Process of Legalizing a Garden Unit? Chicago, IL

[Robert Trevor]

I read through the coding and zoning and the ceilings are 8 feet tall, it’s hardly below grade, has 2 legal bedrooms with a window and closet. 

2 exits 1 front 1 rear

the hang up I see is the windows, there’s only about 40sqft of windows, compared to the 1,000sf of habitable space. 

Has anyone had any experience around this condition or will it be nearly impossible to overcome?

2 Flat Zoned RT-4 Chicago IL