The Bronx’s Grand Concourse is no stranger to great architecture, though it has been nearly three-quarters of a century since the Champs-Élysée–inspired boulevard has seen the likes of Bronx Borough Hall, near Yankee Stadium, and the countless art deco and art moderne apartment buildings that make it one of New York’s most impressive thoroughfares.

With its centennial three years away, the Grand Concourse is undergoing a renaissance anchored by new developments targeted at revitalizing the South Bronx. One of the first and most notable additions is a $19 million expansion of the Bronx Museum of Art, designed by Bernardo Fort-Brescia and his firm Arquitectonica.

Rising three towering stories above the busy street, the northern wing of the museum is the first phase of a project that will literally unfold to the corner, eventually replacing the squat former-synagogue the museum has occupied since 1982. It adds 16,700 square feet to an existing 33,000.

The aluminum-clad façade resembles an abstract paper fan, comprising seven irregular masses that are broken vertically by columns of fritted glass that spill light into the galleries. The dynamism created by the folds is heightened by diagonal incisions into the aluminum. Fort-Brescia explained that the crinkled frontispiece admits the dominant western light indirectly so it will not damage the art.

The entrance of the Bronx Museum.

“Through the innovations of this pleated façade, it is our belief that it will not only serve to heighten the positive profile of the Bronx but also establish the county as a vibrant cultural destination,” Mayor Michael R. Bloomberg said during the ribbon cutting ceremony on October 3.

Perhaps the greatest service the glass provides is a “storefront” atmosphere. The two-floor lobby will house a public gallery, allowing pedestrians to steal a quick peak of art and maybe even be tempted inside.

“It’s folding, it’s gesturing, it’s three dimensional,” Fort-Brescia said. “We wanted people from the street to look in. Part of the point is to make the cultural building the center of the city.”

Behind the lobby is one of the new large gallery spaces; designed with four flat walls, it may be closed off for projections and other installations. Above this sits the main gallery, which stretches from the jagged but functional wall out to an enclosed rear terrace that seems to float above the ground.

At the very top is a new classroom and media lab. “We were in the basement before,” Education Department Director Lynn Pono said. “It’s such a contrast. The light is amazing.”