First, it’s required by law. Typically, these matters come to light via title searches that are done, usually at the request of a lender during the sale or re-finance of your house are much more stringent than they used to be even a few years ago. A Title company will compare the records for Building permits and certificates of Occupancy or Completion that are kept by the Building Department with an actual physical inspection of your house. For example, a shed that has been on your property for 20 (plus or minus) years – and was there when you bought your house, but never had a permit or Certificate issued for it may not have been a problem when you bought the house; however, when a Title search is done today for the sale of your house, this non-permitted shed must now be reconciled by you, the seller even though you did not put the shed there. The same is true for things such as decks or finished basements for which there is no record of a Building Permit having been issued.
The direct answer is that if something was done in your house or on your property that required a Building Permit after 1961 when the Town of North Salem adopted the NYS Building code, by law it needs to be legalized and satisfy all applicable Code requirements. When you are selling your house this becomes an “emergency” to reconcile and after December 31, 2009 the fees for legalizing as-built improvements begin with a $1,500 fee plus the customary fees for a building permit and certificate of compliance.