Brookfield invested $32 million in the rehab, with an original goal of achieve Gold. The building now features low-emissive glass in the curtain wall combined with chillers for energy efficiency; a heat-recovery enthalpy wheel for increased indoor air quality; floor-to-ceiling windows; and a solar-reflective roof with an 8,000-square-foot green roof.

The enhancements will lead to a 23% decline in energy costs, according to Brookfield. 1225 Connecticut is fully leased, having recently inked a 10-year renewal with the World Bank.

Other Platinum certified buildings in the DC area include Louis Dreyfus Property Group's Lafayette Tower at 801 17th St., NW, which received Platinum level certification in May. The company delivered the 11-story, 237,000 square foot building at the beginning of the year, after tearing down the old building at that address and rebuilding it from the ground up.

In April 2009, the Tower Cos. and Lerner Enterprises received their certification for 2000 Tower Oaks Blvd., a 200,000-square-foot office building in Rockville, MD--the first such designation in the area for a multi-tenant commercial office property.

Another building expected to eventually join this club is Monday Properties' 1812 N. Moore St. Designed to meet Platinum standard, once it is developed it will be a 30-story building with 569,739 square feet of office and 11,020 square feet of retail space.