CIA reveals (a few) details about its new green roof
The Central Intelligence Agency (CIA) isn’t known for sharing information—usually its activities are kept pretty quiet. However, when it recently constructed a new “green” office complex, the agency was happy to share at least some of the details.
The new campus was built with a goal of achieving certification under the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) rating system. Those goals were realized, with the main office building achieving a Silver rating, and two other buildings on the site meeting the Gold standard.
The many new features have produced a tremendous environmental benefit. Low-flow toilets, waterless urinals, high-efficiency showerheads and the use of native landscaping have resulted in a 40 percent savings in the amount of potable water used. Meanwhile, occupancy sensors and energy-efficient appliances have produced an estimated energy savings of 20 percent in the new building. Also, “low emitting” paints and carpets were specified to improve indoor air quality. There is even preferred parking available at the new CIA campus for those driving fuel-efficient vehicles or carpooling.
However, perhaps the most noticeable—and aesthetically pleasing—environmental component of the project is the 22,000-square-foot green roof that was installed, right out in the open.
Of course, there are still a few small secrets. For starters, the CIA won’t divulge the actual location of the building. “That information is classified. It’s in northern Virginia, and that’s really all we can say,” explains Marie Harf, spokesperson for the CIA.
The three key people involved in the project were Adam Steiner, a landscape architect with Urban Limited of Annandale, Va., the firm that handled the design and layout of the green roof; Joe Illan, the CIA’s chief of facilities and support at the new campus, who oversees maintenance of the green roof; and Valde Kuzdzal with the Peterson Co., who was senior project manager for the building project, representing the landlord during the construction process.
“The design of the building began in 2004, and the first shovel hit the ground in 2005,” explains Kuzdzal. “It was completed in 2007. The shape of the building created a nook between two perpendicular wings. During the initial design phase, it was just open space. We found another need for additional space in that area, but it was only a one-story space. So, as we started to design this one-story space, we quickly realized that the roof would be highly visible from the rest of the five-story building around it, as well as from future buildings that might be built on the campus.”
The CIA requested that something “aesthetically pleasing” be added to the top of the roof, and that’s when the decision was made to add a green roof. Ironically, explains Kuzdzal, the green roof wasn’t eligible for credit as part of the LEED certification because it didn’t involve a sufficient portion of the building’s overall roof surface.
Still, given the aesthetic and environmental benefits, the CIA went forward with a green roof. “We had some limiting factors. We had to provide paver ballast around the perimeter of the roof, so we have a 10-foot-wide paver edge around outside of the roof for access, but the area inside of that was pretty much open for us to play with in terms of design,” explains Steiner. “We initially did three or four different designs of ways, or patterns, in which the green roof could be laid out.”
The design finally selected by the CIA has been affectionately called the “crop circle” pattern, Steiner adds. “It features three circles that overlap, with lines radiating out from those circles. The circles themselves are comprised of 4-foot-wide gravel pathways with aluminum edging. All of the other areas that create the geometric shapes outside of those areas are made up of different mixes and colors of sedum. It’s the equivalent of stained glass, where the different colors are framed by leading.”
The interior of the circles are filled with predominately yellow sedum; the outsides of the circle are mainly a white sedum. “The different colors and shapes really add some interest,” says Steiner. Unlike some green roofs, for example those located on the top of a shopping mall, aesthetics needed to be a key component of this application because the area was highly visible.
The green roof was extensive, but the added weight was minimal compared to traditional roof ballast or other equipment that might have been installed up there, adds Steiner. This meant that no serious structural changes needed to be made to the design of that portion of the building.
The installation of the green roof was handled by Prospect Waterproofing Co., which works throughout the Washington, D.C., area and counts green roofs among its specialties. That firm handled the installation of the roofing as well as landscaping components of the project, and no proprietary green roof system was used. “Using one contractor helped keep the process simple, and it worked very smoothly,” says Kuzdzal.
A lightweight soil mix was used, and—though not counted in the LEED process—Kuzdzal says that the stormwater coming off the roof has been shown to be cleaner, as it is filtered by the green roof.
He adds, “Part of the beauty of the design is that it is largely maintenance-free. There is no irrigation. There’s no need to prune or fertilize the sedum. The only real maintenance is to replace those plantings that might die.”
Illan says even that is rare because the sedum seems to do well in both extreme heat and humidity of the summer in that region, as well as the cold of winter. “Only a few plants died during the last summer, but otherwise the roof did great,” he explains. In fact, the sedum that is closer to the perimeter pavers—where there is higher reflective heat—was found to actually be doing the best.
“I am one of the people who gets to enjoy the roof, because my office overlooks it. I have to admit that it is very relaxing to look out at, especially when I’m a little stressed,” says Illan. “The alternative would have been to be looking at a plain, dull, gray roof. The plants make it beautiful, and people working here really appreciate it.”
Currently, only maintenance workers have access to the green roof, “but it was designed with the idea that, one day, it could be open to people working in the building,” Kuzdzal explains. “The problem we’ve encountered is that people like it so much they are always looking for a way to get out on the roof to see it up close.”
For now, that information is being kept top-secret.
Patrick White is a freelance writer and editor who has covered every aspect of the green industry in the past 13 years. He is based in Middlesex, Vt., and is always on the lookout for unusual stories.