One of the most ambitious efforts to transform city skylines around the globe is nearly invisible. That’s because the changes, aimed at drastically reducing energy consumption and carbon emissions in tall buildings, are happening in places most people never venture–in subterranean boiler rooms, behind radiators, under desks and inside the massive walls of office towers built decades ago. Skyscrapers look modern, but they are among the worst culprits in urban areas when it comes to energy consumption and carbon emission, with outdated heating, cooling and lighting systems. And there are a lot of them–some 3 million in the U.S. alone. “No matter what we do on the new-construction side, it is a fraction of what needs to be done with existing tall buildings,” notes Rick Fedrizzi, CEO of the U.S. Green Building Council, which since 2002 has certified more than 1,000 energy-saving retrofits of existing buildings around the globe. An additional 5,234 retrofits are in the works. The work itself isn’t cutting edge–it’s about doing the basics better–but the savings add up: some 200 million metric tons of carbon would no longer be emitted each year. One of the biggest success stories to date is the Empire State Building, which announced last fall that its new $13 million retrofit would pay for itself within three years, thanks to a 38% reduction in annual energy consumption. The total costs were partially offset by a $2 million grant from New York State. But Tony Malkin, owner of the Art Deco building completed in 1931, also managed to save money with novel ideas like refurbishing the glass in the building’s windows instead of replacing it. Instead of paying $2,500 each to replace the 6,514 windows, Malkin spent $700 each to clean and insulate them. The contractors actually set up a window-refurbishing factory on the building’s fifth floor in order to get the job done in less than six months last year. “The industry said it couldn’t be done,” says Kevin Surace, CEO of Serious Materials. Adds Malkin: “We did everything based on cost-effectiveness.” Most of the upgrades were downright ordinary. Workers recaulked the gaps between the limestone slabs on the building’s facade to prevent heat loss, sprayed foam insulation in holes between the radiator pipes and walls and installed variable-frequency drives in the heating and cooling systems for precise temperature control. “I can’t tell you how many people say, ‘Why not install solar cells or put a little windmill on the roof?’ Because it doesn’t make business sense. It makes much more sense to lower energy use,” says Paul Rode, the project manager at Johnson Controls who oversaw the Empire State Building retrofit.
