You are aware what your proposing is illegal in MN, more than likely by 3 or 4 ways.... 

The City Council meeting was cancelled due to weather because even God thinks the proposal is a stupid one and is trying to prevent it from becoming law.

(the house across the street just got sold and is set up wonderfully for this sort of thing - the new owner has already expressed an interest in short-term rentals in general, fingers crossed he'll be willing to accept my proposal of letting me rent some/all of his space!)

@Marvin Robinson What you are proposing is tying up the lot, then marketing it to find a home buyer that would obtain the financing for you to build the house.

Applicants for short-term rental licenses from the city must have the proposed short-term rental inspected by a code enforcement officer and pay a non-refundable application fee of $50 and an annual permit fee of $500.

In the middle of all of this too I was getting ready to propose .

I am considering making a proposal to an owner with a similar scenario.

The proposed ADU would be retrofitting an existing attached bonus room.

If the contractor admitted an accounting error, and is willing to produce detail cost documentation, and proof of scopes of work attached those costs per unit fully completed, then compare that against your original estimates or proposals, see if there any truth in your eyes to their claim.

I'd be wary of any proposed solutions that do not also address the root cause.