E.P.A.

Los Angeles and Washington took the top spots in the United States Environmental Protection Agency’s ranking of cities with the most energy efficient buildings.

Los Angeles was the star of the Energy Star rankings, with 293 buildings achieving the E.P.A. designation, according to the Top 25 list released Tuesday. The agency awards the Energy Star label to commercial buildings that rank among the top 25 percent in energy efficiency compared with similar structures.

Washington took second place with 204 Energy Star buildings while San Francisco, which has about 20 percent of the population of Los Angeles, came in third with 173 buildings. Denver and Chicago rounded out the top five.

With 90 Energy Star buildings, New York City ranked 10th, behind Houston, Lakeland, Fla., the Dallas-Fort Worth area and Atlanta.

Detroit came in 15th, just behind Seattle and ahead of cities with decidedly greener reputations like Austin, Tex.

The number of buildings qualifying for the Energy Star award jumped 40 percent from 2008, when the E.P.A. first issued the ranking.

Collectively, the 3,900 buildings that won Energy Star ratings in 2009 cut carbon dioxide emissions by more than 4.7 million metric tons, saving some $900 million in energy costs, according to the E.P.A.

The agency said commercial buildings’ energy consumption accounts for 17 percent of the nation’s greenhouse gas emissions.