Advocate Lutheran General Hospital Patient Tower

Challenge

The client was strongly committed to integrating sustainability at every level of the project and maintained aspirations for achieving a high LEED certification. The urban site and the scale and complexity of the patient tower, created tight parameters for achieving the desired performance, which included strict regulations for managing stormwater on site. Newly developed/disturbed areas had to reduce the post-development stormwater discharge rate for the 100-year storm down to the pre-development discharge rate for the 3-year storm. At the time of the project, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) had very little provision for green infrastructure, and they would not qualify subsurface detention to satisfy stormwater permitting requirements, even though underground storage was an accepted method for managing stormwater in adjacent counties.

Solution

The landscape architect and client weighed the stormwater regulations along with their desire for multi-functionality in a tight site envelope. To satisfy MWRD’s requirement, the design had to include traditional above-ground detention, but would use subsurface storage to keep the above-grade areas free of stormwater, thereby making them available for use. The above-ground detention area thus became an opportunity to create a sunken Spiral Garden for mediation in the lowest area of the site. The grade change of 10 ft from the northwest of the hospital patient tower, allowed for a logical, gradual set of retaining walls and rain gardens that form a stormwater treatment and infiltration train. The recessed elevation of the meditation garden/detention basin from the street level provides a sense of separation and enclosure for garden occupants. Since this detention area is secondary to the primary sub-surface stormwater detention system, it rarely holds water and therefore usually remains open as a public space. While solving a “technical” issue, the series of bio-infiltration areas achieved the equally critical objective of creating garden spaces for patients, staff, and the wider community that are seamlessly integrated into the facility. This stormwater system has since become a significant demonstration project for the MWRD and other counties to showcase the benefits of high-capacity, green infrastructure design.

• The stormwater detention system consists of an above-grade stormwater detention area and a sub-surface (30” average depth) stone-base/water reservoir system throughout the site. This dual system meets stormwater regulations while maximizing the usable area of the site by keeping the above-grade areas largely free of stormwater. The redundancy also expands capacity for storage and infiltration.
• The Spiral Garden detention area, which is dry except during heavy rain events, functions as a meditation garden centered around a sculpture of children at play. Located on a busy street corner and next to a bus stop, this garden is slightly lower than street grade both to capture rainwater and to dampen surrounding urban street noise. This location connects the hospital landscape to the surrounding neighborhood.
• The green roof, permeable pavements, and rain gardens on the site collect and infiltrate and/or convey all stormwater to the lower Spiral Garden detention area. All stormwater features, such as rain chains, water runnels, and bioinfiltration terraces are designed for the visible flow of water.
• The 24,610-sf of paved surfaces use permeable pavers to maximize rainwater infiltration, minimize the need for salt during winter, and reduce maintenance costs and related disruptions for pavement maintenance.
• The site planting scheme uses grasses, forbs, shrubs, and perennials, with 31,000 plants installed. A total of 65% native species were used with 45% native to Illinois, and an additional 19 native cultivars. The remaining 35% were non-invasive adapted species. All plants were selected for infiltration and cleansing properties, drought-tolerance, and low maintenance requirements.
• A 6,300-sf Meditation Courtyard Garden, located between the new hospital tower and the existing hospital complex, provides outdoor respite areas for patients, families, and staff. This garden contains five benches and twelve chairs for both solitary contemplation and for conversation. Seating is integrated within “woodland” planting to provide intimacy.
• Adjacent to the Courtyard Garden is a 1,300-sf Children’s Garden, which features a soft-surface play area with a play-sculpture that also functions as a seating element. Pavers within the garden beds invite children to interact with the plants.
• A 1,600-sf, 6-in deep semi-intensive green roof built over a pedestrian link, features sedums, native grasses, sedges, wildflowers, and accent perennials such as red columbine and bluebells. Stormwater runoff from this green roof overflows down rain-chains to planters sited alongside the entry drive for visible rainwater capture. The roof corresponds with the second-floor level of the hospital, and is visible from within the hospital through the glass facade on the west side.
• A 0.5-acre, 4-in deep, extensive built-in-place green roof on top of the new Patient Tower features a range of sedum species, native grasses and wildflowers. Both green roofs are only accessible to maintenance workers.

• The construction cost for the landscape was approximately $2.4 million, with the enhanced stormwater-design features valued at approximately $132,500-$219,500, representing an estimated 5.5-9.1% increase in construction cost over a more traditional landscape.
• Although the hospital does not currently reuse the water that it collects and stores, because of the heavily regulated health industry and standards for water quality, their interest in integrating this strategy into future projects suggest a future savings of approximately $16,040 annually for the same amount of water captured on a similar site. While not a significant cost for a hospital entity, this would be a great savings for a similarly-sized site with a program that would allow for storage and reuse.
• The hospital has experienced a reduction in expensive and time-consuming maintenance, including a reduction in chemical fertilizer application, mowing, weeding, and other maintenance protocols required for typical hospital landscapes. A special contractor is outsourced to conduct seasonal care for the plantings, while other sites at the hospital require frequent mowing, six applications of herbicides annually, and annual aeration of turf. Neither herbicides nor aeration are required for the Patient Tower landscape. Initial cost-savings are estimated to be $2,600 annually.

• The dual stormwater management systems (the above-ground Spiral Garden detention area and below-ground stone-base water reservoir) were designed to meet the stormwater regulations of the MWRD, while increasing the developable area of the site. The oversized, redundant system has the added benefit of providing additional stormwater storage as a climate adaptation measure, which was demonstrated in April 2013 during a series of record-breaking storm events, which temporarily filled the Spiral Garden.
• Permeable pavers on top of a gravel bed were used throughout the project to allow for infiltration. However, because the soils within the project site have high clay content, this system functions as a retention basin rather than for infiltration. A detailed soil analysis would have indicated that infiltration would not be possible without further soil amendments. The de facto retention does provide the benefit of cleaning and cooling the water as it filters through the gravel and serves as passive irrigation as the water then moves slowly through the rain gardens.
• Although the hospital was interested in integrating sustainable features into the project from the beginning, multiple internal stakeholders had to approve the design. The relationship between the architect and the facilities department helped to make the case for sustainability and integrating best practices in stormwater management throughout the project. The landscape architect advanced some of the preferred sustainable features by presenting design concepts. For example, initially hospital stakeholders did not find rain gardens to be visually pleasing or compatible with modern architectural design. But after seeing that a stormwater system could make the landscape more visible and highlights its aesthetic qualities, they were convinced of the opportunities presented by rain gardens.
• While surveys from the hospital staff confirmed attitudes and effects of healing gardens in the hospital ‘workplace’, it should be noted that hospital staff in this location are discouraged from using the garden spaces within the hospital itself (primarily the Meditation Courtyard and Children’s Gardens). This is due to the space limitations of the gardens, and of the primary desire by the hospital to encourage their use by patients and visitors. More than half of the staff survey responses and many anecdotes shared during a lunch-and-learn on healing gardens revealed a strong desire for dedicated outdoor spaces for staff, who could benefit from such gardens within a stressful workplace.

Project Team

Client: Advocate Lutheran General Hospital
Landscape Architect: Conservation Design Forum (now Environmental Consulting & Technology, Inc.)
Design Developer: O’Donnell Wicklund Pigozzi and Peterson, Inc.
Architect: OWP/P (now currently Cannon Design) Architects
Structural Engineer: OWP/P
Structures Electrical Engineer: Dickerson Engineering, Inc.
MEP/FP Engineer: Grumman/Butkus Associates
Civil Engineer: Gewalt Hamilton Associates
Landscape Maintenance: Acorn Landscaping

Role of the Landscape Architect

The landscape architect provided full service design, assessing the needs of specific patient and family populations to create outdoor spaces responsive to the spiritual and psychological needs of the hospital community. The landscape architect also managed construction documents and construction administration, integrating a high-performance landscape into the site of a complex and demanding hospital program.