GREEN ROOFS AND THE PEOPLE UNDER THEM

In Business, March-April, 2005, Vol. 27, No. 2, p. 27

As more companies get involved in the business of green roofs, their impact is rapidly improving the quality of urban life.

WITH NEW TECHNOLOGY, green roofs can be put on new or old buildings,” says Drew Becher, associate director of Parks & Recreation in Washington, D.C. who is credited with the greening of Chicago when he worked with Mayor Daly. Latest example of an installation in the nation's capital is at the American Society of Landscape Architects (ASLA) that is collaborating with Conservation Design Forum to design a 3,300 sq ft roof surface.
A green roof is one substantially covered with vegetation that provides economic, environmental and esthetic benefits. They last up to twice as long as conventional roofs, save significantly on heating and cooling costs, insulate for sound, reduce storm water runoff, improve air quality and reduce urban heat island effect while restoring biohabitat. Since the 1970s, green roofs have become part of the European landscape, where there are reported to be more than 100 million sq ft of planted roofs today.
In this country, more companies are getting involved in the business of green roofs. Landscape architects, project managers as well as composters are designing and setting up installations. “It's only fitting that ASLA provide a demonstration project on this sustainable technology that can cure so many ills,” explains Nancy Somerville, executive VP of the ASLA which is working with Michael Van Valkenburgh Associates, Inc. on the design process. “We hope to provide a catalyst for more green roof development.”

RESEARCHERS STUDY WATER QUALITY
According to Bill Hunt, Assistant Professor in North Carolina State University's Biological & Agricultural Engineering Department, much of his teaching, research and outreach has focused on innovative storm water treatment practices such as wetlands, bioretention areas, permeable pavements and - most recently - green roofs.
In 2001, Hunt and a colleague, the late Mike Regans, visited Stuttgart, Germany, to learn about green roofs. After visiting with a few German green roof firms, Regans and Hunt established the first two research green roofs in the Southeast, located in Kinston and Goldsboro, North Carolina. These roofs, along with others added since 2002, have been researched by NCSU faculty for pollutant removal and runoff reduction benefits.
Hunt has collaborated with colleagues at Michigan State University and Pennsylvania State University who are also conducting research on these innovative systems. He views green roofs as one of several tools that designers can use to mitigate storm water runoff.

GREAT VIEWS IN SEATTLE
Lush grass and succulents surround the Council Chamber atop Seattle's new City Hall, creating an evolving garden roofscape as plants change color with the seasons. Directly across, the 12th floor terrace of Seattle's new Justice Center offers views of its own garden roof. “They represent important environmental and sustainability components in the city's new Downtown Civic Campus, a project implemented under the Sustainable Building Policy, as part of the city's Environmental Management plan.” That's how Environmental Design + Construction begins its article called “Sustainability With A View,” which also makes these points:
Life-cycle analysis indicates that green roofs greatly extend the life of the roofs' waterproof membranes by providing protection from ultraviolet degradation, temperature extremes and mechanical damage. Both garden roofs require minimal maintenance and can reduce annual storm water runoff by 50 percent to 75 percent. The Justice Center garden roof is 8,500 sq ft; the City Hall roof is 13,000 sq ft. Green roofs consist of a multilayered waterproofing membrane system supplied by American Hydrotech, Inc. of Chicago. The membrane (Monolithic Membrane 6125) is a hot fluid-applied, rubberized asphalt. Water retention and drainage are provided by Floradrain 40, lightweight panels made of 100 percent recycled polyethylene. A geotextile filter sheet (Systemfilter SF) helps prevent loss of soil, mulch and compost while allowing moisture flow. Soils included mix of pine bark, pumice, compost, sand, peat and nutrients.
About landscape design, Matthew Suhadolnik of SvR Design Company explains: “Flowing, naturalistic patterns have been created using groundcover plants of varying textures and in subtle shades of blue, gray and green.” Adds Marcia West of Gustafson Guthrie Nichol Ltd. “We elected to mingle different textures and colors, so that the roof becomes one integrated carpet of plantings when you look down on it - with squares and patches of different plantings that blend together at the edges.”

EXPERIENCES OF A COMPOST SUPPLIER
ERTH Products of Peachtree City, Georgia is capitalizing on Atlanta's movement towards green roof use. ERTH's history of compost utilization projects positioned them to take a leading role in green roof installations. ERTH initially worked on writing compost specifications for golf course green root zone mixes. Compost research conducted by Clemson and Auburn universities enabled them to get approved for U.S. Golf Association (USGA) root mixes for golf greens. Then ERTH started working with structural soils and obtained a license to produce and sell the CU-Structural Soil/Cornell University Urban Tree Mix.
When green roof work got started in Atlanta, the firm was called in because of its work with engineered soils and soil mixes. It has since installed a number of green roofs in the Atlanta area, including the Arthur Blank Family Foundation Building, which recently became Georgia's first gold certified LEED building (LEED is the Leadership in Energy and Environmental Design green building rating system developed by the U.S. Green Building Council).
The depth of the plant growth media is between two to six inches on extensive green roof systems. The weight specifications for these roofs are 16 to 35 pounds per square foot, so it is important to use a light-weight soil media. “You almost need to be an engineer when designing these types of soil mixes because you are working with so many materials of different sizes, weights and measures,” says Wayne King, Sr., who manages ERTH Products.
“One main benefit from green roofs is quality of life,” King points out. “We're greening the neighborhood, contributing to its livability and aesthetics. At the same time, green roofs can play a critical role in urban storm water management.”
At a green roof conference held in Portland, Oregon last year, it was pointed out that if half of the downtown area in Portland (219 acres) all had green roofs, we'd see an estimated 66 million gallons of water retained annually. At the same time, this would eliminate combined sewer overflows by 17 million gallons, reducing storm water discharges between 11 to 15 percent. You could see that in heavily urbanized areas where there are a lot of rooftops - particularly urban areas challenged by combined sewer overflows that lead to contamination of surface waters - installation of green roofs can play a significant role in the amount of water that can be retained after storm events.

EXCELLENCE AWARDS FOR GREEN ROOF PROJECTS
For 2004, the Green Roofs for Healthy Cities organization named these winners in its “Awards of Excellence”ratings in the following categories:
Intensive Residential - Located on the 19th and 28th floor of the Solaire Building in New York City's Battery Park, two green roofs (5,000 sq ft and 4,800 sq ft) have become an integral part of the low-impact design objectives of this Gold LEED-rated building. Dense strands of bamboo trees were planted in the center to provide a windscreen throughout the year and shade green roof paths and benches.
Intensive Institutional - Two years ago, a 17,250 sq ft “Roofmeadow” was installed on the Oaklyn Branch Library in Evansville, Indiana. The earth sheltered structure blends the roof with the landscape to create a native meadow prairie.
Intensive Industrial/Commercial - Rebuilding Soldier Field in Chicago to restore the prominent park setting has led to approximately 17 acres of reclaimed public waterfront parkland.
Extensive Residential - The Island House is a single family residence on one of the Thousands Islands in the St. Lawrence river between New York State and Ontario. The architects wanted to retain the openness of this agrarian landscape while providing clients with privacy and river views. The green roof is integrated both into the site and the building concept - complementing notion of building roof and ground plane.
Extensive Institutional - Engineered by Roofscapes, Inc., this 6,000 sq ft Roofmeadow green roof was installed on a wellness center in central Pennsylvania - an integral part of a green building. Challenges included: Stabilizing vegetation on a steep slope; Detecting leaks on the sloped surface; and Securing waterproofing at the gapped fascia.
Extensive Industrial/Commercial - Covering 454,000 sq ft atop Ford's truck assembly plant, green roof is a significant component of a 600-acre storm water management system designed by architect William McDonough. Other objectives are habitat establishment at roof level, reduction in ambient temperatures, and protection of roof membrane.
(To review Green Roof Infrastructure Monitor, visit:www.greenroofs.org.)

Copyright 2007, The JG Press, Inc.