Most of our units in Central Texas are running HVAC, water heater, microwave and stove on 100A service.  

You should be getting rental income from the other units.

I myself back 15 years ago was involved in a running legal battle with the HOA of a unit I obtained ownership of by note foreclosure.  

I have a 8-unit apartment bldg in Urbana, IL.

So, I am in the middle of purchasing a co-op unit for a flip.

Maybe even a 7th bedroom /w bath by converting part of the garage.That kind of modification might hurt the resale appeal to a future owner-occupier, but let me tell you, it's STR gold. 

We're going to start the mid-term rental route for our unit upstairs.

My understanding is that assuming that one has no debt other than the mortgage for the first househack, it is calculated as(PITI1 + PITI2) / (Monthly Paycheck + 0.75*Rent1 + 0.75*Rent2)Rent1 is the total rent collected from the first property assuming that you have moved out and have fully rented it, and Rent2 is the rent collected from the other units in the new multi-family property that you want to buy.Is this correct?

Hello, I am currently under contract on two duplexes (4 units) and am set to close next week.

I do live in my building so my income from the other 2 units in the building go toward my mortgage payment.