Benchmarking is a way for buildings to measure their energy usage and compare their data with other buildings. It also allows buildings to track their own progress over time. New York City's Greener Greater Buildings Plan requires annual benchmarking for commercial spaces larger than 50,000 square feet. In addition, certain buildings are required to submit an energy audit every ten years.
Since buildings are different sizes and shapes, the benchmarking standard is to calculate BTUs of energy per square foot. Benchmarking is most effective when performed regularly, such as annually. This way, an owner can chart the trends of a building's energy use over time. An owner of several buildings will be able to prioritize upgrades for buildings with the lowest benchmarking scores.
Help with the Energy Star Portfolio Manager is now availble by calling the NYC Benchmarking Help Center. This free resource can be accessed by dialing 311 in New York City or (212) 639-9675.
The Help Center is project of the CUNY Institute for Urban Systems Building Performance Lab with support of the Mayor's Office of Long Term Planning and Sustainability, the NYC Department of Buildings, and NYSERDA. Staffed with CUNY students trained in benchmarking, the Help Center is a premier source for information and assistance regarding the US EPA Energy Star Portfolio Manager tool and other issues relating to compliance with Local Law 84.
The US EPA EnergyStar Portfolio Manager makes benchmarking easy for property owners. To benchmark a building, an owner or analyst needs to collect data about the building's energy usage and enter the data into the Portfolio Manager. The necessary data includes the most recent 12 months of energy consumption, which can be pulled together from utility bills or by contacting utility companies.
Certain building factors need to be normalized to obtain an accurate measurement. These factors include occupancy, outdoor climate, operating hours and operating activities of building tenants. Data on these factors must also be collected.
As explained on the EnergyStar website, the following data must be collected for office buildings. This may be only a partial list, depending on specific situations.
Number of workers
Number of personal computers
Percentage of space which requires heating
Percentage of space which requires cooling
Energy meter ID number
Water meter ID number
The Portfolio Manager analyzes a building's efficiency by comparing it to national data from the Commercial Building Energy Consumption Survey. Once the data is calculated, Energy Star can generate a Statement of Energy Performance which can allow owners to benefit from high-efficiency buildings.
Buildings which achieve a rating in the 75th percentile of the national rankings are eligible for certification as Energy Star buildings. An Energy Star certification is a nationally-recognized award for high-performing buildings and will allow property owners to gain publicity for their achievements.
Proof of an efficient building will be appealing to customers, tenants and buyers. It can also help in qualifying the building for a LEED certification. Owners can also benefit from documenting the data in energy service contracts.
US EPA's Energy Star Portfolio Manager
The most widely used tool for benchmarking energy use. Free and fairly easy to use. Contains tutorials.
NYSERDA Benchmarking: Energy Smart Schools Program
A sample benchmarking report from NYSERDA.
Focus on Commercial Real Estate Benchmarking Toolkit
A free, customized, user-friendly Web-based tool that enables commercial building owners and managers to rate their buildings' energy efficiency and carbon footprint relative to peer office buildings in New York City, the State, and across the nation.