The project: the Carlisle, Mass., farmstead. Work is completed on the air-conditioning systems and continues in the master and kids' baths; lighting is installed in the kitchen and the storage system is installed in the barn-basement workshop. Also: the terrace's teak furniture arrives and the pine stair treads are stained. On “Ask This Old House,” projects include a backyard ice-skating rink and clearing a clogged vent stack with a fiber-optic plumbing snake.