If you add an addition, garage, etc then they will reassess.

My plan so far is to go knock on his door and ask him if I can take pictures and just check the place out because I've never been in his half. 

Somebody comes and knocks on the door and asks to look at the house.

Most of the investors I work with shoot for $150-$200 a door, so you make that much with a property matches up and you're getting to cut living expenses for a year.

So that opens up the door to just run this thing out to the endzone myself here and save the commission (could probably even use it as a bargaining chip in negotiations).The issue is that I don't really know that much about the finer details of being a buyers agent (even having bought multiple houses before).

In the situation you're describing it take me 4 days for a 2 bedroom 1.5 bathroom unit unless I'm replacing floor covering in which case it's usually a full week and maybe almost 2 weeks.In 4 days, worst case 5 days, I can get a thorough cleaning and painting, inside and out, even removing doors from hinges if needed.In that time window I can also have a plumber replace a faucet or an electrician replace a bathroom vent fan, minor stuff, if needed.

Average Turnkey Cash Flow Per Door In Phoenix Metro Area No Bank Neededhttps://www.biggerpockets.com/forums/600/topics/584916-average-cash-flow-per-door-in-phoenix-metro-area

Sliding hidden doors whenever possible instead of swinging doors. 

I am building more 14x50 storage units with the doors facing the existing doors.

I invest in multi families personal so I could give you many reason why it is the best avenue (economies of scale, discounted management, more doors with less transactions cost, etc).