In the case of improvements, you may need to be aware of any code violation or open permits, and in some cases no permit obtained at all, for improvements performed by you, prior homeowners or a contractor.
Also, keep in mind that in areas and cities where the homes are much older, work done at that time may have been performed to code and a Buyer can’t expect you to completely redo an improvement just because the code has changed since that time. The same is true for Turn of the Century homes where permits may never have been pulled for things such as additions and finishing basements. It’s not against the law to not pull a permit for work being done. It’s just a safe measure that a Buyer knows any improvements to the home were done according to the standards set forth by the Regional Building Department for that County.