More specifics. Are you replacing tub or shower? Changing any plumbing in walls/floors etc. ? Does the electric meet code (outlet(s) which are gfi protected). Is. There ventilation?
Is any structural happening ? New walls, insulation, windows?
Probably yes - and it's not a big deal at all to get a permit. And when you sell, you won't have problems with then needing to file and get permits
Sweetsnuggles