Chicago Expands ADU Program to Boost Affordable Housing

Chicago has taken a major step toward addressing its housing shortage as Mayor Brandon Johnson and Alderman Bennett Lawson secured passage of Ordinance SO2024-0008918, which legalizes the construction of Additional Dwelling Units (ADUs) across the entire city. The measure aims to expand affordable housing options, promote multigenerational living, and encourage gentle increases in neighborhood density without disrupting community character.

“Today we take a critical step forward in our mission to ensure every Chicagoan has access to a decent, affordable home,” said Mayor Brandon Johnson. “By expanding ADUs to communities across the City, we are increasing housing availability and driving sustainable neighborhood investment. While this is a moment to celebrate, our work continues. We will continue to push for the needed reforms and community investments, which will make ‘housing as a human right’ a reality for every Chicagoan. I want to thank Alderman Lawson for his unwavering leadership and commitment to this measure.”

The new ordinance builds upon previous pilot programs by allowing both internal conversions—such as basement and attic apartments—and detached coach houses in most zoning districts. It also removes restrictive spacing and permitting requirements that had slowed earlier ADU construction. Alderman Lawson, who championed the measure from his first day in office, emphasized its significance for both residents and local workers. “On my first day as Alderman, I introduced an ordinance to authorize ADUs citywide because I believe Chicago needs bold, creative solutions to meet our housing crisis head-on,” he said. “With today’s passage of this historic policy—and with input from residents, developers, and our labor partners—we are taking real steps towards addressing our city’s housing shortage while creating good-paying jobs right here in our communities. This is a testament to our ability as members of City Council to get big things done through listening and collaboration.”

The reform legalizes ADUs “by right” in all non-single-family residential, business, and commercial zoning districts. For single-family areas, participation will depend on neighborhood opt-ins, though regions included in the earlier pilot are automatically covered. City officials estimate the change will more than double the number of eligible parcels—from roughly 116,000 to 245,000—greatly expanding the potential for new affordable housing across Chicago.

The ordinance is the result of close collaboration between city agencies, labor groups, and community advocates who drew on insights from the pilot program to strike a balance between affordability, neighborhood preservation, and workforce growth. To ensure affordability, every second ADU built on a property must be rented at an affordable rate. The Department of Housing (DOH) will also create grant programs to assist low- and moderate-income residents or property owners who dedicate ADUs to affordable tenants.

“In the midst of a national housing supply crisis, cities like Chicago must lead with smart, scalable solutions. Additional Dwelling Units are flexible and community-centered housing options that meet families where they are,” said Housing Commissioner Lissette Castañeda. “ADUs help us create more homes without displacing residents or reshaping neighborhoods, and they give homeowners the tools to build stability, support loved ones, and invest in their communities. This is how we grow housing supply with urgency and equity.”

Mayor Johnson has placed affordable housing at the center of his administration’s agenda, positioning ADU expansion as part of a broader push to make the city more accessible for working families. His “Cut the Tape” initiative will further streamline development and permitting processes, ensuring reforms translate quickly into real housing opportunities for residents across Chicago.