climate Initiative to turn it into a model of sustainability. With the help of Jones Lang LaSalle, Johnson Controls, and the Rocky Mountain Institute, the team generated more than 60 ideas to increase energy efficiency, which were then whittled down to 17 cost-effective options that offered quick payback, including insulating its 6,514 windows, maximizing daylighting, and upgrading (rather than replacing) its chiller.

As part of the plan, the owner is placing part of the energy-saving onus on tenants, writing sustainability incentives into new leasing agreements and offering advice to those who want to green their spaces. Submeters will allow ten-ants to monitor their own energy use and calculate their carbon footprints. “We know that the real issue in skyscrapers is not the bricks and mortar,” says Rick Cook, whose firm, Cook + Fox Architects, recently completed a LEED Platinum interior for Skanska in the building. “It’s how people work, how they operate their workplace.” —Belinda Lanks

San Francisco

Thirty years of environmental regulations render LEED certification here a mere formality.

When the Transamerica Pyramid received LEED Gold certification last December, Mayor Gavin Newsom crowed, “Today, the most famous building in San Francisco is also one of the most environmentally friendly in the country.” It was a curious case of political posturing—not because the achievement was hollow but rather because so many of the programs the building earned credit for had long been in place.

Around 1980, California began adopting strict building codes, known as Title 24, that mandate energy efficiency. “Over the years, they kept tightening it up,” says Dennis Latta, the construction manager for the Pyramid. “Now the normal solution is just to install motion sensors everywhere.” Around two-thirds of the building’s lights are already controlled by motion sensors, and as the rest of the structure is renovated those spaces will include sensors as well. Early last year, construction was completed on a cogeneration plant that produces 70 percent of the Pyramid’s electricity and took the building off of the city’s utility-steam system, for a savings of some $600,000 a year. Ironically, this hard-core measure didn’t count for LEED points, since it had not been operating for a year at the time of the application.

The chief engineer, Doug Peterson, estimates that the Pyramid was already doing three-quarters of the things it got LEED credit for—the practices simply hadn’t been documented. So why did AEGON, the Dutch insurance company that purchased the building in 1999, push for LEED? “Ownership wanted to be a good corporate citizen,” says the Pyramid’s general manager, Phil Rapoport. “From a practical standpoint, we’re finding more tenants only want to look at LEED-certified buildings.” —Kristi Cameron


An ambitious plan to green the former Sears Tower includes a zero-energy hotel.

Chicago, the birthplace of the skyscraper, may soon see its most recognizable landmark get a green retrofit. An ambitious planned renovation of Willis Tower (formerly and better known as the Sears Tower) will cut energy consumption by about 40 to 45 percent.

Completed in 1973 and designed just before the energy crisis, the building (the tallest in the Western Hemisphere) was a testament to engineering prowess, not energy efficiency. Since then, as tenants, including Sears, moved out, various owners have made gradual energy-saving improvements, upgrading light fixtures and changing the air-handling system to reduce its energy consumption by about 35 percent. In its bid for LEED certification, the building’s current management, U.S. Equities, has introduced electronic recycling, bike sharing, and discounted parking for alternative-fuel vehicles. But in its grandest gesture to date, it has hired the Chicago firm Adrian Smith + Gordon Gill Architecture to produce a wide-ranging program to improve energy efficiency and design a neighboring, net-zero-energy hotel.

The first step in modernizing the tower is upgrading its ’70s-era facade, which leaks cold air in the summer, and warm in the winter. In addition to replacing the 16,000 single-pane windows with double-pane, insulated ones, the Smith and Gill team is considering placing a second skin over the existing curtain wall, which would create a “thermal break,” preventing the metal in the curtain wall from transferring its temperature to the interior of the building.

The plan also calls for halving the electricity used by lighting, elevators, and escalators. A daylighting system that automatically dims illumination when there is adequate light will be installed, and the tower’s 104 elevators and 15 escalators, which carry tenants and visitors up and down 110 floors, will be stripped of their outmoded motor-generator sets and fitted with digital controls.

Smith and Gill estimate that it will take between 25 and 30 years to recoup the $350 million required for a total retrofit. But Sara Beardsley, the project’s architect, says that it’s worth it, since it will give the building “the highest standards of building equipment and technology that will last for the next fifty years.” If all the changes are made, the energy saved will offset the operation of the proposed hotel tower, which could then operate off-grid. But at the moment, the hotel is on hold. The tower’s owners hope to cover part of their investment through public funding, which has yet to come through. So will the Willis plan move forward in its entirety? Unfortunately, it may be about as likely as Chicagoans embracing the tower’s new name. —Belinda Lanks

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