In one of his last acts as Mayor of New York City, Michael Bloomberg issued one final set of grades – ranked on the old A to F scale from school – to city residential buildings based on their energy efficiency or lack thereof. The targets of this sweeping initiative were the city's condos, co-ops and apartment buildings. But more than just rating these multifamily residences on their power consumption, the Bloomberg administration also released this data to the public, the first time that any city in the country has ever taken such action, according to The New York Times (NYT).

The source reports that three-quarters of the city's carbon dioxide emissions are produced by the heating and cooling systems of these buildings. Although the Bloomberg administration passed a law in 2009 to track energy use by city structures in order to curb future carbon emissions, the legislation only applies to buildings greater than 50,000 square feet. This new measure doles out grades to those properties smaller than what the 2009 law affects. According to Cliff Majersik, the executive director of the Institute for Market Transformation, the public release of this information allows for "a more informed marketplace," that gives new tenants information ahead of time on whether they're moving into energy efficient homes or not.

John Lee, deputy directory of energy efficiency for the mayor's sustainability office, added that the intention of these grades is not to shame building owners but instead spur action into taking greener measures.

"This is not pass or fail," Lee told the source. "This is saying how much energy a building is using per square foot."

Homeowners in Maryland can get an energy audit of their own property conducted by scheduling an appointment with a team of Maryland home inspectors. These professionals can help you identify ways in which your house may be wasting power and unnecessarily driving up utility costs.