When we run into walls, we look for easy ways out.

You should either buy with a DSCR up front if the property is eligible and self fund your rehab or hard money for acquisition, do most rehab to common areas with the exception of additional walls prior to refinancing into a long term DSCR loan. 

Megan Luckily the math part isnt too high level just addition, subtraction, some mulitplication and division but we as a community can all help you through it.Leave the complicated math for the wall street quantative analysts and derivative traders.

And the wall is built on top of that wood.

The biggest mistake new investors make is to walk a property, maybe explain in general terms what they want and then let the contractor come up with the SoW.For a bedroom this could be:- replace carpet- repair closet dooror- remove carpet- remove curtains, nails and screws- replace closet doors, entry door SKU#- replace window SKU#- refinish hardwood floors 144 sqft, clear/oil-based- prep and paint all woodwork- patch walls, texture, paint walls eggshell white clay, ceiling flat white- replace light fixture SKU#, replace lightswitch w decora/white, replace 3 outlets&covers- install blinds SKU#Obviously, the cost would be quite different.

It's technically not an ADU if it's the only property on land as it's an accessory dwelling unit to a main unit.

Know that the market you're serving does exist, and is like an underlying current that's being held back by walled garden that the government has only recently scrutinize.Zillow, Redfin and Trulia has all attempted at disintermediation and increase market efficiency, but failed due to the market powers that maybe. 

Not the best asset class for Wall Street to fleece the public on =)

Paint the walls.

Quote from @Jaron Walling: Without getting to political I'd say no.