Offering one of the best office building locations in Chicago in terms of accessibility and visibility, this site would have been developed many years ago if not for its trapezoidal shape. Given that the east and west property lines are not parallel, fitting a typical Class A office floor plate, including the center core and desired lease spans, is a challenge. In addition, for any site along the river, the city requires a 30-foot-wide publicly accessible riverwalk, further complicating the site.
The design addresses the challenges with an unusual stepped center core, which allows for a 45-foot lease span on each side. To avoid an angled perimeter, the west wall has a series of 30-foot-wide, five-foot setbacks, accommodating an orthogonal, five-foot planning module throughout the building.
The state-of-the-art Class A office tower totals 56 stories and 1,770,000 square feet. Interior space planning is enhanced by the five-foot setbacks along the river, providing the equivalent of 14 corner offices. The setbacks create a distinctive form that accentuates the building’s verticality and avoids the pure box-like appearance of typical office towers. Lateral wind resistance is achieved through an optimized system of two-story outriggers and edge trusses at the mid-span of the building.
To satisfy the city’s requirements, the design provides a 45-foot-wide riverwalk that is covered, but effectively open to the sky, 55 feet above. Three large, tree-like structural elements spaced 90 feet apart transfer out the tower columns along the river and further open the site. These 83-foot tall, pronged columns consolidate the load to minimize the obstructions along the riverwalk and further open the site. The result is a landscaped, covered walkway that connects two very important pedestrian paths and maintains an effectively unobstructed river view. In combination with other space, the site is 50% open and publicly accessible at grade.
The riverfront promenade connects two important downtown pedestrian paths and a pocket park at the north. With the building hovering overhead, supported by nine tapered columns that meet in three structural nodes, the walkway features an unobstructed river view, offering roughly 22,000 square feet of welcoming outdoor space for the community to enjoy the natural asset of the river.
The structure is pre-certified LEED Gold and one of only two Class A offices in Chicago designed for WiredScore Platinum Certification. On the Wacker Drive side, a 45-foot-high lobby is enclosed by a cable-supported glass wall, and sculpted, folded-limestone cladding covers the elevator cores. The transparency of the low-iron glass wall virtually eliminates the distinction between interior and exterior space, with the lobby and streetscape becoming one. The advanced façade system offers significantly greater thermal performance for best-in-class energy efficiency.
The new building features extensive high-technology infrastructure designed to maximize overall health and wellness throughout. This includes the most advanced destination dispatch elevators in Chicago; and a multi-faceted, custom building app that provides touchless building access. The structure’s high efficiency best-in-class mechanical systems contribute to lower operating costs and enhanced air quality.
Goettsch Partners (GP) is an architecture firm with a global perspective. Based in Chicago, with additional offices in Shanghai and Abu Dhabi, the firm brings a singular approach to design that combines seasoned experience with a passion for exploration and innovation. Completed projects span five continents and represent a diverse range of types and sizes. Every project design begins with multiple concepts that are evaluated for intrinsic value, constructability and environmental impact. GP projects share a consistent visual language of bold clarity that celebrates highly crafted technical solutions delivering optimal performance. Visit www.gpchicago.com for more information.