The White House Better Buildings Challenge has saved participants more than $1 billion in just two years, according to a recent review of the program.

More than 250 partners have signed on to the challenge, which calls for a 20 percent energy reduction over 10 years.

The program launched in 2011 and had more than 7,000 buildings participating in 2012. In 2014, that figure more rose to 32,000 buildings, with an energy cost savings of $840 million last year alone.

Last month, the U.S. Department of Energy released the Better Buildings Solution Center, a tool to help organizations find energy-efficiency solutions by topic, building type, location and more. Just as important, there is also information about financing options for efficiency upgrades.

The program has attracted local and state governments, as well as schools and a wide range of corporations. The initial success of the Better Buildings Challenge highlights a larger trend in energy efficiency that is increasingly market-driven, rather than simply government-mandated.

Noesis, a startup that helps finance energy efficiency projects using a shared savings model, counts Ohio as one of the top five states where the firm is doing business. Last year, Ohio put a legislative freeze on the state’s efficiency standard, so it is hardly a current champion of energy efficiency.

But one of Noesis’ key partners, Trane, has a significant presence in Ohio, which has helped drive about 11 percent of the projects Noesis has completed.

“Policy helps, benchmarking helps,” said Josh Duncan, VP of product management at Noesis. “But the access to financing has been more lucrative than any piece of policy.”

Noesis has found that even for the low-hanging fruit, the investment can be substantial.

The average lighting project through Noesis has been over $200,000, and there is an increasing trend to look at other controls that can be embedded during the lighting upgrade.

“That’s an early trend,” said Duncan, but certainly where the market is headed, if this year’s Lightfair International was any indication.

Noesis has found that lighting controls have an average 41 percent rate of return, but building automation and controls have an even higher rate, nearly 44 percent. Lighting, however, accounts for 72 percent of the firm's project portfolio, compared to just 7 percent for building automation or controls.

Duncan expects that to change quickly in coming years with the trend toward bundled projects as contractors and financing institutions get savvier about paybacks for deeper efficiency projects. Buildings control also might not mean a full building energy management system, but rather just some sensors added into the lights.

Financing may be opening up markets, but as Duncan noted, policy does help. California, with some of the strictest efficiency mandates in the nation, is the location of 40 percent of Noesis' projects. Many of the participants in the Better Buildings Challenge are driven by internal sustainability goals, whether they’re corporations or governments.

On a municipal and state scale, energy benchmarking and auditing rules are helping to drive awareness of efficiency and boost local economies -- and not just in the usual coastal locales.

Benchmarking laws are expanding in the Midwest, with Kansas City joining Chicago and Minneapolis earlier this month. The South is getting in on the action as well, with Atlanta becoming the first Southern city to adopt benchmarking earlier this year.

“Atlanta is paving the way for other cities to take advantage of the significant environmental and economic benefits that come with making city skylines more energy efficient,” Melissa Wright, director of the City Energy Project at NRDC, said in a statement. “This ordinance is tailor-made for Atlanta, taking best practices from other cities and refining them to meet local needs.”