Montgomery County Council created two new offices Tuesday to oversee efforts to reduce greenhouse-gas emissions and promote the use of sustainable energy sources in the county.

The county has a broad portfolio of environmental regulations and goals, many of them established by a 2008 working group created by County Executive Isiah Leggett. They include an 80 percent reduction in greenhouse-gas emissions by 2050.

But council members said progress toward the goals needed to be accelerated and the county held more accountable. It voted unanimously to create an Office of Sustainability within the Department of Environmental Protection and an Office of Energy and Sustainability within the county’s Department of General Services.

The estimated annual cost of the new offices is $900,000, mostly for additional staff. The council approved funding as part of the fiscal 2015 budget it passed last month.

It also establishes for the first time the county’s definition of sustainability, adapted from the United Nations and other sources: “the creation and maintenance of conditions under which humans and nature can exist in productive harmony and permit fulfilling the social, economic and other requirements of present and future generations.”

The Office of Sustainability will be charged with tracking the county’s progress toward the 2050 goal. Its duties will also include developing energy-savings plans for all county buildings and identifying ways to encourage homeowners to conduct energy audits. The office will also explore the idea of requiring a “home energy score” to be done prior to the sale of a single-family home.

The general services department, which oversees construction and operation of county facilities, will focus its new office on executing energy-savings goals for government buildings and improving the fuel efficiency of the county vehicle fleet, among other duties.

Council member Roger Berliner (D-Potomac-Bethesda), who sponsored a package of new environmental and clean-energy regulations passed by the council earlier this year, said county need to step up its efforts.

“Make no mistake about it. For the county to reduce greenhouse-gas emissions by 80 percent . . . we’re going to have to a lot more,” he said.