727 West Madison | Chicago, Illinois | 2018

Architects: FitzGerald Associates Architects
Client: F&F Realty, Ltd.
General Contractor: Lendlease Corporation
Structural Engineers: WSP US
Photographers: Jess Smith / Sebastian Rut / FitzGerald 

The unmistakable feature of 727 West Madison is its sleek elliptical form.

The unusual floorplate creates memorable floor plans and stunning amenities, and a skin-to-floor area ratio makes for an exceptionally efficient design. The facade evokes movement with a ribbon pattern that spirals up the tower, accomplished with glass reflectivities so that the variation is imperceptible inside. The shape offers panoramic views from the 45-story tower's 492 apartments.

Special care was taken during construction to maintain the tight tolerances necessary for the window wall system. Matched with flush-mounted slab edge covers, it presents a luxurious curtain wall aesthetic at a developer-friendly price point. Outside, the tower stands as a beacon to the adjacent expressway, and a distinctive parking and retail structure sit along Halsted Street. The form was crafted to make the parking base feel like a separate structure while the elliptical shape of the tower is continuous to the ground plane.

727 West Madison's stunning elliptical footprint makes it an iconic addition to the Chicago skyline and helps to ensure this facade glimmers in the sunlight. However, the geometry of the slab created several unique challenges for the project team.

The facade, which is a window wall with a flush slab edge cover, required concrete tolerances to be strictly maintained. To ensure these tolerances were met, metal edge forms were used to provide a consistent shape and an award-winning concrete Tekla model was utilized for layout and tracking short-term movement. This allowed for a repeatable slab edge condition and provided the facade subcontractor with information that proved to be critical in establishing benchmarks for window wall layout.

Another unique design challenge was coordinating the post-tensioned cables with facade anchors. The structure design featured two sets of cables running the entire perimeter of the slab. The construction team worked with the design team to spread the sets of cables and establish a clear zone of roughly 2 1/2" for the window wall anchors. The post-tensioned cable placement was verified daily to make sure the cables did not shift prior to the concrete pours. No post-tensioned cables were hit by window wall anchors.