PHILADELPHIA—New test scores on efficiency of energy use by commercial property owners in Philadelphia  won them well-above-average grades, according to results released on Thursday. A city ordinance requires commercial landlors to report on energy usage.

With more than 86% of the buildings covered under the ordinance reporting, the owners as a group achieved an average Energy Star score of 64, significantly exceeding the national average score of 50.

The Building Energy Benchmarking Law, passed by the City Council and signed by Philadelphia Mayor Michael Nutter in 2012, requires building owners and operators with more than 50,000 square feet of indoor floor space (or mixed-use buildings where at least 50,000 square feet of indoor space is devoted to commercial use) to report annual energy and water consumption, using the Environmental Protection Agency‘s Energy Star Portfolio Manager. Users that successfully benchmark their buildings receive scores normalized for building size and adjusted for weather and building usage.

The first-year results cover calendar year 2012, which will serve as a baseline for future reporting and results. Of approximately 1,900 eligible buildings in the city, energy usage and water reports were filed for 1,750 of them. That represents 250 million square feet of building space, or 20% of all built space in the city.

“With the Benchmarking Law and our Greenworks plan, we will continue to be a national leader when it comes to energy efficient buildings. The report released today proves we are achieving significant positive outcomes through our hard work and commitment,” says Nutter. “Philadelphia is dedicated to becoming a greener, cleaner, more sustainable city and our Energy Star rating, above the national median, shows that we are succeeding in those goals.”

An EPA report released on April 10 ranked Philadelphia ninth among the top 25 U.S. metropolitan areas with the most Energy Star-certified buildings.