The Schwab Rehabilitation Hospital, located on the West side of Chicago, chose a green roof as the best solution for providing real life skills practice for its patients and horticultural therapy benefits - without having to leave the security of the hospital. In 2001, Schwab contracted landscape architecture firm Douglas Hills Associates, Inc. to prepare a concept master plan for a therapeutic rooftop park and gardens using an existing 10,000 square foot of rooftop space. But because the hospital was also in the final completion stage of a $23 million, multi-phased building addition/renovation project, this ultimately left little funds available for the green roof. Through activism initiated by the landscape architect, however, a lush garden on Schwab's rooftop was made a reality. The firm discovered special opportunities were available through the City of Chicago's Department of the Environment, which was issuing green roof grants under its Urban Heat Island Reduction Initiative. This initiative supports the utilization, development and expansion of 'green' technologies that will mitigate the urban heat island effect and beautify Chicago. In addition, the firm also offered to underwrite a portion of the grant proposal development because it wanted to see the project come to fruition. Ultimately, the hospital received a $400,000 grant for its rooftop park and construction began in early 2003.

The green roof occupies approximately 50% of the entire roof with an approximate size of 10,000 square feet at a per square foot cost of $60 (including plantings, growing media, Garden Roof® Assembly components down to MM6125® membrane). Eight-to-eighteen inches of growing medium was used in various areas of this project. The mix used for the Schwab Rehabilitation Hospital project was a custom blend based on German FLL standards, consisting of a lightweight expanded clay aggregate, Canadian Sphagnum peat moss, compost, sand, and nutrient supplements. This blend is more like a loamy garden soil in its water holding characteristics. It is good for plants that like well-drained soil to somewhat well drained soil.

The landscape architect wanted to make it feel like a midwestern garden and play up the sense of seasonal interest and variety throughout the year. With this in mind, a sequence of color from spring to summer, summer to fall, fall to winter, and back to spring was created. It was also important to create multiple sensory-stimulation environments, with plants selected for fragrance, texture, and color. Early spring-blooming plants include Irises, Campanula and Flax. In the summer, Daylilies, Cone Flowers and Latria are in bloom. Fall selections include Aster as well as Sumac.

Although Horticulture Therapy is a viable treatment method, finding or recreating the "natural world" in dense urban areas is not a simple task. Schwab is a 125-bed comprehensive physical medicine and rehabilitation facility that helps adult and pediatric patients achieve maximum independence. Therapists that work at Schwab -- occupational therapists, physical therapists, speech/language pathologists, psychologists, recreational therapists - - all use the rooftop garden. The hospital consulted with the Director of Horticultural Services of the Chicago Botanical Gardens, Gene Rothart, who is an expert in horticultural therapy programs. Rothart provided guidance regarding the design of the Schwab rooftop park and gardens as well as outlined various programming aspects with hospital staff and administrators. The goal was for the gardens to be a useful space that is an extension of what can be done within the facility, and offer people places to go outside that are both safe and engaging. Another goal was for it to be a beautiful space that relieves tension and provides the restorative properties of nature. Lastly, the hospital wanted a place that would work well for their staff to conduct special therapy programs, where people could start to heal without feeling like they were being encumbered. Vegetables and herbs have been grown in raised beds as part of the Horticultural Therapy program. Other important features of the green roof design include a waterfall garden, a 60 ft. stream, and ornamental fencing on the existing parapet wall.

The drainage layer, Floradrain® FD25, is comprised of lightweight panels of 100% recycled polyethylene, molded into specially designed retention cups and drainage channels. The design allows for the free drainage of excess water while simultaneously promoting irrigation through capillary action and evaporation into the soil/vegetation level. Following the installation of all components, the planting media was installed along with a drip irrigation system and selective water misters.

The green roof consists of a waterproofing membrane, insulation, and drainage/moisture retention elements, which are part of a Garden Roof® Assembly, all supplied by American Hydrotech, Inc. The seamless waterproofing membrane used for the green roof project, Monolithic Membrane 6125® (MM6125), is a hot fluid-applied, rubberized asphalt. The existing building's five-year-old roof membrane (also MM6125) was enhanced with a second, reinforced application of the material. While still hot, Hydroflex® 30, a fiberglass reinforced, rubberized asphalt protection sheet was embedded into the membrane to complete the waterproofing assembly. The primary components of the Garden Roof contain recycled content; MM6125- EV waterproofing membrane (25% recycled content) and Floradrain drainage/water retention panels (100% recycled, molded polyethylene).

The project is beautifully designed as an area to explore, play, rest and heal surrounded by sweeping drifts of ornamental grasses and a small grove of ornamental shrubs that will remain beautiful and functional year round.