Washington, D.C. developer JBG Cos. has been was awarded LEED Core and Shell gold-level certification from the U.S. Green Building Council for its landmark building at 300 New Jersey Ave. adjacent to the U.S. Capital.

The structure is a 255,000 sq. ft. addition to the historic 51 Louisiana Avenue office building and was designed by renowned architect Lord Richard Rogers. The building features a new 10-story structure of floor-to-ceiling windows that create an atrium. A central structure supports a triangular flying roof of glass, forming the centerpiece of a remarkable expansion.

The building achieved all 38 points attempted toward LEED certification by targeting green building strategies such as brownfield redevelopment, storm water management treatment, urban heat island reduction, water use reduction and innovation in design.

“The recognition by USGBC is not only a validation of 300 New Jersey Avenue’s commitment to innovation in green technology, but also of the project team’s dedication to creating a sustainable and architecturally dramatic building,” said Kai Reynolds, JBG’s executive development officer.

Sustainable features of the project include:

• Environmentally sound site selection: The building occupies a downtown previously developed urban brownfield site located within walking distance of public transportation.

• Water conservation: The building uses a high-efficiency drip irrigation system. High-efficiency plumbing fixtures are expected to save nearly 33% of water used, or more than 361,725 gallons annually.

• Energy conservation: The building is designed to be 44.5% more efficient than required by code.

Construction waste management: 75% of the building’s construction waste was recycled or salvaged.

• Innovation in design: The building features a combined reflective and green roof system that reduces urban heat island effect while improving stormwater quality.

In addition to 300 New Jersey, JBG’s mixed-use development Twinbrook Station in Rockville, Md. was awarded LEED neighborhood development gold certification in 2008. JBG currently has over 25 LEED registered or certified areas, totaling over nine million sq. ft. of development.