You need to obtain a demolition permit from the Building Department. Then, since the structure is over 50 years old, and larger than 500 square feet, the Historic District and Properties Commission will be notified about your barn. We will review the property, most likely by visiting the site, and determine if the demolition should be delayed by 90 days. In that time, it may be possible to find an interested party to salvage the structure; there are a number of architects in the area who may know of projects in need of antique structures. Perhaps the barn could be incorporated into your own home expansion. Regardless, you will be able to proceed with demolition in 90 days.