Basement apartments are a common sight in Chicago, though they haven't been considered legal residences since 1957. It was bad news for anyone back then who wanted to rent out a section of their property as an accessory dwelling unit. More than 60 years later, Chicago City Council voted to lift the ban and re-introduce ADUs. Is this good news? Don’t think so. Reversing the ban will do more harm than good

The law prohibiting coach houses or ADUs as primary residences came about as an attempt to prevent residents from circumventing the city’s zoning codes. By adapting their properties for multiple residences, owners could receive several rent payments with no increase in their property tax. This had the potential to drastically increase population density, which would disrupt the lives of residents. Chicago's zoning law passed in 1957 stipulated that owners would only be allowed to do this if they applied for expensive permits and zoning changes. 

More than 60 years later, the city council thinks that lifting the ban will help help reshape the city's economic growth and recovery from the effects of COVID lockdowns. The Urban Land Institute (ULI) called this “an innovative way for Chicago to address the growing housing challenge.” Perhaps that is true, but one thing is evident: re-introducing ADUs will cause a lot of unintended consequences.

While the city Mayor Lori Lightfoot and her administration might feel very positive about these coach houses and ADUs making their reappearance, it is unclear they are not concerned about the drawbacks. When people pass a law banning something, there is usually a good reason for it.

ADUs will cause more crowding issues and overpopulation. They will also bring in more noise, less parking space, and far less privacy. It stands to reason that ADUs will have a negative effect on the vicinity of accessory units to the neighboring structures on the expected use.

Of course, ADUs will also increase property value and bring extra income for homeowners. But what about their neighbors, whose property value will decrease because their home is suddenly located in a crowded neighborhood reduced privacy? 

Lifting the ban on coach houses and ADUs was a terribly bad idea, and Chicago will feel the negative consequences for decades.