Deconversion vs Duplex Up and Basement Unit to keep as a two flat

[Peter S.]

Chicago market specific, please.  Northcenter

I have a traditional 2 flat with a basement. Two apartments + unfinished basement.  Back stairs for second exist. Two separate gas meters, electric.  Electric panels are currently in the basement.  

I have a few questions please, and feedback is appreciated.  I just asked an architect, no answer yet, and would like to compare his answer with feedback here. 

Goal is to remain as MF for tax and have future flexibility to use or rent the basement unit.  In the immediate future, we won't rent any units here. 

Can we duplex up to remove the back porch stair and call the basement a future apartment without going the "deconversion" fee ( $15,000) and future tax disadvantages?  We have tax write offs if we ever rent this thing, unlikely, but there opportunity is gone if we call it a "deconversion".

Does this require a zoning change, etc.?  

Will the basement unit be considered an ADU? Note that we are going from 2 flat to 2 flat, although the unit moves down.

Do we need to finish the basement unit ?  If not fully finished, we can even get more tax discounts as a disabled unit. That's legal and we have done it before while rehabbing our other units.   This is not a trick, I just don't have the money to finish it. 

Second exit to the basement would need to be provided.  We have a side option. 

Utilities.   Do we need to give the basement unit their own gas and electric -  or at least all electric- , vs. can we include all utilities in the "rent", if we ever rent it or Airbnb?

Panels. I assume the electrical panels can't be in the basement unit unless is a "common space".  What about water heater, furnaces, etc.?   I can build a "common space".

Stairs to basement.  Can stairs be added to the basement from the first floor?  We can add a "door" with a lock to separate the space. 

Thanks a lot,