The difference between timber frame and post and beam construction is the way the individual parts are connected: timber framing uses wood joinery and rarely uses steel parts; whereas post and beam structures are connected with metal fasteners and connectors.
Benefits of Post and Beam Construction
Post and beam building generally has lower-skilled labor costs than timber frame construction. Although post and beam structures require plenty of labor, they tend to be less complex in terms of engineering, construction, and fabrication.
Disadvantages of Post and Beam Construction
Moisture can condense on steel surfaces causing the steel to rust and the surrounding wood to decay. Depending on the complexity of the metal plates, can be more expensive than traditional timber framing. Dissimilar materials (metal and wood) tend to work loose over time.
Benefits of Timber Frame Construction
Usually (but not always) more attractive, elegant, and expensive. Traditional wood-to-wood joinery, if kept dry, can endure for centuries. Finally, traditional wood joinery is somewhat elastic–in other words, it can deflect and give a little under loads. This is one reason that certain examples of Japanese architecture have survived for over a thousand years–despite the destructive earthquakes that occur several times each century.
Disadvantages of Timber Framing
Timber framing has a higher cost of skilled labor to design, engineer, and fabricate traditional joinery. Some increase in timber cost when timber sizes are increased during engineering to accommodate joinery.