Why some NYC buildings are more efficient than LEED-certified ones

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