If you want someone to put a bed down there and live, then regardless of whether or not it is a completely separate unit, for separate renters, you have to bring the unit up to code (and meet the zoning requirement).

After doing your rehab, you would then want to put a renter(s) in the property, and refinance using a traditional mortgage for the lower interest rate and longer term.  

This could account for the large rate of renter-occupied households as opposed to owner-occupied. 

Overall, my experience was good , but it was a bridge to getting a long teen renter which I would also consider if I were you, may not be as profitable but maybe less headaches.

I'm thinking of getting my single family home with a 5 bedroom and 3 full bath to get a student renters.

lol) renters living here for the season that come in from other places for their season here.

You break even with renters paying down your mortgage, but the day after the loan is paid in full then the cash flow really starts coming through.

Multnomah county tax's are the highest in the state .. plus a county tax to everyone in the area renter or owner.

The house I purchased in July of 2016 in Lebanon has had a total of $143 of maintenance (winter storm) and the initial renters re-signed their lease.

I'm going to manage the property and there are currently renters whose lease just renewed.