Urban Green

About benchmarking in NYC

  • Why benchmark?

    The energy used in New York’s buildings is responsible for 70 percent of citywide carbon emissions and costs New Yorkers more than $20 billion every year. Despite this enormous impact and expense, most of this energy use remains mysterious. Unlike our general awareness of the mileage per gallon performance when we buy or operate a car, most building owners and managers do not know whether their buildings are efficient. Tenants are usually even less aware.

    Since you can’t manage what you don’t measure, New York City passed a law that requires all large buildings to annually measure their energy use in a process called “benchmarking”. And to ensure that decision makers, such as building owners and prospective tenants, have access to this energy information, the benchmarking data has been made public via a spreadsheet posted on the web. With the launch of METERED New York, that data is now easier to find and easier to understand.

  • What does New York’s benchmarking law require?

    In 2009, as part of a suit of energy efficiency laws called the Greener, Greater Buildings Plan, New York passed Local Law 84 (LL84) – one of the earliest benchmarking laws in the country and the first to be implemented. This law requires the annual benchmarking of all private buildings larger than 50,000 square feet (about a 50 unit apartment building) and all properties with two or more buildings that combined are larger than 100,000 square feet, with a smaller threshold for city-owned properties; the law does not exempt any property types. The law captures almost 13,000 such private properties and 2350 city owned ones. Together they amount to roughly 2% of New York’s million buildings, but account for over half the overall square footage.

    Local Law 84 requires each building’s benchmarking be completed by May 1 of each year, using an online tool, Portfolio Manager, developed by the US Environmental Protection Agency. The bench-marker enters into the tool information about the building’s energy and water use and information about the building, such as its size, type, and occupancy. From these inputs, the tool generates useful data about the building’s energy performance, such as how much energy it uses per square foot, its carbon emissions, and for many types of buildings, a 1-to-100 score showing how it compares to a database of similar buildings nationally. Local Law 84 requires that, after a year (two years for residential properties), this output data be made available on the web.

    The benchmarking of city properties was first required for 2009 energy use, and the data for years 2010 through 2013 is now publicly available. The benchmarking of private properties was first required for 2010 energy use, and the data for years 2011 through 2013 is now publicly available, except that 2011 data is not available for properties that are primarily residential. Compliance in the private sector has steadily increased, from 75% for 2010 data, to 86% for 2013 data.

    Find out more

  • What are we learning?

    LL84 is helping to bridge the knowledge gap that has hampered energy efficiency by providing crucial energy information to thousands of building owners and managers for the first time. But it also did something else: by requiring so many buildings to benchmark, New York City’s law created a revolution in local energy efficiency data. The database was orders of magnitude larger than prior ones, and unlike the data from voluntary benchmarking, which tends to over-represent the proactive building owners, this one provides a representative sample set.

    This data has provided the first major window on how New York’s buildings – or the buildings in any American city, for that matter – use energy. The results, as published in the City’s three annual reports on the annual reports on benchmarking have been revelatory.

    • There is an extremely wide range in the energy used per square foot by buildings in every sector. For example, multifamily properties in the 5th percentile use 3.3 times the energy per square foot as those in the 95th percentile; for office properties the spread is a factor of seven.

    • This range of energy use suggests that there is considerable room for very cost effective improvements. If all of New York’s large buildings were to become at least as efficient as the current average, energy consumption would be reduced by 18%, and if all buildings were to reach the 75th percentile, energy consumption would be reduced by 31%.

    • Newer is not necessarily better. Median energy use per square foot has not changed too much in multi-family properties built over the past century, except for a modest rise over the past 50 years that peaked in the 70’s. In office buildings the median energy use per square foot has risen considerably over the century, peaking in the 70’s and the 90’s -- although much of this is likely due to greater services provided, such as more fresh air and greater density of occupants.

    • New York’s multifamily properties are the biggest user of energy, however hospitals and supermarkets are far more energy intensive.

  • Is benchmarking helping to save energy?

    It’s probably more a question of how much it saves. New York’s third year of benchmarking showed a significant decrease in energy use per square foot: 13% for office buildings and 12% for multi-families, when viewed in aggregate. However when only the buildings that benchmarked all three years were included, the decrease shrinks considerably, and the impacts of Hurricane Sandy in the third year need to be taken into account; also, how does one isolate the impacts of benchmarking from a host of other federal, state and local policies?

    Still, the broader evidence is promising. In analyzing 35,000 buildings that entered complete data in Portfolio Manager each year from 2008 to 2011, the EPA found an average reduction in weather normalized EUI of 7.0%.


    And in the District of Columbia, which has a mandatory benchmarking law similar to New York’s, buildings that benchmarked every year between 2010 and 2013 reduced their consumption by an average of 9%.


  • What is happening in other cities?

    As of May 2015, eleven American cities and Montgomery County, Md. have passed benchmarking ordinances, similar to New York’s, with Atlanta’s being the most recent. The cities include Atlanta, Austin, Berkeley, Boston, Cambridge, Chicago, Minneapolis, New York City, Philadelphia, San Francisco, and Seattle. Cumulatively these policies impact over 42,000 large properties which encompass over 5.4 billion square feet of space. And many other cities are likely to pass similar ordinances soon. Find out more: http://www.buildingrating.org