Making a 3/2 a 4/2 on appraisal

[Blake Maloney]

Hey everyone! My partner and I just purchased a 3/2 that has two living spaces. One of them is the perfect place to create an extra bedroom, but we need to build a closet and close in a wall to make it able to be used as a bedroom. 

My questions:

-Does this usually require a permit?

-What is typically the smallest size closet that I can build to be considered a bedroom?

-Last, and most important, how do I make sure that it gets appraised as a 4/2 when we decide to cash out? (This is a BRRRR deal that we paid cash for, so we want to make sure to get the most that we can out)

Thanks a ton!