Grounds for Change: Activating Vacant Land

Peggy Notebaert Nature Museum Green Roof

Completed

Tags: architecture, Chicago, education, extensive, greenroof, Illinois, infiltration, intensive, museum, public, wetland

Greenroof systems cover all horizontal surfaces on the roof of this Chicago teaching and learning center.

The Peggy Notebaert Nature Museum is the teaching and learning center associated with the Chicago Academy of Sciences.  It is located just off Lakeshore Drive on Chicago's waterfront in Lincoln Park.  In addition to XXXX exhibits and education programs, the Museum is well-known for its complex green roof installations.  Combining exhibits, promotion and awareness campaign, and practical solutions for urban heat island and stormwater runoff problems, the multi-part green roof showcases several different kinds of rooftop landscapes.

The garden is composed of five greenroofs with attendant interpretive displays.  The greenroofs were designed and completed in two separate phases: the first, a demonstration garden, in 2002; the second, a set of four "extensive green roofs," in 2004.

The demonstration greenroof (2,400 sq. ft.) showcases four types of green roof technology arranged in a zig-zag pattern: wetland, extensive, semi-intensive, and intensive.  Placement and choice of the greenroof types depended in part upon variation in loading capacities--some points on the museum's roof are able to support heavier installations than others.

Extensive greenroofs are thin, light installations built over existing conventional roofs.  Waterproofing layers (Sarnafil 60mL waterproofing membrane in this instance) and shallow frames to hold soil allow plants to grow without damaging the existing building's insulation.  The Museum's demonstration extensive greenroof structure is just 4 inches deep.

Intensive greenroofs require higher loading capacity and more advance planning, since they replace traditional roof surfaces and are designed to accommodate human interaction, larger plants, and even furniture.  Some intensive greenroofs can even support small trees.  The Notebaert Museum's intensive and semi-intensive greenroofs vary in depth from 8 to 10 inches.

Extensive greenroofs cover nearly every other elevated surface, totalling 15,300 square feet over three levels.  Plant heights on these roofs vary from 8 to 18 inches, creating a counterpoint skyline to the city of Chicago.  The extended greenroof system has been further developed through the Green Roof Solutions EcoRoof Assembly, a model roof system.

The Notebaert Museum green roofs is one element in a master plan for the Museum designed by Conservation Design Forum.  The larger project includes bluff vegetation and a wetland garden connected to the roof gardens as part of a full-building recirculating water cycle.  Water filtered by the roof garden, for example, runs down a limestone retaining wall to irrigate bluff vegetation.  The roof features greenroof components and systems by Roofmeadow, Inc.  Roofmeadow's Type III: Savannah and Type IV: Meadow 1 systems were used.  In addition to sedums and native plants appropriate to the two habitats, a number of hardy ornamental plants are featured.

The greenroof project was awarded the Green Roofs for Healthy Cities First National Green Roof Infrastructure Conference Award for a Retrofitted Intensive Green Roof in 2003.  Organized tours offer access to the roof for formal and informal learning experiences.

SOURCES:
Green Roofs & Greenwalls Database.  Accessed online April 10, 2011.
http://www.greenroofs.com/projects/pview.php?id=448

Conservation Design Forum.  Accessed online April 10, 2011.
http://www.cdfinc.com/Project?project_id=31

Peggy Notebaert Nature Museum Green Roof fact sheet.  Conservation Design Forum.  Accessed online April 11, 2011.
http://www.naturemuseum.org/greenroof/CDF.pdf

Green Roof Technology
http://www.greenrooftechnology.com/projects#peggy-notebaert

Learn more at: http://www.naturemuseum.org/