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Willis Tower Project Profile



Chicago, IL

Job Size:

87,391 sq. ft.


Gensler Architects


When you think of a big city, often what immediately jumps to mind are skyscrapers, traffic, and your favorite sports team. But many of these big cities are also known to produce a lot of emissions that spread into the atmosphere. One of the biggest culprits of this growing problem—Chicago.


Yes, the Windy City is responsible for 2.6% of the national carbon footprint. According to Merriam-Webster, a carbon footprint is the number of greenhouse gases and carbon dioxide emitted by something. One way to combat this carbon footprint is to install a green rooftop!


So when renovations were scheduled to expand the base of the Willis Tower in Chicago, the team at Gensler Architects made sure to incorporate a green space within their plans, which focused on creating a welcoming, true-to-the-city atmosphere.


“Gensler carefully studied how existing spaces in Willis Tower were being used in order to create a true Chicago-born environment that reinforces a highly active, neighborhood-scaled experience. Named “Catalog,” an homage to the building’s original tenant, the Sears Roebuck Company, the reimagined base of Willis Tower will connect Chicagoans and visitors with five levels of retail, dining, shopping, and immersive entertainment. The design extends the streetscape, creates community, and engages visitors in a one-of-kind, only-in-Chicago experience. From street to sky, the building will provide inviting hospitality on an unmatched scale, dissolve the borders between work and life, and foster a collaborative, warm atmosphere.” (via Gensler’s website


What has begun to emerge at the base of Willis Tower is an all-season urban destination known as “Catalog.” Named to pay homage to the building’s original tenant and namesake (Sears Roebuck), Catalog connects Chicago with five levels of dining, retail, and entertainment, as well as a transformed Skydeck experience. Designed to be warm and approachable, it extends the streetscape, creates community, and immerse visitors in true Chicago.

Set for a 2020 completion, one of the biggest challenges of this massive expansion is its vast vegetative rooftop.  When examining the requirements of this high-profile, three-year project, the building contractors turned to Barrett. Specifically, they decided to use the RamTough 250 with fabric reinforcement to help create an airtight waterproofing system that would ensure the success of this project.


RamTough 250 is a hot-applied rubberized asphalt membrane which forms a completely monolithic, waterproof system without seams or joints. RamTough 250 exhibits excellent adhesion to horizontal and vertical surfaces. RamTough 250 forms a robust monolithic waterproof system that does not allow water to migrate under the membrane.


For more information about our products, please visit our website at barrettroofs.com or call 440-605-1020.