So,  I recently had an offer accepted and I'm planning on some light rehab. 

The building's historic nature (I don't own any properties with structures less than 100 yrs old), its prime location in an upcoming part of downtown Jacksonville, and its price.

It was not done well, there is a hodgepodge of 'handyman/diy" work throughout, and I'm trying to decide if we fix it up right or just make do until we sell in 10-15 years.The two units are ~3bd, 1ba and about 950 SQFT each, with less than ideal layout but otherwise are ok cosmetically, and the property is fairly large and has a nice yard for the area (South Seattle near Light Rail).

Finished the kitchen out, moved a closet from a guest room with 2 closets over to the primary bedroom so primary has 2 closets, and refreshed all paint/light fixtures.

Improved all lighting and electrical in the house.

Interested in hearing more myself - have been toying with the idea as the yields seem high, but naturally cars (unlike real estate) do not hold their value. 

@Ben Healy I would be concerned about a Heloc to buy a hold because of the nature of Helocs. 

You buy the house and renovate it (if you want conventional financing, you probably need something that only needs light rehab work). 

@Landon Bleau is right...it's not about the number of units but about the SF...plus add for the extra kitchen and bath(s)And your numbers look a little light to me.

Maybe low flow toilets and new low flow shower heads, LED lights, rainwater capture system and cistern to use that for landscape watering.