Atlantic Cities

The Closest Look Yet at the Relative Energy Efficiency of Big Buildings

The Closest Look Yet at the Relative Energy Efficiency of Big Buildings
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New York City's largest buildings have as outsized a place in the city's energy use profile as they do in the skyline. Just two percent of New York's properties account for 48 percent of the city's energy use. 

What's a city to do? The Bloomberg administration is doing what it does best: crunching massive amounts of data. On Wednesday, the mayor released the city's second annual benchmarking report [PDF], which analyzes the year-to-year energy and water use of New York's 26,680 largest buildings. 

"It's the first time we've had access to this comparative information," says Melissa Wright, an associate director of the Natural Resources Defense Council’s City Energy Project who has worked in the Bloomberg administration. "For so long it was this hidden information about what the real energy performance was of a set of buildings or individual buildings." 

Since this is only the second comprehensive report, conclusions on year-to-year progress are tentative. But there's still a tremendous amount of never-before-seen information about energy use in New York's buildings, which account for 74 percent of the city's greenhouse gas emissions: 

  • Energy consumption varies enormously, even among similar uses. In office buildings, for example, energy use per square foot can differ between neighboring buildings by a factor of six.
  • Three-quarters of New York's largest buildings are multi-family residential properties, which poses a challenge for sustainability improvements going forward. With high turnover and little sense of individual cost or benefit, will residents and/or landlords embrace changes?  
  • The least-efficient quartile of the city's residential buildings produces about 23 percent of all the greenhouse gases from large buildings in NYC. That's more than all the city's hospitals, banks, warehouses, stores, hotels and universities combined. 
  • The median "ENERGY STAR" score, a comprehensive metric used to rank efficiency of New York buildings, rose from 64 to 67 between 2012 and 2013.

New York isn't the first city to start keeping track of its buildings. Washington D.C. passed a benchmarking law in 2008, and other cities have followed suit, including Austin, San Francisco, Boston, Seattle, Minneapolis, and Philadelphia. But as New York's most recent report is quick to point out, the city's efforts far exceed those of its competitors. With 2.25 billion square feet of space accounted for, New York evaluates about twice as much space as those seven cities combined. 

The idea is to keep a running scorecard of a city's built environment. In part, this helps officials allocate resources efficiently and target buildings with particularly poor performance. The long-term goal in New York is to reduce greenhouse gas emissions by 30 percent by the year 2030. 


This chart measures the median source EUI (energy use intensity — roughly equivalent to energy per square foot per year) across different building types. While special uses like hospitals and hotels score poorly in EUI, their influence is minimal compared to offices and especially to large apartment buildings. Courtesy: University of Pennsylvania/NYC Mayor's Office

But beyond implementing certain sustainability requirements—the city is mandating that buildings upgrade lighting systems, for example—the hope is that the "benchmark" will become a tool for renters, owners and investors. For the first time, residents can access information about their own building's energy efficiency.

Going forward, buying a condo in New York will be like buying a Big Mac: you can see exactly what kind of energy consumption you are getting yourself into. This aspect of the plan has been celebrated by the Institute for Market Transformation, a non-profit that aims to promote the connection between energy efficiency and investment.

Just don't read the massive CO2 outputs of the city's largest buildings as a case against density. New York City's buildings are still slightly more energy-friendly than the national average.

A quick comparison of an apartment complex and a single-family home makes that clear. The landmark El Dorado, whose Art Deco facade rose above Central Park West in 1930, produces about 3,402 MtCO2e each year (metric tons of carbon dioxide equivalent). That may seem like a lot, but the skyscraper contains 216 apartments, which means each apartment produces on average 16 MtCO2 per year. The U.S. EPA estimates that the average single-family home produces 20 MtCO2 per year. 

And as Wright points out, most buildings in New York probably do better. Generally speaking, zip codes with the highest median household incomes and largest floor areas (hello, Central Park West) reported some of the worst energy usage in the city. "You would think people who had the means to make improvements would be doing it," she says. "That's not what we're seeing." 

Top image: Songquan Deng/Shutterstock.com

Henry Grabar is a freelance writer and a former fellow at The Atlantic Cities. He lives in New York. All posts »

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