They leave oil stains by their garage without cleaning up. 

Two years of aggressively paying down debt and cleaning up our credit and we finally got approved for an FHA mortgage!

@Ivan Chavez if you really want to go above and beyond: clean out gutters, inspect all appliances (or at least those you provide) ice and vinegar in the disposal, check stove elements and use oven cleaner, run vinegar or bleach through the washer, vinegar or bleach in the dishwasher, clean the dishwasher strainer, check light bulbs in vent hood and change charcoal filter, electrical system check-make sure gfci work with a tester (not the button), check all bulbs, fans, and outlets, plumbing check for leaking toilets, dripping p traps under the sinks, you can also check resistance on electrical water heater elements to make sure they aren't busted.

While it doesnt need to be a ton of the work, it does still involve liaising with tenants, cleaning the home, furnishing the home and dealing with repairs.

@Levi Dullum I agree with @Jonathan Greene.

There is a breakeven point where you can charge almost as much money for less people and thereby reduce your risk/hassles/cleaning/damages/parties/EtcYou just gotta figure out what that is for your area.... 

Hopefully your lease dictates cleaning procedures upon move out as well as showing procedures for the landlord.

Obviously the ADU should be safe and clean, but consider the cost of the upgrades vs the rent you'll be getting from your friends company.

Hello, I recently graduated college and started a business where I have been teaming up with property managers, landlords, agents ..etc to provide full service junk removal whether it's a clean out or just removing a few items that need to be removed.

Termite inspection came back clean.