Timber framing is a nearly obsolete system for creating the structural skeleton of a house. (It still appears in today’s “timber” or post-and-beam houses, albeit with a reliance now on metal fasteners.) Timber framing was used in Europe since medieval times, and is the basis for English half-timbered houses (where the structural timbers show on the filled and stuccoed exterior). In a timber-frame building, the entire weight is carried by massive beams and posts; wall sheathing is just a curtain to keep out the elements. Timber framing was the basic technique for building wooden houses in the U.S. from the 1600s until the middle of the 19th century.
The timber frame was hand hewn. In the early days, all of the framing timbers were felled and squared up by hand. Even after the advent of power sawmills made it possible to make square timbers by machine, all of the notching for the rather sophisticated joinery was still done by hand. Housewrights would develop their own special cuts for making joints and connecting timbers; the old houses have ingenious combinations of mortises and tenons, dovetails, and other joints.
It’s impossible to tell from the exterior whether a house is an early timber frame. But there are telltale signs inside. The posts and summer (i.e., large, central) beams are so big they often protrude from walls and ceilings. These massive timbers were often encased in smooth planed boards with beaded edges. Later generations of “restorers” typically removed the casing to expose the rough framing timbers, a practice that may have horrified some fastidious early occupants.
The timber frame made a strong and durable house. However, the advent of lighter balloon framing (using machine-sawn lumber and iron nails) made the old practice seem expensive and it quickly fell out of favor with builders. Timber framing has been a popular subset of custom new construction since the 1970s.
Half-timbering refers to a structure with a frame of load-bearing timbers, creating spaces between the timbers called panels, which are then filled in with a non-structural material. The infill is known by different terms in different building traditions (fachwerk, bousillage, etc.), and is typically parged or stuccoed over. But the large framing timbers often are left exposed on the exterior. Revival houses of the 20th century have decorative “timbers” that were applied to the face of a modern stick frame.