The Bronx County Courthouse opened its environmentally friendly green roof on Tuesday.

The green roof is made up of small absorbent plants that cover about 10,000 square feet of the facility. The structure conserves energy by recycling the air surrounding the building and lowering the outside temperatures. Although the project cost the city about $230,000, officials say the project will significantly reduce air conditioning and heating costs for the courthouse.

There are 13 other green roofs in the Bronx. However, the newly opened courthouse structure is the first of its kind on a city-owned building. Mayor Michael Bloomberg (R-New York) says he plans to create more green roofs in all five city boroughs.