I would also have to say that you can find cash flowing rentals both places for 20-25% down, but they certainly aren't falling from the sky; an asking price is just an asking price and you need to be able to act very quickly when the right one comes available so get a pre-approval from a lender before you start looking seriously.Brick and stone are preferred facade materials for heat reflection and wind resistance.

Section 8 or the voucher program is based on qualified already approved voucher holders.  

(Most likely)2) how likely are they to approve it?

You need to own or control the lot or get approval from the owner to market a lot and house package especially if it’s going to be listed in the MLS.

You need to know who is lending on deals, and who is not, and you also need to know their underwriting criteria for approving the loan.

What were the terms and stipulations - Got pre-approved for this through my mortgage broker not a bank. 

They have not done a consolidation as they will not get approved and his father has a gambling problem. 

Im approved for a multi unit purchase.

That's not legal advice as I'm not a lawyer, but I think the situation is pretty clear cut.The issue I see is that your friends have already incurred these expenses without giving the landlord the ability to mitigate his losses, nor did they get approval for any of the costs beforehand.

One thing you can do is to check out the contractor's other ADU builds, you can see the quality as well as ask for permit and final approvals of those projects to verify.Good luck!