The Boston Planning & Development Agency is looking for a developer to build on a 261K SF parking lot site in Charlestown.

The agency released a request for proposals, with responses due by July 10, for the rights to develop the Austin Street parking lots via a 99-year ground lease.

The city held a pre-bid conference May 24, and public records show representatives from several major Boston developers were in attendance, including Pennrose, Related Beal, Samuels & Associates, The Davis Cos. and Rise.

The RFP says the development proposal that is picked will need to adhere to the PLAN: Charlestown goals, including housing creation for all income levels, a swath of public open space, and pedestrian and bicycle connections to Bunker Hill Community College, Banker & Tradesman first reported.

For projects the BPDA will consider, 60% of the residential units proposed must be restricted to households making up to 80% of the area median income for rentals and 100% AMI for homeownership units.

The Mayor's Office of Housing is also willing to take requests for funding for proposals looking to add deeper affordability options, especially for Section 8 voucher holders.

The BPDA added three scenario graphics of what the site could be developed into. These scenarios encourage a variety of building heights, with the larger buildings set in the back, closer to I-93.

Other considerations for the site include ground-floor retail options for each of the buildings and open space, including the creation of a sports practice field that the neighborhood has expressed interest in.

The BPDA opened the RFP process last month and will answer questions about it until June 15. Submissions for the RFP close on July 10, and the BPDA will hold a live proposal opening the same day.

The Charlestown site isn't the only parking lot property the city is considering for redevelopment.

The city has held meetings for the 4-acre Boston Water and Sewer Commission parking lots in Roxbury, hoping to spur development on the underutilized site. Another parking lot in Chinatown is going through a second round of proposals after initial plans fell through.