Common Ground

A challenging urban infill benefits from broad expertise and material certainty

By Sean O’Keefe

Nature is an essential part of the human experience. As the universal backdrop of our lives, nature instills a sense of connection to something greater than ourselves, something grander than now— something eternal. As densities of human populations have increased, first cities, and then metropolises have formed. Building ever larger, taller, and deeper, today superblocks and transit corridors fill space and concentrate purpose in cities like Chicago, New York, and Los Angeles. Structure and infrastructure, concrete and steel fill seemingly every space, challenging nature to find a way to fit in. Thankfully, nature is making a comeback.

“Cities have started recognizing the importance of open spaces and the capacity of nature to enhance the quality of urban living,” says Laura Solano, a landscape architect and principal at Michael Van Valkenburgh Associates (MVVA) in Cambridge, MA. Solano has been practicing landscape architecture for 37 years and is a recognized expert in landscape technology and sustainability. “Nature has a willful wildness about it, an unpredictability and when it’s contrasted against the hardness of a city, a harmonic conversation happens.”

Solano has earned a reputation for solving landscape challenges in complex urban contexts through innovative approaches to stormwater management, incorporating sustainable soils and native plants, and the resourceful use of landscape materials. Among the latter, Solano has high praise for an often-unsung hero in her tool kit – molded polystyrene geofoam, used as a lightweight fill beneath landscapes.

“MVVA has been working with geofoam for twenty-five years, using it in places that no one could imagine,” says Solano of the lightweight, rigid foam she regularly incorporates in her work. Molded polystyrene is a cellular plastic material used to produce incredibly strong geofoam blocks, which are easily moved by hand and carved, sculpted, or stacked on site to create dynamic landforms in tight spaces. Atlas Molded Products is one of North America’s largest manufacturers of molded polystyrene and strives to be an asset to designers and an ally to builders. “Topography is essential to crafting a landscape that intuitively guides the user,” continues Solano. “Geofoam allows us to add undulation in landforms built over structures without adding a tremendous volume of weight. Carefully done, the results are natural and beautiful.”

A recent success and brilliant illustration of Solano’s enthusiasm is One Bennett Park, a high-rise residential infill project along the north edge of Chicago’s loop. At 836 feet tall and 69 stories, One Bennett Park is eighth among Chicago’s ten tallest condominium buildings. The building has handsome finishes, an abundance of amenities, and a community green space at its doorstep. Located in the lively Streeterville neighborhood, One Bennett Park represents architectural collaboration at its best. Developers Related Midwest engaged world-renowned design visionaries, Robert A.M. Stern Architects to work with executive architects, GREC Architects of Chicago, and MVVA for the landscape design, each independently contracted.

“Infill properties always have challenges, and that’s where we thrive,” says Dennis DeCapri, a Principal at GREC, who took a leadership role in guiding his firm’s performance on One Bennett Park. GREC excels in the design and management of large complex commercial and residential projects nationally and internationally and welcomed the chance to collaborate with other visionary practitioners. A developer’s ability to leverage existing assets and realize strategic advantages like an adjacent urban park are often key differentiators in congested urban multifamily residential markets. “There is an existing parking structure on the site that was to be maintained, so a portion of the building and the park were designed to be built over the garage. That’s where the geofoam comes in,” remarked DeCapri.

DeCapri noted that before One Bennett Park his exposure to geofoam and molded polystyrene foam insulations had been with conventional applications like retaining soil and insulating a foundation wall, roof, or vertical wall cavity. Seeing the landscape vision proposed by MVVA’s team, DeCapri understood that it was more than just the light weight of geofoam that made Atlas’ product the ideal building material.

“The geofoam was key because this two-acre landscape rises as much as 24 feet above grade in some places,” says DeCapri. “The existing garage has limited loading capacity so significant contouring wouldn’t have been possible if the garage deck had to be loaded with soil.”

Previously the top of the garage was an uninviting collection of sloping surfaces resembling origami; largely the domain of neighborhood dog walkers and loiterers. The reimagined green space adorning One Bennett Park had to be designed to serve both building residents and the surrounding neighborhood.

The new park offers an inviting animated playscape boasting a soft, spongy blue-green play pad with slides built into a hillside. There is a climbing forest, kid cabins, and a walking path winding around a community lawn rimmed by shrubs to subtly provide a sense of enclosure. Beyond, a shady grove of trees contrasts the multipurpose spaces with small, secluded meeting moments tucked along the west edge. Two separately fenced dog runs – large and small – invite public access. Thoughtfully planned breaks in fencing offer neighbors cross-block pass-throughs.

“Neighborhoods are very important in Chicago. Streeterville is a tightknit community. This park had to offer something for everyone: people with dogs, kids, grandkids, or no kids,” continues Solano. “A flat landscape doesn’t inspire; our work is sculptural with lots of topography. The configurations we design can be tricky. We do a grading plans, lots of studies, and often build models before we are satisfied.”

Once the design is understood, configuring a geofoam purchase order to fill the bill can be something of a puzzle in and of itself. In solving these puzzles, landscape architects and contractors around the country find ready, reliable expertise in Atlas Molded Products.

“The geofoam manufacturer is almost always involved in the shop drawings, which is critical to success.” says Solano. “They help with specifying their products and figuring out critical details such as: how joints are handled; how many gripper plates are needed; and how the foam needs to be cut and carved, which is super critical to getting the right forms.”

For One Bennett Park Atlas’ product representatives helped define a comprehensive purchase order that included Atlas Geofoam in two different densities, 15 and 19. Rather than delivering a single load of geofoam, Atlas pre-packaged and marked geofoam pieces into specific area-by-area bundles for easier configuration and installation. During construction, Atlas’ onsite presence helped the contractor’s teams understand the assembly process and details.

“Collaboration is essential to success in design and that includes leveraging the expertise of manufacturers like Atlas Molded Products,” finishes Solano. “Without geofoam, many of our designs on rooftops and over unstable soil conditions wouldn’t be possible. Geofoam is a very hard-working product that is simple to use with a little help and practice. It’s well worth the cost.”

Sean O’Keefe writes design and construction industry stories based on 20 years of experience and a keen interest in the people who make projects happen. He can be reached at sean@sokpr.com.