Foliage. Trees are used extensively in green design for shade on concrete parking lots and to keep asphalt heat from radiating back into the atmosphere, says Snider. However, trees can sometimes cause a problem for security and block views. In addition, security may want to use some specific vegetation as a deterrent, but green design emphasizes that plants be native to the area. This may or may not cause a conflict, depending on the region.
In the Southwest, for example, putting cacti around the building would be a good natural security barrier. It would also meet green standards, because the plants are native to the area and do not require additional watering or unusual care. However, in other environments, landscapers concerned with security might want to establish a perimeter with some sturdier plants or bushes that are not native and would require extra irrigation or specialized care, going against the green ideal, says Snider.
Conflicts can also arise between crime prevention through environmental design (CPTED) principles and green design as far as height suggestions of plants and trees, says Howell. “The whole CPTED principle is allowing the person to feel safe in their environment, secure in their environment,” by having clear lines of sight, he explains.
A case in point is the example involving trees at the city hall building mentioned at the beginning of this article. The green design called for trees, but they had a low canopy that blocked the line of sight, as well as the effectiveness of some of the lighting.
Howell solved the problem by cutting some of the lower branches to raise the canopy so that people and surveillance cameras both had unobstructed views and more light could get through below the trees. However, if too much of a canopy is cut on certain trees, you’ll lose the shade and, thus, lose the LEED point, according to Howell.
Moreover, he says, oftentimes for security, “it’s even better just to do a flat concrete sidewalk with bollards and flat hardscapes. And, of course, with LEED, there are more greenscapes and softscapes. There’s a clash.”
Perimeter areas. When the New York Mercantile Exchange (NYMEX) building in Manhattan was retrofitted recently, the designers established a perimeter by creating a “bermed up” earth mass covered with grass, rather than simply ringing the building with bollards and other uninviting structures. But it’s still secure, says Susan Kaplan, director of sustainability for the Battery Park City Authority (BPCA) in New York City, which spearheaded the project. They’ve tested the berms, she says, and “any truck or car would be stopped. It wouldn’t be able to get through.”
BPCA claims construction of the first green residential building in the United States, the Solaire, which was completed in 2000. BPCA now has four completed green buildings, and five more are under construction.
The team also uses innovative seating structures as another alternative to bollards. The seats have been crash tested to ensure that they are powerful enough to serve as a security feature. “It’s a way to make it really just look like it’s a nice place to be, rather than a jail,” says Kaplan.
Another example of maintaining an area’s aesthetics while securing the perimeter is visible around the Museum of Jewish Heritage at the south end of Battery Park City, says Kaplan. Instead of placing bollards at that location, BPCA installed long rectangular fountains to serve the same purpose.
Features Adding Security
Generally, with green design, the question from security’s perspective is whether sustainability measures will increase the property’s risk profile. But there are several areas where the green features actually contribute to enhanced security.
Drainage. Traditional buildings tend to have ample concrete, which impedes natural drainage when it rains. Green design calls for more permeable ground cover, such as the grass berms mentioned earlier. That can provide extra natural drainage in the case of a storm and decrease the chance of flooding, which makes the building more secure.
Setback. The concept of setting a building a good distance back from the road is one that green advocates embrace. That’s a green feature that enhances security, because setbacks reduce a facility’s vulnerability to car bombs. For that reason, a specified setback is a requirement for some federal facilities.
The recently completed Wilkie D. Ferguson, Jr. United States Courthouse in Miami, Florida, for example, includes a large setback. It was a security necessity, and it provides green “opportunities, whether that’s creating public spaces or doing sustainable design areas,” says Frank Giblin, director of the General Services Administration (GSA) Urban Development/Good Neighbor Program.
Such softscape areas can provide groundwater recharge and better drainage, a green side effect that’s especially useful in a setting like Miami. In the case of the courthouse, a large grassy area was created that included a grass sculpture by Maya Lin, designer of the Vietnam Veterans Memorial in Washington, D.C.
The way to approach a project like this, says Giblin, is not to ask whether sustainability or security is the driving force, but rather, to consider “when you’re doing security, can you do it in a sustainable way?”