I can't even begin to count how many times I look at homes and discover that the owners didn't apply for a required building permit. Decks or sheds seem to be the biggest culprits and mostly fall into the "I didn't realize I needed a building permit" category. But I also find a fair amount of finished basements without required permits. These sometimes falls into the "but then my taxes would be higher" category. Yikes.
As a seller's agent, I always print out a copy of the assessor's property card before I go to visit a home. This is where I find the hidden secrets like the 3 bedroom, 1 bath home that really has 2 full baths. Connecticut law requires that towns revalue property every five years and do a physical inspection of the interior and exterior of the property every ten years. As a result, it is possible that a bathroom can exist for almost 10 years without being taxed.
Agents: As a real estate agent, you should ask the question whether a building permit was obtained for work that required one. Besides the obvious safety concerns, the taxes listed for the home, could be lower than they should be if the town is unaware of improvements like decks, bathrooms, and other finished rooms. In addition if disaster should strike, an insurance company could try to avoid paying a claim if they can prove work was done without a required permit. There you'd be right smack in the middle of that mess.
Buyers: Be sure to ask your buyer's agent to obtain a copy of the assessor's property card to be sure it lists the proper number or rooms and baths. If in doubt, the building officials office will have a file of any permits applied for on a particular property.
Sellers: Please don't ask me to pretend I didn't notice that you failed to apply for a building permit when you should have. I'm trying to avoid problems down the road for both of us. If you added a deck or a shed without a permit, go to town hall and admit your mistake. You won't be arrested or end up in jail.
When hurricane Gloria struck in 1985, I lost 2 decks when a few trees crashed into my house. I thought you could replace a deck without a permit.
Silly me.