Work can't begin on the Concord, Mass., barn project until permits are issued, so it's off to Town Hall to discover how many the crew will need. Meanwhile, carpenter Norm Abram and preservation architect Leonard Baum explore the barn's history. On “Ask”: “Housecall” projects include a shaky newel post and an elderly hot-water heater. Also: crewmembers guess the uses of unfamiliar implements. Kevin O'Connor hosts.