So after that, I kept a careful eye on the number of residents living there, and water usage actually went down.So before you go crazy about residential vs commercial, sub-metering etc, have these issues checked out.

Do you currently own a primary residence home?

(We have visited all the continents and 108 different countries)I learned the following at a very early age:If owning one house was good, owning 10 houses was better.If owning 10 houses was good, owning 100 houses was even better.I continued that trend and I believe four years ago, my wife and I went over the number 1000 in single-family residences we have owned or built in our lifetime.

Within the next year, I can see purchasing a new house for primary residence.

I managed a single rental during my medical residency and even that was a headache at times.

I don't really understand what you mean....The best "tweak" I know for a primary residence is to use a FHA 203k loan. 

I have a primary residence that may be a cash out refinance candidate. 

For me it's kinda worth it because I'd clear about $1,800 a month once all the units are occupied with paying residents.

Why do you plan on owner financing when you could get a Conv or FHA loan for a primary residence with 3% or 3.5% down? 

I wonder if there is a service one could subscribe to or access which shows:- Total value of residential mortgage debt in the US- How that debt is grouped by fixed vs ARM rates- How thar debt cuts in terms of prime vs subprime- How are the monthly payments doing (on time vs late)- Proportion of foreclosures (growing or declining) - How much of the debt is primary residence vs investment - Average loan to value estimate My point is simple.