Randall Children's Hospital

Challenge

The hospital building site was disconnected from the neighboring community by an outdated medical office building and parking garage that visually blocked access to the site. Establishing clear site organization and a welcoming, visible presence for the neighborhood and adjacent arterial streets was one challenge. Another was developing functional and meaningful human-scale landscapes for respite and therapeutic purpose that could also integrate stormwater treatment per local regulations. There was also significant design challenge in meeting the competing goals of providing patients with visual and physical access to nature while at the same time maintaining patient privacy. 

Solution

A redesigned North Gantenbein Avenue includes stormwater management and helps reconnect the hospital campus to the surrounding community by forming a new central circulation spine. A wide pedestrian avenue between the old and new parking garages creates new visual access, directing visitors to the hospital area and linking the campus to Dawson Park to the west. The playful exposure of stormwater and other landscape elements, such as the undulating creative play mounds in the courtyard, help to enrich what could have been a sterile hospital environment and add cheerful experiences for children and families. The competing goals of access to nature and patient privacy were addressed by manipulating plantings and landforms such that they visually block patients’ rooms.

• The hospital design follows the Green Guide for Health Care (GGHC) a metric and checklist based on LEED, but specific to the special needs of medical facilities. The GGHC is widely used and includes design, construction, and future operations of the facility.  The design met minimum requirements for the following credits: site selection, development density and community connectivity, alternative transportation, site development, stormwater design, and connection to the natural world.
• 26,403 sf of new stormwater facilities – including four vegetated swales, six infiltration basins, eight flow-through planters, and two stormfilter catch basins – collect stormwater from 271,000 sf of impervious surfaces. Although flow-control was not required for the project per the City of Portland’s Stormwater Management Manual, facilities are sized to accommodate post-development flow-rates consistent with a 10-year storm event. Stormwater features in the 12,700-sf courtyard garden and 12,000-sf roof terrace garden creatively display the filtration process.
• The irrigation system is controlled by a computer link to real-time weather data to ensure that watering occurs only as needed. The majority of the plantings on the roof garden and in the courtyard planters are watered by drip emitters.
• A new 418-space structured parking facility (48,000-sf footprint) minimizes impervious surfaces compared to surface parking. This reduces the need for over 110,000 sf of surface parking.
• Improvements along N Gantenbein Avenue accommodate its new role as the ‘front door’ to the hospital and enhance its stormwater performance. The redesign of the street incorporates a large median with a central bioretention swale and 5,500 sf of previous pavers.
• The project provides secure bicycle storage facilities for 25% of peak day shift staff, exceeding the GGHC requirement of 3%.
• Rubberized pavers, which match the color and texture of the surrounding concrete pavers, are integrated into the third floor terrace garden for safe child play.
• On the third level terrace, mounds and vegetation adjacent to patient rooms screen views of people occupying the terrace, while allowing light and views of stormwater features and plantings into patient rooms.

• Stormwater on the Randall Children’s Hospital campus is managed with bioretention planters. Nineteen stormwater basins filter and slowly release stormwater into municipal pipes with no pumping or expensive mechanical pollution reduction mechanisms. A cost analysis comparing use of a filtration manhole and stormwater pipe versus installation of 2,400 sf of bioretention planters to treat stormwater runoff from a 48,000-sf garage roof shows an upfront savings of $13,000 in hard costs. Additionally, roughly $900 is saved each year in maintenance costs associated with the manual inspection and cleaning of the manhole filter. Naturalized bioretention planting systems cost between $0.50 and $1 per treated cubic foot of water while traditional sand filter systems range between $3 and $6 per treated cubic foot. Therefore, installing a mechanical treatment system at Randall Children’s Hospital could have cost up to 6 times more than the bioretention system. Extrapolating this analysis across the campus improvements leads to an estimated cost saving of over $4.4 million. Similarly, annual operation costs of the mechanical treatment system are 13 times higher than that of the bioretention planting system, leading to an estimated project-wide annual savings of $650,000. This low-cost, localized solution also saves money ‘downstream’ for the City of Portland due to reduced water volumes and increased stormwater quality being discharged into the municipal system.

• The planting design for the third floor terrace required revisions due to both environmental and social factors. As construction on the building progressed, it became clear that the outdoor terrace was subject to more intense winds and greater reflective sun than was anticipated. The strong winds required the addition of a special wind-resistant mulch. Since the roof terrace is a space open to adults and children, the hospital’s therapy garden director suggested that the designers consider the potential likelihood that children would touch and eat landscape plants. Therefore, the plant palette was revised so that all plants are non-toxic and grow well in sun and wind exposure.
• Stormwater management through green infrastructure facilities was important for achieving the project sustainability goals and satisfying new Portland standards. However, the design of the green infrastructure facilities required revisions due to field conditions. For example, at the stormwater facility between Gantenbein and Vancouver Avenues, the volume and velocity of the water being treated from the parking structure exceeded the expectation of the engineers and landscape architects. This caused erosion of fresh soil and plantings. The installation was revised by lining the bottom of the conveyance swale with river rock and incorporating several check dams to slow the water. This facility was designed with grasses at spaced at 24 inches on center, typical for ornamental installations. To maximize filtration function and to resist soil erosion, the spacing was revised to 12 inches on center at subsequent installations. The stormwater facilities are designed to hold a water depth of 9 inches during a storm event. The bottoms of these facilities were either left un-mulched or mulched with pea gravel to the high water line to avoid the problem of mulch floating to the surface and clogging overflow pipes when the planter is filled with water during a rain event.
• Unit pavers of different types were selected for use on the project at several locations. Achieving clean, well-resolved installations requires careful detail design and coordination that is sometimes hard to anticipate. For example, the construction of sand-set concrete unit pavers that terminate precisely on module can be unrealistic, due to field variations and construction tolerances. As these issues became apparent during construction, additional details were developed to instruct the contractor to avoid ‘slivers’ of pavers at edge conditions. In some cases, this required the use of oversized units that could be field-cut to conform to the condition. Alignment of pavement modules constructed in separate construction phases using multiple bid packages required precision in construction layout by the contractor and good communication between designer and builder. The involvement of the landscape architect in construction observation helped to anticipate and avoid problems as the construction progressed.

Project Team

Owner/Developer: Legacy Health
Architect & Landscape Architect: Zimmer Gunsul Frasca Architects LLP
Structural Engineer: Catena Consulting Engineers
Electrical Engineer: Sparling
Mechanical Engineer: CDi Engineers
Civil Engineer: Harper Houf Peterson Righellis, Inc
Medical Equipment: Medical Equipment Planning, Inc
Acoustic Vibration: Altermatt Associates
Lighting: Candela Signage
Wayfinding: Mayer/Reed
Contractor: Hoffman Construction

Role of the Landscape Architect

The landscape architect was an integral part of the design team, assessing the opportunities and constraints of the campus site and developing site design concepts that supported the overall project goals. The team integrated landscape as an essential program element of the hospital and worked at all scales from campus organization to the detailing of walls, stormwater facilities, pavements and plantings. The landscape architect also maintained an active role during construction observation, working with contractors to ensure design goals were realized.