But once you have the layout done, it’s just busting concrete.  

Honestly, they aren't for me so I have done one.I think to start, you need to layout a sort of budget (if you haven't already --- this is as public board so we don't need to know). 

., Hapeville, GA 30354I've spoken to SketchHaus and an independent architect and it's averaging around $4,000 - $5,000 including the layout and plans to have approved permits.

Additionally, exploring alternatives like legalizing the existing cellar apartment, if applicable, or renovating the current layout to increase rental income could be viable options.

A garage I can convert, awkward layout I can reconfigure, etc.

But we had to submit plans with it labeled as an office, because my jurisdiction requires bedrooms to be 150 sq ft, and my office (due to moving a wall) is 135 sq ft.More importantly, I think this layout would turn off a lot of people.  

So you may need 20k to close on a house and then another 15k - 20k to lay out to a contractor for 60 days. 

The layout is very convenient that I can easily put a wall where there is a door separating 1 bed and 1 bath (master bedroom) from the rest of the unit.

For 4-5k/unit you can probably just get hookups in the actual unit provided the layout allows. 

The property is nice but the house layout is not ideal for a rental.