It sounds awful but it will be the buyer’s headache. I live in WA and we were under contract for a house that had an attic conversion. During the inspection part of the process we requested records of the permits for the work done but found out it was unpermitted. Went to the county to find out how to rectify and we would have been on the hook not only to get it retro permitted but also to pay 18 years in back taxes with interest since the addition impacted taxes and value. Obviously we walked on the deal.

Basically if no one says anything during the buying process then nothing happens. Just depends on if your buyers care or not.