a public lounge in the Willis Tower by Gensler
In a renovated public lounge, armchairs by Christophe Delcourt, Eileen Gray, and Pierre Jeanneret mingle with a Jaime Hayon side table and Mario Bellini coffee tables.

Gensler Enlivens the Street-Level of Chicago’s Willis Tower

At 1,451 feet, the Sears Tower was the tallest building in the world when it opened in Chicago in 1973. Designed by Skidmore, Owings & Merrill, it rises 110 stories over the Loop neighborhood and is a modernist icon, with a geometric structure and a facade of blackened aluminum and bronze-tinted glass. It’s also a landmark visible from across the city—so much so that locals still call it the Sears Tower, though it was renamed the Willis Tower in 2009. But it was always, as architecture critic Blair Kamin put it, “a dud at street level.” An austere plaza and a granite berm wrapping the base kept pedestrians at bay, and the public could only enter to visit Skydeck, the observation platform. In 2015, Blackstone bought the building and hired Gensler to rethink the site, which has resulted in a mixed-use attraction for office workers, tourists, and Chicagoans alike.

Todd Heiser, principal and managing director at Gensler’s Chicago studio, grew up in the city and found it surreal to take on the high-profile project. “It’s walking on hallowed ground,” he begins. “We approached it with humility, serving to amplify its positives and correct what was imperfect.” Willis Tower, he notes, was the product of an era of urban flight and single-use office buildings; it was designed to be impenetrable. But in the 21st century, aside from the early years of the COVID pandemic, cities have come roaring back to life and tenants seek dynamic, welcoming workplaces.

Designing an Amenities-Rich Hub in the Willis Tower

the exterior of the Willis Tower, refinished in black-anodized aluminum
Part of a 463,000-square-foot renovation project by Gensler, the main lobby of Chicago’s Willis Tower, formerly the Sears Tower, has been updated with steel columns and beams newly finished in black-anodized aluminum that matches the facade of the 110-story skyscraper.

Gensler brought the supertall up to date with a 463,000-square-foot makeover, including new entrances, lounges, and a transparent six-story podium with a food hall and a rooftop park—elements that prove why the firm not only ranks number one among the Interior Design Top 100 Giants but also third amid the Hospitality Giants (as well as 14th on the Healthcare list).

Heiser and Hansoo Kim, principal and design director at Gensler’s Washington office, started by researching how people used and moved through the building. They met with families visiting the Skydeck, who were often also looking for a place to have lunch, and office workers hoping to get to their desks quickly. “We had to support demographics of all ages,” Heiser says, and consider “the person who wanted to linger and the person who wanted a friction-free environment.” Kim adds that to create a vibrant multipurpose destination, they had to connect different types of programming, like coworking and retail, and “blur the boundaries between work, life, and play,” he notes.

Gensler Creates an Expansive Communal Space for All Ages

a public lounge in the Willis Tower by Gensler
In a renovated public lounge, armchairs by Christophe Delcourt, Eileen Gray, and Pierre Jeanneret mingle with a Jaime Hayon side table and Mario Bellini coffee tables.

The block-long building has entrances on three different streets (Wacker, Jackson, and Franklin). Originally, there were two for tenants and one for Skydeck visitors. Gensler opened them all to the public. “The entire base of the tower is now porous,” Heiser continues. Like a transportation hub or civic plaza, it hosts everyone from United Airlines employees who work in the building to toddlers and Midwestern retirees; the Skydeck alone draws 1.7 million visitors a year. Security is discreet. There are guards and cameras, but nothing like the airport-style measures we’ve come to expect in skyscrapers since 9/11. Touchless turnstiles use fingerprint scanners to admit employees into the tenant elevator bank at the building core.

Gensler, which partnered with SkB Architects on the facade, also reimagined the design of the entrances. At the Wacker Drive entry, earlier renovations had added a barrel-vaulted glass lobby and stainless-steel cladding on columns. The teams demolished the former and installed a portal of white-glazed terra-cotta, a common material in Loop architecture, and replaced the incongruous cladding with black-anodized aluminum that complements the original facade. (Gensler, which also tops our Sustainability Giants list, recycled more than 24,000 tons of demolition material.)

The existing entry sequence had its own issues: Visitors went downstairs to get to reception. “It was like walking into a bowl,” Heiser recalls. “You should be able to walk in and go up, because that’s logical.” A backlit staircase now leads to the main level, on the second floor. Here, Gensler leaned into the ’70’s glamour of the building’s heyday. An existing travertine wall was polished and unobstructed for the first time, and a lounge has been furnished with such late mid–century signatures as Cini Boeri’s furry Botolo chairs and chain-mesh drapery.

At the top of the stairs hangs a site-specific artwork: Jacob Hashimoto’s cloud of paper-and-resin discs. Its location in the Wacker lobby implicitly connects it to an Alexander Calder sculp­ture that originally hung there. “The client sought an installation as impactful as the Calder,” Heiser says. Gensler also commissioned an outdoor sculpture from Olafur Eliasson to mark the entrance to the new retail podium on Jackson Boulevard.

a ceiling installation of paper and resin discs in the main lobby of the Willis Tower
Composed of 7,000 paper-and-resin discs, Jacob Hashimoto’s site-specific In the Heart of this Infinite Particle of Galactic Dust fills the main lobby.

Gensler built the glass-walled podium on what had been an unwelcoming granite plaza, extending the base of the building to the sidewalk. The centerpiece of the addition is a soaring atrium and food hall called Catalog, a nod to the Sears mail-order business, that brings together local eateries beneath an enormous skylight. Diners can slide onto oak benches under bistro-style lights and look up at the tower. “Our goal was to create a Chicago streetscape inside the atrium, so you feel like you’re outside,” Kim explains. Above Catalog, a public roof garden with winding paths and native prairie grasses faces a neighboring park. Like the rest of the podium, it connects the building to the street and draws pedestrians into the once-forbidding landmark.

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Inside the Spacious Street-Level of the Willis Tower

inside the entrance to the Willis Tower
Treads of honed Kirkby stone and illuminated glass risers form the stairs to the main lobby.
one of the entrances to Willis Tower, clad in white-glazed terracotta tiles
White-glazed terra-cotta clads the new entry portal on Wacker Drive, one of three building entries, codesigned with SkB Architects; photography: Tom Harris.
a ceiling installation hanging over the lobby of the Willis Tower, formerly the Sears Tower
Marble flooring meets an existing but newly refurbished and revealed travertine wall dating to 1973, when the Sears Tower first opened.
Olafur Eliasson’s 30-by-60-foot Atmospheric wave wall
Olafur Eliasson’s 30-by-60-foot Atmospheric wave wall, made of 1,963 motion-activated, powder-coated steel tiles, appoints an elevation of the site’s new six-story podium, which features a public food hall and a rooftop park, on Jackson Boulevard; photography: Tom Harris.
inside the Catalog food hall in the Willis Tower
Inside the podium structure, a vaulted steel-framed skylight measuring 75 by 85 feet crowns the Catalog food hall, where LED pendant globes hang from a catenary system.
oak booths provide seating in the lounge
Back in the lounge, ’70’s-esque chain-mesh drapery counterpoints custom oak booths.
an atrium inside the Wills Tower
Third-floor office-tenant spaces overlook Catalog’s 70-foot-high atrium.
a rooftop park on the podium structure of the Willis Tower
Concrete-paver paths wind through native prairie grasses along the podium structure’s 30,000-square-foot rooftop park; photography: Tom Harris.
an eating area inside the Willis Tower
Heidi stools by Sebastian Wrong stand under Hoist pendant fixtures by Rich Brilliant Willing.
a small lounge in the Willis Tower seen from the building's exterior
Gianfranco Frattini’s Sesann sofa and Estudio Persona’s Nido chairs cluster around a Stahl + Band L Series table in a small lounge.
Gensler: grant uhlir; benjy ward; michael townsend; neale scotty; scott marker; stephen katz; hua-jun cao; kelly bogenschutz; marissa luehring; shawn fawell; todd desmarais; jeffrey peck; kim lindstrom; kate pedriani
skb architects: facade architect
olin: landscape architect
thornton tomasetti: structural engineer
esd: mep
v3 companies: civil engineer
burlington stone; campolonghi: stonework
parenti & raffaelli: millwork
clayco corp.; turner construction co.: general contractors
cascade coil drapery: chain drapery (lounge)
bloomsburg carpet: rug
pk-30 system: backlit wall
B&B Italia: sofa
cassina: black, white coffee tables
phantom hands: green chairs
novum structures: skylight (food hall)
tegan lighting: catenary system
concrete collaborative: flooring
newmat: stretched ceiling (lounge)
Avenue Road: green barrel chairs
hanover archi­tectural products: pavers (roof)
rich brilliant willing: pendant fixtures (food hall)
arflex: teal chairs
established & sons: stools
tacchini: sofa (small lounge)
estudio persona: chairs
stahl + band: coffee table
Pulpo: side table
linetec: custom aluminum cladding
boston valley terra cotta: terra-cotta paneling

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