All Forum Posts by: Jack Smith

For anyone curious, I found the answer. While the phone is rarely answered in the Department of Buildings of Chicago, their website does have useful information. According to the code clarifications they have posted, ground floor retail space is considered an auxiliary use, therefore section 13-48-100 shall not be applied to ground floor retail space. The building, however, must meet the height and area restrictions for a residential use of the intended construction type.

I have a question regarding bulk and density standards of business and commercial zones in Chicago. Specifically, a lot zoned B3-2. In this case, a minimum lot area of 1000 square feet is required per each unit. This is pretty straightforward, but if someone was to build residential units above the ground floor retail unit (permitted; and no ground floor residential units are permitted in the B3 designation), would the retail unit on the ground floor count as a unit when considering the minimum lot area per unit rule? If that is confusing, would a 2,500 square foot lot zoned B3-2 (community shopping district) be restricted to one ground floor commercial space and one upper floor residential unit, or could a developer build two residential units? I can't seem to find anything specific to this in the Building Code (See Chapter 17-3 for further reference on bulk and density standards in business and commercial districts). Thanks anyone for your help.

Jack

FYI:

This is the published code applicable to my question:

"17-15-0303-A Except as otherwise expressly stated, the Zoning Administrator is authorized to approve an administrative adjustment allowing a nonconforming use to be expanded into another part of the same building, provided that the Zoning Administrator determines that such expansion:

1. will not result in a violation of off- street parking or loading requirements; 2. will not violate any applicable bulk or density standards; 3. will not result in greater adverse impacts on the surrounding area; and 4. is not expressly prohibited by Sec. 17-15-0303-B." Hope this helps, John

Hi Brianna,

Thanks for your reply. That is pretty much what I expected to hear. The Chicago zoning is quite difficult, but I feel that spending the time to get to know it can really bring you a competitive advantage. I have done a little more digging this morning, and after speaking to a representative of the Office of the Zoning Administrator, I have discovered that as long as each unit is legal (and that it can be documented), and as long as you do not exceed your maximum floor area ratio specified for the lot zoning type, then there is no restriction on the expansion of the unit. Even just typing that is confusing, I know, but there are some good resources available for anyone with similar questions. I would start by reading the City of Chicago Building Code, at least to familiarize yourself with the rules regarding what you are trying to accomplish.

I run into this problem often in Chicago. A three flat building also has a full unfinished basement or a bit of attic space as well. I would like to duplex down the first floor unit into the basement, or duplex the third floor unit up into the attic. The basement is below grade; so it would not count against my floor area ratio. That would leave me with some square feet of usable space in the attic. The building is zoned RT-4 in Chicago, and as far as I can tell, there is a minimum requirement of 1000 square feet per dwelling unit. The problem is that the lot is only 2500 square feet. Therefore, at least one of the units in the building is non-conforming according to the current zoning. The building is well over a hundred years old, and all three units are legal. But, can I expand a legal non-conforming use unit? Even if I am not going over the floor area ratio for the lot, does the fact that the lot itself is not large enough to support the density of a third unit prevent me from making use of the additional space? I can't seem to find any applicable literature, beyond the building code saying that you cannot expand non-conforming units. Any help would be appreciated. Thanks!