would this be an architect? 

Paid agent commission, architect fee, builder consultation and estimate, survey, soil test, HOA, property tax but the final construction cost could not be supported by that market.

I hear people talk about having a business plan that they take to the banks or lenders to show what they plan to do with a property.i was wondering who is that person that writes up the business plan is it yourself, a developer, architect, a numbers guy or is it all of their information put in a booklet to give to the bankers for the loan.

Land $10,000, due diligence / soft costs $3000 (oversees architect and engineering), $1900 to remove from flood plain / get survey, the house is 700 sq ft which the floorplan is below.

We bought the lot, had an architect design the building and contracted for the construction.

FYI: If you call an architect or GC and tell them you have this "brilliant never before considered" idea of turning offices into apartments, the architect will eye-roll so hard that they risk permanent blindness. 

How does one figure out what is a fair fee to pay architects? 

@Justin R. yes my understanding is a companion unit may be attached or detached...I was more trying to focus on the fact that if these are companion units (attached or detached) that OO is not a requirement.You probably have more practical insight on this as I usually recommend clients don't need my help, and their architect probably is capable for items like this.

The same principle applies to your finances, and a knowledgeable accountant can be the architect of that foundation.

Aside from wanting to invest in real estate, I am an architect and landscape architect.