I think what you are looking for is something like:
Coldwell Banker Burnet
licensed MN Real Estate Broker
It's true that an appraiser will value below ground finished square footage @ half the value of upstairs finished square footage.
Even with a walk out basement with windows on three sides, if one wall is bermed by earth then this is considered basement space.
While I don't know if there is a 'regulation' determining this valuation, there is language on the appraisers form that will denote basement from 1st floor finished space and how this space is valued differently.
In the real estate industry, in order for something to be considered as part of the 'finished square feet", the included spaces need to have the walls covered and finished with some sort of wall covering such as paint, wallpaper, wood paneling, etc. The ceilings are the same...and those usually mean "painted". Also, the floors need to be finished, not concrete...and not painted concrete. Usually, floor coverings like wood or carpet needs to be there.
Additionally, to be counted as a bedroom, a room must have a window and a closet. If it doesn't have one, the other, or both, it's not considered a bedroom, but still could be included into the finished square feet calculations.
I hope that helps.
If your home is in Minneapolis, check with Minneapolis Development, 612 673 3000.
There are permits by category, but not for basements in general. It would depend on the age of your home, type of construction, and if you have full or partial excavaton. Sometimes the heating and plumbing systems were run through the middle of the basement making finishing more complicated than if they were tucked into a corner.
When there are properties ranging from the 1880's through 2012, it is impossible to generalize. "Typically," could only refer to like properties. A general contractor could give you an idea of what you could do.