President Barack Obama and First Lady Michelle Obama have selected a New York architecture firm, Tod Williams Billie Tsien Architects, to design the Barack Obama Presidential Center, the president’s planned library. The Obama Foundation announced the news on Thursday, ending months of speculation over which firms would grab the Obamas’ attention.

In winning the bid, Tod Williams Billie Tsien Architects, a firm captained by the eponymous married couple, edged out some of the top names in the design industry, including SHoP Architects (the firm that designed the Barclays Center), Diller Scofidio + Renfro (a High Line co-designer), and Snøhetta (the new San Francisco Museum of Modern Art addition). The Obamas passed on both European finalists: Renzo Piano (the new Whitney Museum of American Art) and David Adjaye (the Smithsonian’s National Museum of African-American History and Culture). John Ronan Architects, the only Chicago firm to make the finalist round, also lost out in the end.

In a short time, Williams and Tsien have made a name for themselves as sensitive project architects with a cool and casual style—not unlike, perhaps, the president who picked them. Their cultural spaces include the Logan Center for the Arts at the University of Chicago and the Lakeside Center in New York’s Prospect Park. TWBTA (as the firm is known in the industry) designed the former American Folk Art Museum, a tempered jewel-box of a building that was acquired and then demolished by the Museum of Modern Art to make way for that behemoth’s expansion. (Diller Scofidio + Renfro advised MoMA on the decision to tear down the beloved Folk Art building.)

The Barnes Foundation, designed by Tod Williams Billie Tsien Architects, pictured in 2015. (Matt Rourke/AP)

The firm’s best-known work is the Barnes Foundation in Philadelphia, a museum expansion, of a sort. Controversy swirled around this project after the board for the famously stoic, almost religiously staid modern art institution moved its $25 billion collection from its historic home in suburban Merion, Pennsylvania, to downtown Philly. Critics called it a hijacking. The nationwide debate over the museum’s move became the subject of a 2009 documentary, The Art of the Steal. That didn’t stop Williams and Tsien from wading into the controversy. Devotees of the original Barnes may never accept the new building, but in terms of design, Tod Williams Billie Tsien Architects made the best of a bad situation.

Once again the architects face a thorny situation in designing President Obama’s presidential library. Two sites in South-Side Chicago have been identified as potential homes for the library. Both sites carve out space from within existing historic parks, which means that the South Side gains a significant cultural space in the form of the presidential library but loses some part of either Washington Park or Jackson Park. (Both are the work of Frederick Law Olmsted and Calvert Vaux, the landscape architects who designed Central Park in New York.)

Proposed sites for the Barack Obama Presidential Center. (The University of Chicago)

If any architecture firm can navigate the cultural politics of the Obama Foundation seizing cultural park space to build President Obama’s library, it’s Tod Williams Billie Tsien Architects. According to the Chicago Tribune, Williams and Tsien will have some say in choosing the site. It’s almost as if the president has applied his overriding preference for calm and compromise—as he displayed recently with the nomination of the moderately conservative judge Garland Merrick to the U.S. Supreme Court—to the business of picking out architecture.

No doubt, Williams and Tsien will serve the Obamas well. The architects (and the Obamas) have an opportunity to serve Chicago’s South Side well, too, by preserving the neighborhood’s critical existing cultural assets while delivering them another important one.