Construction of the 500,000-square-foot vegetative roof on the new headquarters of the U.S. Coast Guard in Washington, D.C., required coordinating 400,000 individual plants, 2 acres of sedum sod, 3 miles of paver paths, and 10,000 cubic yards of soil.Photo: Bill Willis
U.S. Coast Guard Goes Green With Vegetative Roof
Part 1 of a four-part article on roofing
Maureen Alonso has heard both sides of the discussion that accompanies vegetative roofs. As a landscape program regional horticulturist with the General Services Administration in Washington, D.C., who has managed green roofs, she has had the before-and-after conversations.
Before a green roof goes on an institutional or commercial facility, Alonso hears from maintenance and engineering managers in trying to assess the impact the roofs will have on their buildings and their departments’ workloads.
“One of the first things I will hear is, ‘I didn’t think green roofs required maintenance,’ ” she says. “I’m quick to point out that green roofs all require maintenance. They need to take that into consideration early on. It does increase the maintenance costs of the site, but roofs require maintenance in order to perform.”
The after discussion occurs when building occupants speak their minds.
“I often will have building inhabitants stop me and comment on how much they enjoy the roof and the view from their office space,” Alonso says. “They speak specifically to the wildlife component. People will comment on the birds they see. They say that they enjoy walking down a hallway and taking in the wildlife at the time of the year.”
Rarely have such conversations taken place on a larger scale than when discussing the vegetative roof installed on the new Douglas A. Munro Coast Guard Headquarters Building in Washington, D.C. At 557,000 square feet, it is the nation’s second largest green roof and the third largest in the world. The mammoth task of installing the roof, as well as specifying plants and maintaining the system after installation, provide insights for managers considering green roofs for their facilities.