Fifth bedroom or second kitchen?

[David Matthews]

Hi all, I have a 4bed 3bath single story ranch home with a basement. Upstairs is 3/2 with a primary en-suite bathroom and two beds that share a bathroom. There is a kitchen and living room on top floor.

downstairs is a 1bed 1bath with living room, office, and second kitchen. I was thinking the other day... is it more valuable to have this second kitchen / basement apartment OR, rip out the kitchen for a fifth bedroom? I mean specifically from an appraisal perspective, not potential rents. 

to be clear - there are many homes in the area that are 5/3 so this wouldn't stick out.