ARV via finished basement + bathroom?

[Account Closed]

Hello,

I'm looking to BRRR and have found a foreclosure house. In addition to other changes, I would be finishing the basement and adding a full bathroom in the basement (currently 1 bath in the house). I would get it all properly permitted.

I've been told many times that the appraisal won't reflect much for finished basement and/or below grade bathrooms. However, I do know that some credit is given.

How can I determine ARV related to finishing a basement and adding a bath down there? I know for rental purposes it should be helpful..