Chicago’s Rush University Medical Center is an urban complex. More than 170 years worth of construction has been stitched together, spanning about six city blocks that abut one of the world’s busiest highways—the Eisenhower Expressway to the north—and bridge a spur of Chicago’s El system. It’s part of the multi-institution Illinois Medical District west of Chicago’s Loop that also includes the John H. Stroger, Jr. Hospital of Cook County, the University of Illinois Medical Center, and the Jesse Brown VA Medical Center. In 2004, Rush began implementing what it calls its “Transformation” plan and the recent completion of the Perkins+Will (P+W)–designed 14-floor, 304-bed Tower building is its most prominent feature.

When P+W started its work, Rush’s facilities comprised 22 buildings with 4.3 million square feet on 30.5 acres. In 2009, Phase I was completed, including a new material-management and loading dock, a central power plant, parking, and an orthopedic ambulatory building. The new, $654 million, 830,000-square-foot Tower building is composed of three primary architectural elements: an entry pavilion that connects with the existing campus structures; a predominantly orthogonal base that houses an interventional medicine platform, the Center for Advanced Emergency Response, and advanced imaging centers; and the “butterfly”-shaped patient-unit tower whose private rooms provide stunning views of Chicago’s skyline.

Design principal Ralph Johnson, FAIA, and senior design architect John Moorhead, AIA, led P+W’s team with the other firm principals and introduced the hospital to green issues at the start. “Rush warmed up to sustainability,” Moorhead says, “then it became one of their guiding principles.” They began with LEED Silver certification in mind but changed the aim to Gold—a tall order. “There’s only a handful of LEED healthcare buildings at this point,” Moorhead says, “and none at this scale.” Johnson underscores that a hospital is fundamentally “an energy hog”—requiring lots of air changes and using vast quantities of water. “We used the Green Guide for Health Care to connect these issues to good public health,” Moorhead says. “We kept honing the point that LEED points are public-health points.”

Mary B. Gregoire spearheaded many of the sustainable initiatives for Rush’s Transformation program as co-chair of the hospital’s green team standardization group. “Daylight was critical,” Gregoire says—which helped drive the butterfly shape of the patient-room tower. “You need to generate the most perimeter,” Johnson says. He describes it as “a modified cruciform plan.”

The Edward A. Brennan Entry Pavilion links the existing Atrium Building—Rush’s main building until now—and the Tower on both the ground and fourth levels. The soaring ground-floor space includes a terrarium that is open to the sky and helps introduce the visitor to some of the complex’s green aspirations. Atop the four-story pavilion is a publicly accessible roof garden. It takes the form of a glass cloister sheltered from the hustle and bustle of the hospital as well as from the city’s noise.

P+W and Rush developed the concept of “On Stage” and “Off Stage” spaces throughout the building. The “On Stage” areas include all publicly accessible spaces while the “Off Stage” areas are devoted to clinical uses and remain hidden to visitors. This allows for greater efficiency and privacy where it’s needed, but just because an area is “Off Stage,” doesn’t mean it’s any less important. On the interventional medicine levels, where most space is “Off Stage,” the corridors are located along the exterior of the building so that staff can readily step outside an operating room to take a quick break and see natural light and a city view.

What’s not clearly visible are the majority of the building’s sustainable components. The use of recycled building materials were substantial: 27 percent of the concrete and 74 percent of the steel. More than 70 percent of the wood doors come from FSC-certified sustainable forests. The envelope features high-efficiency low-E glass, improved roof insulation (where there are green roofs), and above-grade wall insulation. The HVAC system lowers the energy consumption to 18 percent below ASHRAE 90.1-2004 requirements, and occupancy sensors and a daylight-control system adjust artificial lighting levels within the building as needed. Condensed moisture from the HVAC system is recycled for use in the chiller plant and site irrigation, saving 1.3 million gallons of water per year, while choosing microfiber mops for housecleaning in the existing structures has saved 500,000 gallons of water annually. “We did lots of ‘trialing’ of products,” Gregoire says, “We engaged the users.” Other water-saving measures include low-flow fixtures and dual-flush toilets that reduce water consumption by 30 percent.

Making the building green in practice and in color involved two Chicago-based landscape architects—Hitchcock Design Group and Hoerr Schaudt Landscape Architects—as part of the project team. “We have indigenous plantings throughout the campus,” Gregoire says. The landscape strategy extends to the surrounding streets as well, where Hitchcock designed infiltration planters that help manage stormwater. “We take rainwater off the street,” Johnson says. “It’s a great prototype for street design.”

In many ways, Rush’s new complex is a two-sided design. Its base remains boxy outside and flexible inside while the tower above is organic in external shape and rigidly prescribed within. The expressway façade gives high-speed travelers a visual landmark and its street face welcomes patients with a more pedestrian scale. And the building’s green initiatives are sometimes obvious—specifically in the terrarium, green roofs, and brightly daylit spaces, while the green aspects of the high-recycled content and carefully chosen materials are more muted. For neighbors, staff, and patients—it’s a building that simply works as a very sophisticated piece of 21st-century design and healthcare.

ARCHITECT contributing editor Edward Keegan, AIA, is a Chicago-based architect who complements his independent practice by writing, broadcasting, and teaching on architectural subjects.

Click below for a video from Rush University Medical Center exploring the sustainable attributes of its new Tower: