One of the most prominent features of Tudor and medieval architecture is what is called “half-timbered houses.” The editors of the Encyclopedia Britannica describes “Half-timber work” as a, “…method of building in which external and internal walls are constructed of timber frames and the spaces between the structural members are filled with such materials as brick, plaster, or wattle and daub. Traditionally, a half-timbered building was made of squared oak timbers joined by mortises, tenons, and wooden pegs; the building’s cagelike structural skeleton is often strengthened at the corners with braces. This method of timber framing was adapted to both low, rambling country homes and six- or seven-storied buildings in crowded towns. In England it was popular in regions that lacked stone as a building material. It was used in England in the southern counties and the West Midlands, especially, from about 1450 to 1650.

“The wooden frames of 13th- and 14th-century half-timber structures were often elaborately ornamented. Exposed ground-floor posts were frequently carved with the images of patron saints, whereas other framing elements were enriched with delicate running patterns. In France the latter emphasized the vertical elements, and in England the tendency was to stress the horizontal lines of the structure. During the 15th and 16th centuries, the decorative contrast between the dark timber and the lighter filling was fully exploited. Panels between the studs were made of brick in herringbone patterns or of plaster molded or incised with floral forms or with inlays of slate, tile, or marl. Carved ornament was lavish and fanciful and showed classical motifs. Many wooden members were added without structural necessity. These were often crisscrossed under windows, and in England, where more timberwork was exposed, they were assembled in cusped shapes or chevrons to create the striking patterns of the “black and white” manor houses of Cheshire and Lancashire.”

 ThoughtCo provides us a look at the history of this method of building. “After 1400 AD, many European houses were masonry on the first floor and half-timbered on the upper floors. This design was originally pragmatic—not only was the first floor seemingly more protected from bands of marauders, but like today’s foundations a masonry base could well support a tall wooden structures. It’s a design model that continues with today’s revival styles. In the United States, colonists brought these European building methods with them, but the harsh winters made half-timbered construction impractical. The wood expanded and contracted dramatically, and the plaster and masonry filling between the timbers could not keep out cold drafts. Colonial builders began to cover exterior walls with wood clapboards or masonry.”

Half-timbered indicates that the logs are halved or cut down to a square. In half-timbered buildings the walls are filled in between the structural timbers. Most commonly this infill was wattle-and-daub (upright branches interwoven by smaller branches and covered by a thick coat of clay mud), laths and plaster, or bricks. 

http://www.robertharding.com The 15th century half-timbered Black Swan Public house, Peasholme Green, York, Yorkshire, England

To accomplish this, first stone or brick is set to serve as a footing around the perimeter of the house. Into that, a sill beam is placed on the foundation. Then upright beams are set with mortar into the sill beam and tenoned at the top into another horizontal beam. Think of this is like building blocks. One box is set upon another to create multiple floors.  

Britain Express tells us, “Often the upper floors project out over the lower ones. There are several conjectures as to the reasons for this. One is that houses in cities were taxed on the width of street frontage they used. So a high, narrow house saved the owner money, yet to maximize interior space the non-taxed upper floors were lengthened. Also, the projecting upper floors helped protect the lower house from rain and snow in the days before gutters and down-pipes.

Tudor half-timbered buildings in Exeter Historic 15th century buildings in West Street

 “By the 15th and 16th century timber framing began to be exploited for its decorative qualities. Timbers which had minimal structural importance were added to the frame, to enhance the decorative effect of dark wood set into whitewashed walls. The Jacobean period saw this use carried to extremes.

“The construction methods used in half-timbering allow buildings to be easily dis-assembled and put up again elsewhere. This has helped salvage houses which would otherwise have been destroyed to make way for new development. Many medieval timber-framed houses have been re-erected at open air museums such as the Weald and Downland Museum at Singleton, West Sussex, and the Avoncroft Museum of Buildings at Bromsgrove, Worcestershire.”

Resources: 

“Half Timber Work,” Encyclopedia Britannica 

“Half-Timbered Houses,” Britain Express 

“What Is Half-Timbered Construction,” ThoughtCo