St. Regis Chicago

The St. Regis Chicago, formerly Wanda Vista Tower, is a 101-story, 1,198 ft multi-use supertall skyscraper in Chicago, Illinois. Construction started in August 2016, and was completed in 2020. Upon completion it became the city's third-tallest building at 1,198 ft, behind the Willis Tower and Trump Hotel and Tower, and surpassing the Aon Center. It is the tallest structure in the world designed by a woman. It forms a part of the Lakeshore East development and overlooks the Chicago River near Lake Michigan.

Designed by architect Jeanne Gang and her architectural firm, Studio Gang Architects, the St. Regis complements the design of the nearby Aqua skyscraper, also designed by Gang, as the two tallest structures in the world designed by a woman. Initially a joint project between Magellan Development Group and Chinese based Wanda Group, the skyscraper cost nearly $1 billion to construct. Magellan bought the project entirely in 2020, and then partnered with St. Regis Hotels & Resorts, which opened the hotel portion on May 19, 2023.

The structure consists of three interconnected towers, called "stems" with differing heights in a step-like arrangement. The stems are formed from alternating truncated pyramidal shapes called "frustums", giving each tower an undulating appearance, further accentuated by differing shades of glass in alternating pattern. The composition has been likened to sculptor Constantin Brâncuși's Endless Column. According to Studio Gang Architects, the tower "presents itself as three interconnected volumes of differing heights, moving rhythmically in and out of plane" as a result of the curvilinear design. The tower topped out in April 2019.

Usage
The St. Regis Chicago is a mixed-use residential and hotel building consisting of the St. Regis Residences, 393 luxury condominium residences, and the St. Regis Hotel, with 191 hotel rooms, including 33 suites. The hotel occupies the first 10 floors of the structure with private residences on floors 11 through 97. Floor 47 is the dedicated private residential amenity floor with an outdoor pool, spa, Golf Lounge, and Fitness Center. In addition, residents have shared access to all of the St. Regis Hotel amenities, including the St. Regis Spa and in-room dining. The highest-priced sale at the St. Regis was a two-floor unit that sold for $20.56 million in 2022.

Design
The building's chief architect is Jeanne Gang, head of Studio Gang Architects. Chicago based bKL Architecture is the project's architect of record. The design has three interconnected volumes with differing heights. Totaling a height of 101 stories, the east, middle, and west towers are 47, 71, and 93 stories tall, respectively. Mechanical space occupies the remaining floors. Upon completion, Vista Tower designers are targeting a Silver Leadership in Energy and Environmental Design (LEED) certification.

The three towers feature a curvilinear design, and are made up of alternating frustums. The towers have 6 different shades of glass. The design was described as "stacks of tapering, truncated pyramids that alternate between right-side-up and upside-down" by the Chicago Tribune. The tower has a notably smaller footprint than other supertalls in Chicago with a building height-to-core aspect ratio of 40-to-1.

Condominium interiors were designed by hospitality design firm Hirsch Bedner Associates, while the hotel interior were designed by San Francisco firm Gensler. Philadelphia-based OLIN designed the project's green spaces, including the rooftop gardens. The structural engineering of the tower was managed by Magnusson Klemencic Associates.

Columns
Unlike most buildings, the building's perimeter columns step inward and outward instead of going directly upwards. Each column projects about 5 inches outward or inward from the one below it. This was chosen over using columns set on a diagonal, which would have sacrificed interior space.

Wind resistance
The tower uses coupled dual-core shear-wall assembly that connects the three buildings for wind resistance. The two outer cores are tied together via a 508-ft-tall reinforced concrete spine, from floors 15 to 51 above the upper street grade. For gravity loads, columns that continue to foundations support a 123-ft-long spine wall. This 2-ft-thick spine transfers wind loads from the middle tower to the cores of the 51-story tower to the east and the 101-story tower to the west.

The building contains uninhabited "blow-through floors" to reduce wind-induced sway. Six tanks, holding more than 400000 USgal of water, counteract the movement of the wind. A "spine wall" in the tower’s midsection links two outer cores, helping the two towers act as one unit. The wall is perforated so doors and hallways go through. A "buttressed core" in the two outer stalks are built out to the outer edge of the building. The outer walls are also perforated, leaving openings for windows. "St. Regis Chicago's design allows wind to blow directly through the building at Level 88. This double-height, blow-through floor confuses and reduces wind forces, resulting in a 20% reduction in overall building overturning forces."

Restaurants
The St. Regis Chicago has two independently owned restaurants. Miru, is located on the 11th floor of the middle-tower and is Japanese-inspired. In addition to its interior dining room, Miru has a large, north-facing outdoor terrace. In March 2024, Chef Evan Funk's Tuscan-inspired "Tre Dita" opened in the St. Regis Chicago. Both restaurants are owned and operated by Lettuce Entertain You Restaurants.

Reception
Edward Keegan of Crain's Chicago Business praised the design of the building, calling it "second only to Hancock in the gracefulness in its silhouette" and a "proud and soaring thing". However, he also criticized several engineering choices, notably the execution of the tower's blow-through floors.