The New York City Council is expected on Wednesday to decide the fate of 5Pointz, the brick warehouses slathered in oversized graffiti that became a cultural institution in a once-working-class neighborhood of Queens.

The longtime owner of the warehouses, the Wolkoff family, is seeking to demolish the buildings to make way for two towers with a combined 1,000 apartments on a three-acre parcel near Citigroup Tower in Long Island City. Last week, the Wolkoffs agreed to set aside additional space for affordable housing and artists’ studios with the hope of winning approval for the $400 million project.

Those concessions came after negotiations with the local community board and Councilman Jimmy Van Bramer, a Democrat from Queens, over the proposed towers, which would be among the tallest in Queens. But many of the artists who spray-painted the walls with the multicolored art that attracted worldwide attention are unhappy that one of the few places dedicated to their aerosol craft would disappear.

“My father, Jerry, bought it over 40 years ago thinking he’d develop it 39 years ago,” said David Wolkoff, the principal of G&M Realty, a family-owned development company. “We’re now transforming it into other types of buildings.”