CASE STUDIES

Photo courtesy of Bedrock

Figure 1. Hudson’s Detroit, aerial view at sunrise.

Photo courtesy of SHoP Architects

Figure 2. Hudson’s Detroit, skyline view.

Photo courtesy of Bedrock

Figure 3. Topping-out of Hudson’s Detroit tower, April 2024: aerial view showing steel facade support elements, plus Comerica Park (baseball) and Ford Field (US football) in the background.

HUDSON’S DETROIT

In downtown Detroit, on the site where J. L. Hudson’s flagship department store (Smith, Hinchman & Grylls, 1911) underwent controlled demolition in 1998, a new 1.5 million-square-foot mixed-use tower complex is rising to transform the skyline and contribute to the city’s revitalization. The new Hudson’s Detroit–the developer Bedrock is retaining a version of the historic name–will comprise two buildings, the 685-foot Hudson’s Tower with residences, an Ian Schrager/Marriott Edition boutique hotel, and exhibition space, and an accompanying 232-foot midrise with retail, office, and event space. Designed by New York’s SHoP Architects with Detroit firm Hamilton Anderson Associates, Hudson’s Detroit will add about 250 apartments totaling 441,500 gross square feet to the local housing stock. It will also attempt to heal the civic trauma of losing a much-lamented local landmark.

Buro Happold partner and New York co-office director Yasmin Rehmanjee points out that the project’s components called for multiple structural systems and materials. “The structural design for this project focused on efficiently addressing both the vision and programming needs of this iconic development. In high-rise construction, especially for mixed-use buildings, it is crucial to use the right materials in the right places. This principle applies equally to new construction and adaptive reuse.”

The office building has an all-steel structural system that allows “expansive, column-free office and event spaces,” Rehmanjee notes. “This was achieved using long-span beams and trusses at the offices as well as 90-foot-long trusses to create the versatile and open event spaces.” The lowest third of Hudson’s Tower uses structural steel, while its upper sections (including hotel and residential components) use concrete (shear walls, columns, and post-tensioned slabs) and steel facade support elements. “Given [that] steel columns take up far less space,” she says, “employing structural steel in the lower part of the buildings allowed for much significant space allocation for the spa, retail, and restaurant areas, providing great amenity spaces.”

The site holds not only memories for generations of Detroiters but the physical remnants of Hudson’s, once the world’s tallest retail building and a narrow second to Macy’s in square footage. “Many old substructure elements and foundation systems from the previous building remained underground,” Rehmanjee says. “We had to ensure that the new caissons avoided these old structures. Minimizing the size of the new foundation elements was beneficial and facilitated construction. Since structural steel buildings are generally lighter than concrete ones, using structural steel for as much of the project as possible reduced the building’s weight and, consequently, the size of the foundation elements.”

William Sharples, founding principal of SHoP, notes that Bedrock founder Dan Gilbert “envisioned this project from the beginning as a 24/7 hub for Detroit, which led to the dynamic range of uses in the civic building and directly impacted the design and engineering solutions. Structural steel was chosen to address the challenges posed by the need for large event spaces with multiple floors above, enabling 50-foot column-free spans that provide maximum flexibility. Another advantage of using steel, given the site conditions, is its application in the 400,000-square-foot office program at the top of the block. The long-span steel structure we used there allowed for column-free floors, providing greater flexibility and visual openness throughout the office levels while enhancing views into the atrium from every floor.”

Hudson’s Detroit scored a major win in April 2024, the same week as its topping-out, when General Motors announced it would move its world headquarters from Renaissance Center to the new complex as commercial anchor tenant. Residents of the tower, meanwhile, will enjoy hotel-grade amenities, 360-degree views of downtown and the Detroit River, proximity to Library Park and its surrounding cultural district, and a sense of becoming eyewitnesses to, perhaps participants in, their city’s long-awaited and repeatedly announced rebirth. Detroit’s troubles (poverty, population losses, 1960s riots, widespread streetlight outages, municipal and auto-sector bankruptcies) have received more national publicity than its victories (the restoration of Michigan Central Station, the removal or renovation of thousands of abandoned houses, the return of major employers, the unheralded vigor of its Black-owned businesses).

“Bedrock has committed to bringing additional residential units to Detroit, through both new construction and by restoring and maintaining the historic fabric of the city,” says James Witherspoon, Bedrock’s senior vice president of architecture and design. “About 50 percent of current residential units in downtown Detroit were added to the market in the last 10 years, and we continue to see a strong trend of new multifamily construction in the city” (Downtown Detroit Partnership). “We have developed an expertise in adaptive reuse and have converted a number of historic office buildings into residential, adding new units to the Detroit residential market, of which 30 percent is committed to being affordable housing. Where appropriate, structural steel provides the flexibility required to facilitate change of use in these historic buildings.” With Hudson’s again brightening its skyline, Detroit is gaining a prominent symbol of urban nimbleness and strength.

Photo courtesy of TenBerke Architects

Figure 4. Brook Street Residence Halls, Brown University (Chen, left; Danoff, right).

Photo courtesy of WSP

Figure 5. Chen Family Residence Hall, Brown University.

Photo courtesy of WSP

Figure 6. MassArt’s TreeHouse Residence Hall by Stantec’s ADD Architects, with structural engineering by WSP’s Odeh Engineers.

Photo courtesy ofWSP

Figure 7. Interior at the Brook Street Residence Halls, Brown University, with steel frame and CLT ceiling.

BROOK STREET RESIDENCE HALLS, PROVIDENCE, R.I.

The Chen Family and William and Amy Danoff Residence Halls at Brown University use a different form of hybrid structure to offer residents the aesthetics of exposed cross-laminated timber (CLT) while taking advantage of structural steel’s virtues: fast construction, long spans, thin members, compact columns, and strong environmental metrics. Designed by TenBerke Architects (formerly Deborah Berke Architects) with David Odeh’s WSP team as structural engineers, the paired five-story dormitories are similar in form and scale but not mirror-imaged. Angular rooflines and subtle irregularities in the fenestration pattern lend a contemporary touch to their contextual material palette of red, brown, and gray brick, the traditional materials of Providence’s urban fabric.

The intended occupants of the two five-story, all-renewably-powered halls are approximately 350 upperclass undergraduates, who often seek off-campus apartments in a city with a chronic housing shortage. Drawing these residents back to the College Hill campus relieves local housing-market pressure and contributes to Brown’s sense of coherence as an urban academic community. The project, like many academic residential buildings, offers a model of structural efficiency that can logically be scaled up beyond its own midrise level.

Odeh Engineers had already completed a similar steel/CLT building at Rhode Island School of Design, working with Nader Tehrani’s NADAAA Architects on the school’s North Hall (see Architectural Record, March 2, 2020); the firm’s academic residential experience also includes the widely heralded Tree House Residence Hall by Stantec’s ADD for Massachusetts College of Art and Design (MassArt), built of steel with slab on deck, using a braced-frame steel truss system using roof-level hat trusses to support its narrow 21-story volume dramatically cantilevered above a curved stone base. Though the Brook Street residences do not perform such structural acrobatics, their combination of CLT flooring and ceilings with an exposed steel frame reflects Odeh’s recurrent interest in arboreal architectural motifs and concepts.

“People like seeing timber,” he observes; “It’s a beautiful material. It’s called the biophilic effect. Using structural steel in combination with the timber allowed us to span longer distances with thinner members, and use very compact columns so that there are fewer vertical elements in the floor plan than a similar system using all timber, like wood columns with wood beams.” Steel’s light carbon footprint, along with renewable power from an off-campus solar facility, also helps Brown achieve its decarbonization aims: the university has pledged to cut campus-wide greenhouse gas emissions to net zero by 2040.

Copyright David Sundberg / Esto

Figure 8. 35XV, aerial view from west showing residential tower atop Xavier High School segment.

Photo courtesy of FXCollaborative

Figure 9. Diagram of 35XV in section, showing programs by floor.

Copyright David Sundberg /Esto

Figure 10. Transition point between residential and academic components of 35XV, with steel load-transfer structure.

35XV, NEW YORK CITY

FXCollaborative’s 347-foot mixed-use building at 35 West Fifteenth Street serves its community in two ways–a school component (Xavier High School’s Fernandez-Duminuco Hall) on the lowest six floors and 17 stories of residences above–and combines two structural systems accordingly. “The residential portion is built in concrete and the school portion at the base is built in steel,” notes architect Toby Snyder. The glazed residential volume is set back from the midblock streetscape with a separate entrance, cantilevered off a steel platform to hover 17 feet over the school and 36 feet over a rear yard, with a tapering form that preserves sunlight angles to the street, as New York setback buildings have done for over a century. The granite-clad school component includes classrooms, a laboratory, a commons, and a double-height space for Xavier’s music program. The seventh floor includes amenities for the residential component (gym, lounge, children’s playroom, wine cellar, and terrace). With separate vertical circulation for the two components, the residents and students need never mix.

At the building’s design stage, says Snyder, “That was a great moment to ask that question: Why not do the whole thing in steel? Or why not do the whole thing in concrete?’ And I think the reason really comes down to the program. What residential spaces need are rooms that are 10, 15 feet wide, fairly short-span spaces, and they don’t have a lot of need for complicated mechanical systems that go all the way out to the edge of the building envelope. A lot of the rooms that you have at the perimeter of a residential building are bedrooms and living rooms. They can get a lot of their mechanical service from further back in the building, where you can have lowered ceiling height.” Floor-to-floor heights in the school floors are much higher with wider spans, requiring the higher strength-to-weight proportions of structural steel.

Hybrid structures for mixed-use buildings have become something of a signature typology for FXC, Snyder says, calling for expertise beyond the individual components. “You have to understand all of these programs on their own,” he says; “you have to be able to do one on its own, and then you have to know them both truly on their own terms, and then you have to know how to put them together. So it’s like three kinds of knowledge.” In other mixed-use FXC projects involving school spaces, he says, “sometimes it’s a gymna-torium, or a cafe-torium, or a gymna-teria,” all of which require long-span structural members.

“We’ve done other hybrids where there’s some institutional component at the base and some sort of developer component at the top, whether office above school, office above church, residential above church, or residential above school,” Snyder recalls. “But we often make that structural change decision 80 feet up in the air. When it goes from one type of program to a different type, even if it’s concrete at the top part of the building, transferring that load often needs to be done in steel because you’re moving one location of column spans to a completely different one for what’s going on in the base. You can’t necessarily keep the same column grid throughout these different programs. They sometimes have independent cores, so the building can really have a big shift from the top to the bottom... and a lot of that load has to be transferred onto steel just to be able to do it in a shorter span.”

Mixed-use buildings like 35XV, Snyder adds, can be beneficial to “institutions that are potentially land-rich–they own a great asset–[but] cash-poor; they don’t have a great endowment. There’s a developer that wants to partner with them, builds them a brand new facility on their land that they own, and then on top of it, builds their profit-generating portion above it.” Such air-rights arrangements between not-for-profits and private developers call for expertise in the puzzling details of New York City zoning, he notes, as well as the details of matching structural materials to purposes. When the pieces of a hybrid project come together, “it makes business sense and programmatic sense, and for us, it makes architectural sense and urbanistic sense, because it creates a genuine mix of uses.”