How to House Your Family—and Make it Affordable

Despite the potential to provide more affordable housing, accessory dwelling units (ADU) are currently illegal to build in much of St. Louis. A new city bill could change that.

Often referred to as granny flats or in-law suites, ADUs are built near or inside existing homes and provide a separate living space from the main house.

You might hear of the university student who rented out space above someone’s garage or in their basement to afford an education–that student is renting an ADU. And if you search Airbnb (with the filters “Entire Place” and “Guest House”), you can get an idea of what ADUs might look like.

Historically, ADUs have been used to house older family members or relatives—hence the names granny flat and in-law suite. This helps promote multigenerational living, making it easier to maintain relationships with close friends and family (which could help ease a recent increase in loneliness).

ADUs are not currently illegal by name in the City of St. Louis, but a convoluted set of regulations make it extremely difficult for many homeowners to build them; the city requires 4,000 square feet of land per dwelling unit, so residents need at least 8,000 square feet of land to build an ADU. Additionally, parking minimums and setback regulations make it very difficult to build ADUs in homes of certain sizes and shapes, even on larger lots.

ADUs can help lower-income residents afford mortgages and other living expenses while also providing an affordable living space for renters. They also have the potential to increase the value of homes for owners—the extra living space, as well as the potential to rent it out and earn passive income, can increase a home’s appeal.

Board Bill 43 will allow ADUs to be built and used in all residential zones of the city (this interactive map shows how the city is zoned if you’re interested).

Allowing people to use their properties as they see fit and strengthening the rights of homeowners will let the market work freely, increasing the amount of affordable housing in Missouri. This is a much better approach to affordable housing issues than misguided regulations and tax-credit programs.

The now awaits discussion in the Housing, Urban Development and Zoning Committee.