Some of New York City's oldest buildings are more energy efficient than LEED-certified buildings.
Although the recently built 7 World Trade Center trumpets its LEED-Gold rating to lure renters, it isn't as efficient as the Chrysler Building, which was constructed in the 1930s.
While 7 World Trade Center gets an Energy Star score of 74 -- just below the minimum allowed for that certification -- the Chrysler building scores 84, thanks to extensive efficiency upgrades. The Empire State Building has a score of 80.
That's because old structures tend to have thicker walls, fewer windows and less ventilation. They also don't lend themselves to massive data centers that consume lots of electricity.
It's also because of energy consumption by tenants. Tenants at the World Trade Center tend to be more data-crunching oriented with firms like Moody's, whereas nonprofits and other firms that require basic computing tend to occupy highly efficient buildings.
Not all older buildings score well, of course. The MetLife Building, built in 1963, scored 39, and the Seagram Building, built in 1958, scored 3.
Those numbers will change for Seagram, which will soon get extensive energy upgrades.
"Some scores will not be flattering, but identifying buildings with the most opportunity to improve is a big part of driving energy savings," Andrew Burr, a performance expert at the Institute for Market Transformation, told the New York Times. "It does put energy on the radar of real estate consumers."
Next page: More surprising numbers
In 2009, NYC passed a first-in-the-nation law that all privately-owned buildings must measure and report on energy consumption. This is the first year that buildings were required to publicly disclose that data.
Some of the information they must divulge includes energy and water use per square foot (energy intensity), greenhouse gas emissions and Energy Star scores.
Eighty percent of the city's carbon emissions come from heating and cooling buildings. NYC wants to cut by a third of these emissions by 2030 as part of PlaNYC, its sustainablity plan.
The data shows that the biggest buildings -- which constitute 2 percent of the city's one million buildings -- consume 45 percent of the city's energy. If they all reached median levels of energy intensity, the city would cut energy consumption 18 percent and greenhouse gas emissions 20 percent.
Still, NYC buildings generally consume less energy and water than the national average.
Why would LEED-certified buildings score lower?
Not all LEED-certified buildings score lower, such as the Empire State Building, which is both LEED-Gold and Energy Star certified. But some buildings do score lower because LEED covers many green building criteria, not solely energy efficiency.
To get LEED certified, building designers can choose from a raft of environmental features, such as the kinds of materials used, water systems and proximity to public transportation.
But one of the criticisms of LEED is that buildings are rated before tenants move in. Once tenants occupy a space they may leave lights and computers running 24 hours a day, for example.
Read NYC's benchmarking report here.
Photo of Chrysler building provided by Songquan Deng via Shutterstock.com