This barn used to be the carriage house for an adjacent property, and was initially in pretty bad shape: no roof, sagging beams, and so much Redwood duff and ivy that the owner didn't realize there was a concrete floor underneath. A framer helped the owner reframe the barn from the inside, using dimensional lumber to keep the integrity of the original studs. (Back in the day, a 2 x 4 actually measured 2" x 4".) The siding seen here was originally on the inside of this same wall. Originally the barn had three "rooms", and when the third room collapsed the wall was replaced with plywood.