More than 20,000 Energy Star certified buildings across America helped save more than $2.7 Billion in annual utility bills in 2012 while preventing greenhouse gas emissions equal to emissions from the annual electricity use of more than two million homes, the US Environmental Protection Agency (EPA) announced.The Agency released a list of US metropolitan areas with the most Energy Star certified buildings in 2012, highlighting how owners and managers of commercial buildings are taking action on climate change while delivering real financial savings.Los Angeles, Washington, D.C., Chicago, New York, Atlanta ranked in top five.For the fifth year in a row, Los Angeles held on to first place, with 528 buildings followed by Washington, D.C. with 462 buildings. In third place, with 353 buildings, Chicago has risen through the rankings each year, starting in sixth place in 2008 and increasing the number of buildings certified by an average of 32 percent each year. New York, which recently required its commercial buildings to publicly disclose their energy use, was fourth.Energy use in commercial buildings accounts for 17% of U.S. greenhouse gas emissions at a cost of more than $100 Billion per year.The number of buildings applying for and earning Energy Star certification each year in the US is increasing, EPA said. The cumulative number of Energy Star certified buildings has increased by more than 24% compared to last year, representing more than 3 billion square feet of floorspace nationwide. In 2012 alone, more than 8,200 buildings earned EPA’s Energy Star certification, the Agency added.Launched in 1992 by EPA, Energy Star is a market-based partnership to reduce greenhouse gas emissions through energy efficiency.