Looking for Chicago code defining a basement unit

[Alex F.]

Hi, I'm looking for someone who could point to Chicago code defining a basement unit, or someone who may have experience or knowledge regarding this type of situation.

When I purchased my multiunit house, the seller provided a a Zoning Certificate indicating 3 dwelling units. This was the expected number of units. However, at the time, I had not noticed that the certificate specifies that the dwelling units are on the first, second, and third floor. In reality, they are at the garden level and the two floors above.

The garden unit is only about 2 feet below grade and is otherwise a regular unit... full size windows in every room, high ceiling, front and back door, separate utilities and ventilation. I am wondering if this can actually be classified as the first floor unit. 

Does anyone know what specific criteria classify a unit as a "basement" vs a "first floor" unit? Is there something that says that a first floor must be 100% above grade?

Thanks for your help.

[Prashanth Mahakali]

@Mark Ainley thank you!!

@Alex F. Garden units are interesting and pose somewhat of a unique challenge. You have to look at them from a zoning code and building code definition. Per zoning code, the ceiling height will determine if it’s a livable space. Next the distance from grade to ceiling of that level would determine if it is a first floor or basement. If the height from grade to basement floor is more than the height from grade to ceiling of that level, it’s typically a basement. In “garden” units, this is not the case and hence may be classified as a first floor. Zoning code trumps building code in the preliminary definition of the unit.

Once you establish of it’s a basement or first floor units, you could have a “three story” building instead of a two story building.

When it comes to a zoning certificate it’s mostly useless in context of a building permit process to establish legal number of units. As an Architect, I have rarely submitted a zoning certificate to prove legal number of units. Zoning department won’t accept it even though it issued it. It’s mostly for real estate transactions. So you want to get the historic water records or historic permits by applying for the freedom of information request. They are definitive proof of number of dwelling units.

Added to all this confusion, the city is working on ADU ordinance so everyone who has a basement could establish a legal dwelling unit.

My summary advise would be to hold off until the details of the ordinance are released or be prepared to convert your existing space to a dwelling unit.

When you are ready, do talk to an Architect who is familiar with the codes. My approach has been to save investors from making expensive mistakes!