As for title searches, note that timing can depend on the state and how "modernized" the local municipality is.

It has been 100% hands off since we did some basic work on the house to clean it up, make it safe, and make it look fresher and more modern.

New roofs, painting the building a new modern paint scheme, interior upgrades and upgrades to the grounds & amenities.

Modernize the whole rental so we can rent it for top rents.

Inside I painted the entire place to give it a modern clean feel, added a kitchen island w/ butcher block.

Johanna,American Modern Home I believe will write it also.

You need to find an old water bill like back in the 1950's old and if the water bill says "3 unit building" the city will give you a new zoning doc that says legal 3 unit and the city will not even come to the building or look at exits, modern code, etc. all they are doing is "correcting the zoning doc" grandfathering it in. 

For example, I'll want 50,000 units near college campuses in different states or own commercial property that can be remodeled into these new modern developments and have one in every state.Sounds crazy but those are two of my main goals. 

If it is the latter, having the original structure built with permits is important because that can exclude you from the modern setback requirement among others. 

SFH probably have the best comps and arguably more equity but comes at a cost of lower cash flow and few doors. 2) the top floor is an "economy 1B1B" as was an attic and is less appealing. 3) the whole building does not have HVAC and to bring to modern standards, 3 HVACs sounds $$$. 4) Don't have to remodel a 3rd kitchen.Problems of changing to a duplex?