The proper way to approach this appraisal problem is (summarized below):* find reasonably similar comps - find relatively recent duplex sales in the Subject's market area and adjust for differences, based on market response (i.e. how much more/less buyers would typically pay for certain characteristics like size of units and lot, location, quality/condition, etc).* In the absence of similar comps - go back in time to find any similar comps, no matter how long ago and adjust for market trend differences (appreciation, etc), as well as other adjustments as typical (size, bed/bath, condition/quality, location, etc).* Go to nearby market areas/neighborhoods and find reasonably similar duplex sales and adjust for market area/neighborhood differences as required - along with the other adjustments.* Find reasonable 3 or 4 unit (not more than 4, and they can use sfr's, but those are typically not as good for comparison.

If the problem is something related to the property itself or rent payments, then it is the responsibility of the landlord to address.Anything outside of that a landlord should avoid or proceed with great caution.Tell your tenants your hands are tied and you need them to help you to help them and call the police so you can also file complaints with the city.

For me personally, I've been in the niche since 2007.

Joint Ownership with a Formal Agreement: Another option is to keep the mortgage as it is but create a formal agreement where your sister-in-law is no longer financially responsible for the property.

I'm personally not a fan of no cash flow.  

. 🤷🏽‍♀️ Im not the only person that has this issue.

I have maps and basically every address that is legally zoned memorized in the County (except NSB), @Cory Cannon, Daytona is definitely enforcing, many that you see in city of Daytona are condos or just haven't got hit with the fine yet...IMO not worth the risk in city of Daytona at all...unincorporated Volusia maybe but I personally know at least 15 of those that got in trouble too. 

There are generally some negative consequences with all adults not being named on the lease as a responsible party. 

If you can't keep control of your personal finances, you are highly unlikely to succeed in real estate investing.

I would appreciate any information.I'm not sure how much should I trust the RE person, it's in his interest to sell me the place.