Capitol Greenroofs,
Arlington, Va.

With over 15 percent of D.C. covered by buildings and another 14 million sq. ft. of additional impervious development proposed in the next 20 years, there is an enormous demand for vegetated roofing systems to help mitigate urban growth pressures. This increased development is expected to increase stormwater runoff by 34 percent and will likely increase the city’s mean annual temperature by two degrees.

Vegetated roofs can provide a significant number of environmental and economic benefits and probably the best way to reduce stormwater runoff and create additional open space. It is estimated that 75 million sq. ft. of rooftops can be immediately retrofitted and, if greened, could reduce citywide runoff by about six percent.

Capitol Greenroofs provides design and construction administration services, prepare cost estimates, landscape-planting plans and generate construction documents and specifications. The firm oversees project installations to ensure quality control, and occasionally provides cost vs. benefit analyses, life cycle cost/energy savings projections and assists in LEED certification.

Gregory Long, RLA, is the design director.

Herrity Building Greenroof Demonstration Garden, Fairfax County Government Center, Fairfax, Va.