The Role of Extensive Green Roofs in Sustainable Development

TLDR

Replacing forests, agricultural fields, and urban lands with impervious surfaces has heightened the need for green space, and vegetated roofs offer stormwater management, energy savings, heat island mitigation, roofing longevity, and aesthetic benefits while creating green industry opportunities. This review aims to evaluate the benefits, plant selection, culture, and adoption barriers of extensive green roofs in the United States, focusing primarily on shallow‑substrate systems. The authors synthesize current knowledge on extensive green roofs, examining ecological and economic advantages, plant choices, cultural practices, and obstacles to widespread implementation.

Abstract

As forests, agricultural fields, and suburban and urban lands are replaced with impervious surfaces resulting from development, the necessity to recover green space is becoming increasingly critical to maintain environmental quality. Vegetated or green roofs are one potential remedy for this problem. Establishing plant material on rooftops provides numerous ecological and economic benefits, including stormwater management, energy conservation, mitigation of the urban heat island effect, and increased longevity of roofing membranes, as well as providing a more aesthetically pleasing environment in which to work and live. Furthermore, the construction and maintenance of green roofs provide business opportunities for nurseries, landscape contractors, irrigation specialists, and other green industry members while addressing the issues of environmental stewardship. This paper is a review of current knowledge regarding the benefits of green roofs, plant selection and culture, and barriers to their acceptance in the United States. Because of building weight restrictions and costs, shallow-substrate extensive roofs are much more common than deeper intensive roofs. Therefore, the focus of this review is primarily on extensive green roofs.