The city is seeking design ideas for a redevelopment project over a former rail yard in Long Island City.

The applicants must provide details on how they will transform 11-24 Jackson Ave. into a 58,000 square foot space that includes “a mixed-use, mixed-income housing” building with a community facility and a public open space. The site’s underground area has been used by the LIRR to store cars.

The Request for Proposals is available online and submissions are due by April 21.