Summary

The benefits of green roofs are many: longer roof lifespan, greater sound insulation, reduced heating and cooling system needs, and a cutback in storm water runoff. Green roofs decrease carbon dioxide and increase oxygen in cities, making them cooler in the process and reversing the so-called "urban heat island effect." In short, green roofs are the great green hope of many environmentalists, politicians, and architects interested in more efficient and environmentally aware buildings. From a design standpoint, however, there is less consensus. While some see the roof garden as a visual statement using plants, geometric lines, and sculptural elements, others believe concerns for sustainability should outweigh visual appeal. A green roof that combines aesthetics and mechanics has become the goal of many a landscape architect.

To address this quandary, the American Society of Landscape Architects (ASLA) commissioned renowned landscape architects, Michael Van Valkenburgh Associates in collaboration with the Conservation Design Forum to design a 3,300-square-foot green roof garden for its Washington, D.C. headquarters. In Green Roof Gardens , author Christian Werthmann uses this detailed case study to explain the history, methodology, and design process of green roof garden construction, providing a rich source of inspiration and technical knowledge for anybody interested in this simple solution to many of the environmental challenges we face today.

Library Journal Review

Mention the word green to an architect or builder, and talk turns to environmental awareness, energy conservation, and sustainable design. Green roofs, typically made up of a thin layer of soil planted with a hardy groundcover, are relatively new to the United States but have proven their feasibility in Europe. When the American Society of Landscape Architects (ASLA) decided to retrofit a green roof atop its Washington, DC, brownstone headquarters, it partnered award-winning landscape architects Michael Van Valkenburgh Associates with the Conservation Design Forum. The 3300-square-foot, ecologically sound and graciously inviting gardenlike result now serves as an ASLA green-roof case study and is featured in programs to educate and inspire clients and designers. Author and landscape architect Werthmann (Harvard Univ.) presents an exhaustive rooftop tour in a novel encyclopedia format. Generously illustrated entries span the A to Z of green-roof design and construction, including drainage, erosion, maintenance, and planting. Along with Nigel Dunnett and Noel Kingsbury's Planting Green Roofs and Living Walls and the Earth Pledge Foundation's Green Roofs: Ecological Design and Construction, Werthmann's book is recommended for academic and professional collections.-David Soltesz, Cuyahoga Cty. P.L., Parma, OH (c) Copyright 2010. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.