Typlcally, a lender is going to lend 75% - 90% of the Cost of the project (property price plus rehab cost (scope of work)) or 70% - 75% of the ARV (As Repaired (as completed) Value).

Repair costs would be $150k.

Raleigh/Cary is what I know well, but the competition is steep.

If it costs $100,000 to install an ADU and it rents for $1,000 a month, then it may be worth it.

What is the property worth (minus the land) and separately what would it cost to rebuild? 

Meaning, if you take the money only, you would have depreciation recapture from your cost basis up to the original purchase price of the building (not including the land cost because it wasn't depreciable), plus a capital gain up to the insurance proceeds.Hope this makes sense. 

Also in Touristic cities like Paris there is a competition among tenants to get the LTR  appartment.

The larger the purchase price the greater the spread you need between purchase price plus holding costs plus rehab cost and ARV.  40k projected profit on a 600k project is too skinny for me. 

Alabama is very business friendly and there isn’t nearly as much competition there as some markets.

A friend and I created one recently:https://drive.google.com/file/...It was meant to compare costs between different lenders, but you can use it to just see costs from one lender as well.