Numbers Crunch

Numbers Crunch

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Last month, one of the major measuring devices of the master plan PlaNYC yielded its first set of data. The Local Law 84 benchmarking ordinance was pegged to a suite of laws operating under the catchier banner of the Greener, Greater Buildings Plan (GGBP). The ordinance required all New York City buildings over 50,000 square feet to report energy consumption. With more than 75 percent compliance, the first report was able to cull information from more than 1.7 billion square feet, making it the largest data collection of its kind for a single jurisdiction.

2010 New York Citywide Co2e Emissions by Sector.
Courtesy City of New York

While a single year’s worth of information isn’t enough to track trends, it does provide a few surprising revelations. For example, one particular finding showed that early 20th-century buildings tend to be more efficient than later generations. The report gives the credit to smaller floor plates, efficient envelopes, and smaller ventilation systems. But the report was careful to make the pro-development observation that the energy “measurement per square foot does not necessarily reflect efficiency in terms of energy per unit of economic activity happening in buildings.”

Despite the very positive participation numbers, there are a few kinks that have yet to be ironed out. The Environmental Protection Agency’s Portfolio Manager, the benchmarking tool used to collect the data, should be able to flag obvious mistakes, like a building square footage entry of zero, but it can’t. Also, building owners often entered square footage based on information they gave to the Department of Finance, meaning they entered square footage for space that had taxable revenue and left out the square footage for space that wasn’t rented.

Nevertheless, spotting mistakes will help fine tune the process for the years to come when the data becomes even richer, and not just because there will be several years of benchmarking under the city’s belt. Other laws in the suite mandate audits and require retrofits. Information from auditors will add detail, such as whether a building has punched windows or a curtain wall. “Within two to three years we’re going to have a really nuanced data set,” said Laurie Kerr, a senior policy advisor to the mayor. “We’ll be able to see if buildings are changing.”

Projected impacts of New York’s greenhouse gas reduction strategies.
Courtesy NYC Mayor’s Office / M.J. Beck Consulting

The U.S. Department of Energy is also working with the city to incorporate the information into a national database. Austin, Seattle, Philadelphia, San Francisco, and Washington, D.C. have all recently adopted benchmarking laws. The data will allow decision makers to compare policy and results.

Buildings that are less than 50,000 square feet may also find their way into the mix. Though Kerr acknowledged that smaller building owners might not have the resources to track data, the city is looking at a less demanding program, perhaps a point-of-sale ordinance rather than an annual requirement.

Though some of the GGBP laws dictate specific retrofits, the main thrust of the suite is to provide building owners with information—as well as tax incentives—to make their buildings more energy efficient, which in the long run will save money. “Information drives change,” Kerr said, repeating a Bloomberg mantra. “Providing building owners with information should cause them to make the right decisions.”