The project is the expansion of an existing building—123 Sangamon—onto an adjacent parcel. The new addition adds 104 apartments in studio, one-, two-, and three bedroom floor plans to the building’s 45 loft apartments.
Residents have access to 7,000 square feet of amenity spaces including a Business Center, Theater Room, Lounge, Breakfast Café, and fitness room on the ground floor. On the fourth floor, another amenity suite includes a kitchenette leading out to the building’s outdoor pool, lounge, and grill areas. Atop the building’s 10th floor, accessible from the penthouse level, another landscaped patio allows visitors to take in panoramic views of the city. The building’s base will include parking for 130 vehicles as well as office spaces for building management functions.
The building’s Girder-Slab structural system–the first time used in Chicago–was chosen for its value, speed of erection, and low floor-to-floor heights. Girder-Slab is a prefabricated system of modified steel girders that allow precast concrete slabs to sit within the channel between beams–rather than on top of those beams–so floor-to-floor heights are greatly reduced. As a result, the building includes an additional floor in the same overall building height when compared to traditional steel structure design.
Critically, the girders, the precast slabs, and the building’s exterior concrete panels were able to be fabricated off-site and trucked in. This reduced labor cost and allowed construction to continue throughout the winter, saving an estimated eight weeks of construction time compared to weather-sensitive building systems.