Your son is responsible for making payments on time or ruining this seller's credit. 

If so, then yes this is quite a solid option.

Couple hundred bucks a door monthly cash flow, solid ROI, and yes plenty appreciation (#1 appreciating city 2023).

Hi Dominic, thanks for the detailed response.

You could look for properties that are already getting solid rents in one of the units. 

I would also explain that if it happens again that they may be responsible for some or all of the cost.

Solid ROI.

Some of them even walk off the job, even after they pull permits and are technically responsible for the work.  

Have every detail spelled out, use an escrow account and daily updates verifying all parties are executing their responsibilities.

I believe it is completely reasonable to have a clause in your lease that places a cap on utilities with any overage (proven by a bill) being the responsibility of the resident.Our clause states that any electrical bill (we don't have gas, and water has never been a problem) that is over double the same month's bill from last year will have the overage assigned as a fee.It is important to keep your bookkeeping straight if you do assess a fee.