CNA Center

The CNA Center is an International Style skyscraper designed by Graham, Anderson, Probst & White, and built between 1970 and 1972 in Chicago, IL.

CNA Center is not the only name you might know this building by though. It is common for companies to want to attach their names to iconic buildings when they move in, or for the general public to come up with nicknames, and this one is no exception. The building has changed names several times over the years, and is also known as:

• CNA Center until 2018.
• Continental Center III.
• 333 South Wabash.
• Big Red.

Its precise street address is 333 South Wabash, Chicago, IL. You can also find it on the map here.

The building underwent a major restoration in 2008.

Graham, Anderson, Probst & White was the architecture firm in charge of the architectural design.

That being said, architecture is a complex discipline involving many professionals from different fields, without whom this building would have not been possible. We will surely be leaving out a lot of names here, but at the very least we know that there was one other part involved, that was Environmental Systems Design, Inc. in charge of MEP Engineering.

The CNA Center can be categorized as an International Style building.

The CNA Center uses a frame structure made of steel columns and slabs.

A frame structure uses a combination of beams and columns to sustain the building's weight. The walls in this case are non-load bearing, which allows for more flexibility when distributing the interior spaces.

The facade uses a non-load bearing curtain wall system. This means the curtain wall modules are anchored to the building's structural frame, typically by being attached to the edge of the floor slabs. The curtain wall system connects to the slabs using brackets, anchors, and mullions, which transfer the loads imposed by wind and temperature changes, to the building's primary structural elements.

This setup allows the curtain wall to accommodate differential movement between the facade and the structural frame, such as thermal expansion, floor deflection, or sway from wind forces. This system's integration with the slab edges also allows for continuous insulation and weatherproofing layers.

From an aesthetic point of view, the facade features a continuous curtain wall that is its most characteristic feature since it was painted red. If the building was black it would not stand out from the collection of international-style skyscrapers in Chicago, such as the Equitable Building, the IBM Building or the skyscrapers on Michigan Plaza. But by painting it red the CNA Plaza has managed to stand out in the skyline of the windy city, becoming a recognizable landmark.