To me that would be simpler and also eliminate any additional expense to generate and record any additional documents. 

@Brandon Sisco Agreed 85% is available but there are a few more requirements to get the extra 5%

Subdividing the lot would add an additional $20k in expense as I would need to tap city water/sewer to the new duplex (previously the detached garage apartment).

The property cash-flows at about $1200 after all expenses.

STR regulations and taxes are becoming harder there, and properties are pretty expensive!

I'll assume you don't know this, but you should require every renter to have you as an Additional Named Insured on their renters insurance policy for the same reason you want to get a Certificate from a contractor doing new work. 

You also need to verify the requirements of the city you live in as to AirBNB and such.  

It did not require a significant amount of out of classroom time and you can go at your own pace and timing.

It's very easy to book a quick flight to Mexico at the taxpayer's expense and go and check on what's going on the ground.

@Avalon Guenther I'm right outside of Ann Arbor, and there are a couple of great local resources that don't require you to drive an hour away.