Ald. Mike Verveer, District 4, said he has spoken with several local developers who are interested in partnering with the city.

"The downtown has seen relatively few affordable housing projects," Verveer said. "The possibility that many of these units could be designated as affordable workforce housing, to me, is a very laudatory goal and one that the mayor and I have agreed that we want to see happen."

According to the requirements, the proposals must also be compatible with surrounding buildings, including the historic Municipal Building. The city will also give high priority to projects that maximize the tax base and can be built in a timely manner.

To that end, a developer could proceed with the apartment project using a plan that has already received zoning approval from the city. This would speed up the process, because separate zoning approvals would not need to be granted.

Verveer said residential developments tend to be more straightforward and completed more quickly. Working with third-party commercial tenants has proved complicated in the past. The city worked with Exact Sciences in a previous iteration of the project before the company unexpectedly dropped out.