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Challenged to activate an undevelopable parcel, Goettsch Partners delivers

By Sean O’Keefe

The City of Chicago lives a legacy of architectural excellence derived from an insistence on pushing boundaries through experimentation and innovation. Long viewed as a design laboratory, Chicago’s unique architectural heritage owes much to the Great Chicago Fire of 1871, which left the decimated city ripe for redevelopment. Chicago has also had the fortune of being home to more than a few 20th Century architectural giants including American-icon Frank Lloyd Wright; father of skyscrapers, Louis Sullivan; and modernist pioneer, Mies van der Rohe.

Famous for what he called “skin and bones” architecture defined by a minimal framework of structural order to achieve open unobstructed space, van der Rohe established his Chicago practice in 1938. Today that practice lives on as Goettsch Partners, a firm more than willing to take on some of the world’s greatest design challenges. Among Chicago’s latest legacy assets, one of Goettsch Partners’ newest additions to the cityscape, 150 North Riverside, stands out as an immediately obvious example of the incredible made possible.

150 North Riverside is located along Chicago’s famous loop on a fantastic site where designing something buildable was considered next-to-impossible,” says Erik Harris, an Associate Principal with Goettsch Partners. Hemmed in by a combination of barriers including the City’s set-back zoning requirements along the Chicago River and a bustling, seven-line Amtrak right of way spanning more than 140-ft, the developable parcel offered only a small sliver land just 55-feet wide upon which to build. “Meeting the challenge of building a cost-effective high-rise on this site came down to delivering the required floorplate area with a 45-foot lease span supported by four-story trusses on either side of the 39-foot-wide core.

While the striking geometry of 150 North Riverside will always make the perched structure remarkable to the passerby, the site’s incredible landscape is an almost equally impressive engineering accomplishment that will likely go largely unnoticed.

“From the hard edge of the building, we were able to secure the Air Rights over the Amtrak right of way,” says Harris. “We decked over it to create two and a half acres of public greenspace that conceals the parking structure, lobby area, and loading dock enclosing about 28% of the site. Though the building is extremely vertical, the site is quite horizontal – both presented equations to solve.”

Filling the horizontal void and creating beneficial pedestrian connections to the urban fabric surrounding 150 North Riverside was a multi-disciplinary effort involving every aspect of civil, structural, and mechanical engineering integrated within the unique landscape. Craig Soncrant, a Principal with Wolff Landscape Architecture led the firm’s work on the project, relishing the challenge.

“Complicated green roofs and innovative plaza design is where we thrive,” says Soncrant, relaying that Wolff had some 21-such projects under construction in 2017 in Chicago alone. Soncrant himself led 15 separate high-rise landscapes last year and believes that providing effective green space for tenants is a must-have amenity in Chicago’s post-recession development. “150 North Riverside is a showstopper, an incredible building with a wonderful investment in city beautification that repositioned an inaccessible, eye-sore site as a convenient pedestrian thoroughfare, entry plaza, and river walk.”

The investment was certainly significant and stretching every dollar to improve pro forma is rarely a waste of time. Goettsch Partners originally planned to employ hollowed slab-on void construction to build-up the site topography, but when value engineering analysis revealed the complexities of that much site concrete was cost-prohibitive a new solution was sought. Wolff Landscape Architecture’s experience with an alternative, lightweight, structural-fill was extensive, and Soncrant proposed Geofoam as a very workable surface substrate substitute.  

“EPS Geofoam has been a go-to product in our designs for many years,” says Soncrant. “We use it whenever we need a light, strong, durable material to fill voids and make architecturally-contoured surfaces.” Bringing the design strategy to Goettsch Partners meant providing examples of previous Chicago-area, decked plazas successfully built with Geofoam and introducing the design team to ACH Foam Technologies.

“We only work with materials that we know will perform,” says Harris regarding the Geofoam value engineering proposition. “Performance, in this case, means supporting the pounding it will take from heavy pedestrian use in Chicago’s harsh weather; being easier, faster, and less expensive to work with; and, most importantly, feeling confident in the material’s capacity to meet loading requirements.” Wolff Landscape Architecture’s previous projects with ACH Foam Technologies have included a lightweight rooftop amenity deck on the eleventh floor of Chicago’s Prudential Plaza and at 222 South Riverside Plaza Renovation, also located over railroad tracks and along the Chicago River. Geofoam has also solved technical challenges beneath highways, bridge embankments, levees, and other large civil infrastructure applications where loading requirements are substantially greater than anything required by 150 North Riverside.

Developing a pedestrian-friendly site solution meant responding to elevations as low as the river and as high as the roof of the parking structure, a transition of some 15 vertical feet. Animating the long, horizontal site meant creating a multi-level green space connecting 150 North Riverside and the parking structure immediately to greater Chicago in many different directions.

“Building with Foam-Control Geofoam allowed us to create a two-tier park system that addresses vertical movement on site through a combination of ramps and stairs,” continues Soncrant. Since single blocks of Geofoam can be large enough to fill sections eight-feet long by four-feet deep, they make building multi-level terraces, ramps, stairwells, and planter boxes easy. As importantly, working with Geofoam enables designers to create a custom contour of substrate material in the exact depth need below specific panting areas. Since a tree may need a soil depth of several feet, a shrub some 18 inches, and grass just 6 inches, building a Geofoam base that accommodates appropriate soil depths decreases the overall dead load on the structure and supports controlled, positive drainage across the site.

The task of installing the overall landscape and the Foam-Control Geofoam blocks was won by Twin Oaks Landscaping, Inc. a Chicago-area firm with a national practice dating back to 1983. Steve Jungermann was the man responsible for overseeing the firm’s efforts.

“The project was a challenge simply because of where it’s located,” says Jungermann in relation to the complexity of the surrounding cityscape and the site’s abundance of elevation changes. “On something as complicated as this it’s imperative to get expert guidance.”

Jungermann details the challenges of developing material Take-offs that account for the quantities of Geofoam required to respond to the site’s many grade changes, soil depth-profiles, and architectural contours. Working with ACH Foam Technologies’ product representative Twin Oaks was able to develop an accurate purchase order and devise a finely-tuned delivery sequence for the material. With limited lay-down space and intense coordination required between site work, electrical, plumbing, and landscape construction, maintaining constant communication and just the right amount and types of Geofoam on hand was critical. Though large, the lightweight Geofoam blocks are easily maneuvered by two laborers and can even be customized to virtually any shape with a hand-held hot wire cutter.

“Though this building is both bold and dramatic, when it comes to material selection we are not looking to be risk takers,” finishes Harris. “Like the design for 150 North Riverside itself, Foam-Control Geofoam provided a confident approach to a unique engineering problem and contributed greatly to an overall wonderful building solution.”

About the Author
Sean O’Keefe is an architecture and construction writer who crafts stories and content 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.

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Explore the iconic, new US Olympic Museum through the lens of architecture and construction writer Sean O’Keefe

By Sean O’Keefe

construction writer
Construction Manager GE Johnson Construction pushes the envelope to deliver the iconic U.S. Olympic Museum in Colorado Springs

Leaving a legacy often requires a lifelong fortitude of purpose and character that only the best among us can realize regardless of pursuit. In athletics, the pinnacle of success is that of an Olympic gold medalist, a champion among all of mankind. In construction and design, legacies may not be as easily quantified but once the truly spectacular is achieved it’s hard to overlook. When the new United States Olympic Museum in Colorado Springs, Colorado opens to the public, it will unmistakably add to the legacies of design architects Diller Scofidio + Renfro (DS+R) and General Contractor/Construction Manager GE Johnson Construction Company.

“The incredible architecture we are delivering is challenging all of us to think beyond boundaries,” says GE Johnson Superintendent, Tim Redfern, an industry veteran of more than 25 years. Redfern and GE Johnson Construction’s team are tasked with assembling a structure unlike any other ever built.

DS+R’s design for the US Olympic Museum takes its athletes as inspiration; the design idealizes athletic motion by organizing its programs – galleries, auditorium, and administrative spaces – twisting and stretching centrifugally around an atrium space. Arriving at ground level, visitors are whisked to the top of the building via elevator where they are greeted by a grand view of snow-capped Pikes Peak, an ode to Olympus with its own majestic presence. Circulation unfurls organically, gradually spiraling down through the museum’s series of loft galleries at a pace propelled only by the individual’s own inquisitive nature and gravity. The folded planes of the building’s superstructure create helical volumes of space circling the introspective atrium. Dissected by the structure and connected by a continual downward ramp, perched floor plains filled with interactive galleries will memorialize the accomplishments of U.S. Olympians past, present, and future.

architectural writer

“The dynamic building form defies typical construction. Thinking outside of the box is not an adequate description of what we’re doing to make this happen,” shares Redfern. The design’s diverse elevations  called for fifteen independent concrete slab-on-metal deck elevations, scaling just four stories of construction with no two planes running parallel for long. Structural tolerances are ultra-tight, becoming even less forgiving as the structure goes up – the opposite of most builds. The exterior frame tolerance is two inches, while interior frame tolerances are only a quarter of an inch, with just an eighth of an inch of deflection. Controlling precise placement of every piece of an exceptionally intricate puzzle like the United States Olympic Museum is a process that can only be accomplished through what GE Johnson thinks of as a spirit of continuous improvement.

“Normally, once you have things figured out, construction becomes routine,” says Project Manager, John McCorkle. “I don’t see that happening here. We’re continually questioning how we do things. The ingenuity of this structure demands constant collaboration with designers, builders, fabricators, and installers. Everyone will be learning all the way until the end.”

GE Johnson is pre-thinking and rethinking every move by incorporating a 3D point cloud that provides an accurate digital record of physically intangible space. All subcontractors are required to use the point cloud to develop approvable shop drawings. The point cloud is integrated with the BIM model, which draws from several computer-aided design, graphics, engineering, and manufacturing programs, along with the discipline-specific platforms of a variety of different subcontractors. Integrated work plans developed with subcontractors define every aspect of each construction activity including who, what, when, and where. Most importantly, plans will detail how each piece is assembled, verified, and validated for accuracy against the overall model as tasks complete. Looking beyond typical clash detection, GE Johnson’s fully detailed steel fabrication model allows the clearances of each structural framing member to be independently checked to make sure the design’s distinctive shell of diverging planes and scaled metal skin reads as intended.

“There will be a high-level of scrutiny on a building like this because of the iconic architecture,” says McCorkle of the pressure on GE Johnson to deliver the signature design.

US Olympic Museum Panel Detail

The museum’s unique exterior skin aptly illustrates the intricate precision of purpose and combination of expertise required to succeed at the Olympic level. The facade will be covered in more than 9,000 individual diamond-shaped anodized aluminum petals that interlock to form a single, beveled surface with integrated drainage channels. In total, an estimated 27,000 anchor points will attach the exterior wall sections to the structural frame. The specific details of every panel from backing materials, sheathing, and waterproofing will all be independently analyzed within the model because seemingly every petal is either uniquely shaped, placed, or attached.  GE Johnson brought highly specialized subcontractors who had previous experience with similar configurations onto the team to achieve the use of these unusual building materials and intricate assembly processes.

US Olympic Museum Exterior Mock-up

“Premium-quality construction is always a collaboration,” says McCorkle. “Delivering this design uncompromised means getting out of the comfort zone and seeking capabilities beyond our own.” Early in the problem-solving process GE Johnson worked with design architect DS+R, architect of record Anderson Mason Dale, and structural engineer KL&A on refining the micro-framing system that attaches exterior wall sections to the structure.  To address the complex sub-framing of the skin, through a design-assist collaboration, GE Johnson and the team decided to work with Radius Track, renowned for developing curved, cold-formed steel framing, to develop a buildable system. Through continual collaboration, the team was able to optimize wind-girt supports, which increased certainty and repeatability in installation while also decreasing costs overall.

Even as the structure reaches its highest elevation, preconstruction activities continue. For the specialized subcontractors developing a sequence of efficiently attaching the exterior skin to the structure, nothing is more valuable than the full-scale exterior wall section being erected on-site. McCorkle and Redfern estimate that the 20’ x 20’ mock-up wall section will require more than 1,000 labor hours to assemble and will likely cost in excess of $150,000 to build. Eight different subcontractors must delicately interlace their work through a maze of structural framing, light-gauge framing, waterproofing, drainage, glazing, and aluminum panels. Identifying components within wall sections that can be prefabricated off-site, like the micro-framing system and laser cutting framing plates, increases quality control and supports repeatable processes during construction. Each component is individually numbered indicating where, how, and to what it attaches like a giant model and each placement can be checked against the point cloud to verify accurate alignment.

Thinking outside of the box hasn’t been limited to solving challenges on the outside of the building. Placing the museum’s extremely large, yet whisper quiet, air handling unit has presented a series of sequencing challenges with a ripple effect that will likely continue to reverberate.

“It’s low-speed, high-volume and is by far the largest air handler I’ve ever put in,” says Redfern enthusiastically. “The size dictates a basement placement, which meant installing it before we put in the structural steel for level one.” Once installed, this unorthodox situation left the massive (and expensive) unit unprotected from the weather until the floor above it could be dried in. Complicating matters, structural engineering indicated that the concrete floor slabs across the building’s many elevations should be poured from the top down to deflect loading. Waiting until the museum’s 15 elevations were poured and cured would greatly extend the exposure period for the mechanical system, presenting significant risk, and an extremely difficult situation to rework if the unit was damaged. ‘’We encouraged the owner and design team to install terrazzo on the first level floors in lieu of stained concrete so that floor placement could be moved up in the schedule, increasing protection of the AHU and equipment below.”

Placing the air handling unit first also required fireproofing the basement before setting structural steel, one of several conditions, which make multiple mobilizations of key trades likely throughout construction.

“We have been empowered to use ingenuity to solve complex challenges at every turn on a very, very cool building,” finishes Redfern. “GE Johnson is using anything and everything we can to build this right. Pushing boundaries, gaining outside expertise, and asking more of oneself than others will is the Olympic spirit this museum is being built to honor.” 

About the Author:
Sean O’Keefe is an architecture and construction writer who crafts stories and content based on 20 years of experience and a keen interest in the people who make projects happen.

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More Than A Garden

architecture writer
The Freyer-Newman Center for Science, Art, and Education at the corner of 11th and York will showcase the full depth and breadth of the Gardens’ collections, capacities, and outward ambition of changing the world.

Originally Published in Colorado Construction & Design
Fall 2018
By Sean O’Keefe

The vibrant spirit of Denver is in full bloom at Denver Botanic Gardens, a place where a palatable sense of rejuvenation is evident around every corner. From the Mordecai Children’s Garden climbing the hill to the York Street parking structure, through the Bonfils-Stanton Visitor Center and Gift Shop to Hive Bistro and the Science Pyramid’s scale-like skin, seemingly every angle of the property has been reinvigorated over the last decade. As members and regular garden visitors will attest, despite a steady drumbeat of change and near-constant construction since 2009, the process, though systematic, has felt organic and largely unobtrusive.

“Denver Botanic Gardens has thoughtfully invested $113 million on about 60 different projects in the last decade,” says Brian Vogt, CEO. As measured by visitation, the investment is paying off. Today the Gardens welcomes 1.3 million people a year, making it a close second to Longwood Gardens outside of Philadelphia for the most visited Garden in America.

Denver Botanic Gardens’ history, which Vogt shares succinctly, stretches back to 1940 and includes a stop in City Park before settling on what was then Denver’s oldest cemetery along the eastern edge of Cheeseman Park in 1959. Since then a campus of exceptional architecture has emerged. Based largely on mid-century modernist principles, the designs integrate built and natural spaces and promote open-span spatial proportions through post and beam structures.

Having previously served as president of the South Metro Chamber of Commerce for 14 years, Vogt was a key figure in the founding of the city of Centennial in 2000 and understands the importance of big-picture thinking. When he took the reins of Denver Botanic Gardens as CEO in 2006 he immediately set about applying his experience corralling people and resources to achieve a grand vision through common objectives.

“We undertook a strategic master plan; launched a massive capital campaign; added several new pieces of architecture; and revitalized the existing buildings in this amazing collection,” continues Vogt. Ranging from minor to major, visible to unseen, the improvements made on Vogt’s watch have all been folded into the Gardens experience with as little disruption to visitors or services as possible. “The Freyer-Newman Center for Science, Art, and Education will be the grand finale of a tremendous community commitment to the Gardens’ sustainability for the next 50 to 100 years.”

Anticipated as a public-facing gem enticing passersby from the corner of 11th and York, the new 50,000 square-foot building will be the only space in the Gardens’ portfolio that doesn’t require a ticket to enter. The two-story, prairie style influenced design posits the building as the backdrop for the Gardens landscape, giving the natural order the reverence it deserves. Stout tulip-tree structural columns straddle the entrance behind the landscaped entry plaza, which will greet visitors with a handsome handshake and calm confidence.

The building seems to defy a simple programmatic descriptor, its contents a collection of functions. It will house a combination of research, laboratory, office, educational, gallery, exhibit, and public gathering spaces all connected by a common core. It is designed to showcase the many varied activities of the science of botany and horticulture. Due to the sensitivity of laboratory and research components of the herbarium where plant samples are tested, studied, dried, and stored, ironically, it’s the only building on the campus that won’t have any living plants in it.

architecture writer
Davis Partnership’s design draws upon the abundant inspiration found in the Gardens’ mid-century modern architectural assets. The structural columns designed for the project reference the tulip-tree lights along the Conservatory’s promenade.  

“Programmatically, this project was like putting together a puzzle with all of the pieces upside down,” says Patrick Lee, the design team’s project manager and an associate with Davis Partnership Architects. Lee, who has been a Denver Botanic Garden member for more than 15 years, shares that he really didn’t understand all of the things the campus had to offer before starting the project because so much of it was hidden away. From the Gardens’ rare book library, classrooms, conference rooms, botanic illustration instruction and collections, galleries, and a 270-seat auditorium, the Davis team was tasked with packaging a multi-dimensional building program within a framework of intuitive navigation and high, public visibility.

“The circulation and adjacencies are organized around the large, central atrium, a day-lit space dappled in shadow created by wooden slats latticing the skylight overhead,” continues Lee. “The user experience and sequencing are bound together through transparency and biophilia.”

Like those outside, the tulip-tree structural columns within the atrium mimic the Gardens’ original tulip tree lights and, along with the 50’ x 90’ skylight, respond to the innate human tendency to seek connections with nature and other forms of life. In imparting this sense of spatial accessibility and the power of biodiversity, Davis was able to draw on abundant inspiration from the Gardens’ varied tapestry of landscapes, the Boettcher Memorial Tropical Conservatory, and many other campus assets.

The connections within the design extend beyond the building, figuratively and literally, with the new facility establishing an axial relationship through the Boettcher building and south on a direct line to the Waring House at 9th and York. The second floor incorporates a pedestrian walkway passage from the Boettcher building, which concludes with the ellipse gallery. The oval viewing room will pantomime the ellipse found in the Waring House courtyard at the southern terminus, which prominently displays a prized sculpture by world-renowned artist Dale Chihuly.

“The building is stitched into the site, integrated yet distinctly independent in public accessibility,” says Daniel. “We are continuing the Gardens’ legacy of referencing the campus’ wonderful preceding architectural accomplishments.”

Delivering the established design intent on the ultra-high-profile project within budget and on schedule is a task that fell with honor to GH Phipps Construction in a Construction Manager/ General Contractor role. GH Phipps delivered the original Boettcher Memorial Tropical Conservatory in 1966 and has been a mainstay in the Gardens’ construction over a long, sustained relationship.

“GH Phipps is extremely proud of our 50+ year history with Denver Botanic Gardens,” shared project manager, Adam Tormohlen. “I started my first project here in 2008 and have been engaged in one project after another ever since. I live in the neighborhood and walk here with my children. The opportunity to intertwine all of Gardens’ programmatic and architectural diversity into a single facility is incredible.”

architecture writer
The grand atrium gallery at the level one entrance offers more than a glimpse into the many facets of the Gardens’ programs, professionals, and the scientific pursuit of connecting people with plants.

Tormohlen and GH Phipps teamed closely with Denver Botanic Gardens and Davis Partnership through 18 months of preconstruction services. The team invested in three rounds of constructability and value-engineering reviews to give the owner what they wanted without sacrificing design intent. A key change occurred in the size of the skylight, which was originally designed to be approximately 30 feet longer. The reduced volume was strategically subsumed without diminishing the volume of light reaching the ground level from above by reducing coverage over second-floor overhangs.

As construction begins to go vertical, Tormohlen and the GH Phipps team are looking forward to many more exciting months of building. Exacting detail in site logistics and subcontractor sequencing are essential with limited laydown room and a steady stream of concerts, events, deliveries, and public passage taking place just steps from the site. Construction must also, of course, account for to sustained protection of every single tree on the site, each a cherished asset in the museum’s living collection.

“Denver Botanic Gardens is working in every county in the state of Colorado, and globally, connecting people with plants, especially those native to the Rocky Mountain region for the delight of all,” says Vogt with well-earned enthusiasm. “There are important messages about the natural order and the world that we need to convey to as many people as possible. This building will be the centerpiece of our core function of changing the world.”

About the Author:
Sean O’Keefe writes architecture and construction stories and content 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    303.668.0717

 

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