It's good to be green

Vegetative roof systems continue to offer benefits to urban areas

With a move toward sustainability in the commercial building and construction sectors, sustainable design is at the forefront of everyone's minds. And the reason is no secret: Sustainably designed projects have a generally lower effect on the environment and offer favorable operating costs long-term. An easy way to incorporate sustainability into a commercial building envelope is to leverage the benefits of a vegetative roof system into the building's design.

The use of vegetative roof systems is not new. During the 1960s, more refined engineered vegetative roof systems were being used on buildings to aid with managing stormwater. Currently, there are about 30 to 35 North American municipalities that provide policies, incentives or regulations related to vegetative roofs. Chicago; Philadelphia; Seattle; Washington, D.C.; and many other large cities have programs in place for the use of vegetative roof systems.

Aside from incentive programs, vegetative roof systems offer numerous benefits for key stakeholders from facility managers and building owners to tenants and visitors. Designers and roofing professionals have many options (built-in-place or modular systems)to fulfill the architects' visions and simultaneously meet municipal building codes. Designers can pursue everything from an extensive, more functional option to an intensive, rooftop garden concept.

All systems provide readily accessible green environments, habitats for birds and insects, and the option for developing new spaces such as playgrounds or chef gardens. Vegetative roof systems can help mitigate the urban heat island effect by covering heat-holding materials from the urban environment and cooling the urban air through evapotranspiration—the process of transferring moisture from the earth to the atmosphere by evaporation of water and transpiration from plants. This creates a cooler air temperature above a roof's surface—a big win on the environmental scale. But what else? Let's explore the most sustainable characteristics of vegetative roof systems and the circumstances surrounding them.