DUMBO’s industrial facades and celebrated view of the Manhattan Bridge will be preserved, as the city’s Landmarks Preservation Commission yesterday voted unanimously to designate the area New York’s 90th historic district. In recent years, the fast-growing Brooklyn neighborhood of DUMBO, which stands for Down Under the Manhattan Bridge Overpass, has transformed from a neglected industrial area into a trendy spot with luxury condo towers, art galleries, and restaurants — even a Starbucks.

The landmark designation would prevent developers from altering the facades of 19th- and 20th-century buildings located in a 20-block area. The brick facades, terra-cotta floors, and reinforced concrete structures of many of these buildings are unique architectural elements that have to be preserved, members of the Landmarks Preservation Commission said at yesterday’s hearing.

According to the commission, these buildings originally housed some of America’s most important manufacturing firms, including the coffee and sugar firm Arbuckle Bros., the paint firm W. Masury & Son, and the steel wool company Brillo.

While some critics consider the designation a hurdle to development, the chairman of the commission, Robert Tierney, said it was an opportunity to attract more interest in the area. “Preserving the neighborhood’s character will make people want to come here,” Mr. Tierney said.