Denver Property Type change from SFH -> Duplex?

[Michael Ernst]

I have a property I'm looking to close on soon in the Denver area that is listed in a SFH zoning area. The interesting part is that this property:

1. Property type is SFR Grade C

2. Has 2 valid addresses according to USPS but only 1 is actually associated with the house

3. Both addresses were used on the house since at least 2019

4. Has full separate entrances

5. Has full Kitchen in the basement unit

6. Has 1 conforming and 1 non-conforming Bedroom in the basement

7. DOES NOT have separate Heating/Cooling.

8. Several other properties with this exact layout and in the same zone have the property type: RESIDENTIAL-DUPLEX

So I guess my question is this:  If I were to go through the trouble of putting in a new and separate heating and cooling unit for this property as well as adding a new power meter for the basement unit, how hard would it be to get this property labeled as a Duplex from a Single Family?  

Anyone who has done a SFH -> MFH in the Denver area with some insight would be a GREAT help!

Thanks!