Experiencing Traditional Japanese Architectural Techniques (1): “Kigumi”

What is “Kigumi”? Traditional Japanese Architectural Techniques

“Kigumi” is a traditional construction method in Japan that is said to have been used as early as the Heian period. With minimal use of metal fittings such as nails, it is a highly precise technique of building structures primarily using wood. By intricately carving and processing the ends of the timber, they are fitted together tightly to form a sturdy framework.

Characteristics of “Kigumi”

Despite the minimal use of metal fittings, buildings constructed using “Kigumi” exhibit high durability and seismic resistance. Unlike modern machine-cut timber, “Kigumi” involves hand-carving along the wood fibers. As a result, the wood retains its strength and resilience, making it a highly durable structural material.

Furthermore, since it does not rely on nails or bolts for connection, “Kigumi” joints may have slight gaps. These gaps effectively absorb seismic forces during earthquakes, allowing the structure to withstand tremors. “Kigumi” can be considered a technique well-suited to Japan’s earthquake-prone environment.

Examples of “Kigumi” Architecture

One of the most famous temples in Japan and a UNESCO World Heritage Site, Horyu-ji Temple, is renowned for its construction using “Kigumi.” Maintaining its beautiful appearance for over 1300 years, it boasts exceptional longevity among wooden structures. Traditional techniques have been preserved, and regular inspections and repairs have been conducted.

Another example is the five-story pagoda. Typically constructed using “Kigumi,” it features a central pillar called the “Shinbashira,” a thick and long column. The walls and eaves visible on the periphery are not joined to the central pillar but are left with gaps. During earthquakes, the entire structure sways, allowing the components to move freely and absorb the shaking, preventing collapse.

This technique has also been applied to the construction of the Tokyo Skytree, demonstrating that “Kigumi” remains a highly relevant and effective technology even in modern times.

Types of “Kigumi”

There are over 200 types of “Kigumi,” with subtle variations depending on the era, region, and craftsmen. Broadly categorized into “Tsugite” for connecting timber end-to-end and “Shiguchi” for arranging timber at right angles or diagonally, these joints may include components such as “Dabo” or “Shachi” to prevent slippage and pegs to prevent withdrawal.

Let’s Touch “Kigumi”

At the Kigumi Museum, visitors can experience “Kigumi” hands-on. I’ve tried it myself, and engaging with “Kigumi” is truly enjoyable, like solving a puzzle. Let’s touch on “Kigumi,” a traditional Japanese architectural technique. Why not take a closer look at Japan’s traditional architectural techniques and experience them firsthand? This wonderful experience will surely become an unforgettable memory of your trip to Japan.

Explanation of Traditional Japanese Timber Construction Terminology

“心柱” (Shinbashira) – “Shinbashira” refers to a large pillar placed at the center of shrines, palaces, or temple pagodas.

“継手” (Tsugite) – “Tsugite” is a general term for structures that join two parts in the same direction. In woodworking, it refers to joints used to connect timber.

“仕口” (Shiguchi) – “Shiguchi” is a structure where two or more pieces of timber are firmly joined together at different angles (often at right angles) to form a corner.

“だぼ” (Dabo) – “Dabo” is a small piece inserted into holes drilled into the joining faces of timber pieces to prevent misalignment when they are joined together. In English, it’s called a “dowel.”

“しゃち” (Shachi) – “Shachi” is a shortened term for “shachi sen,” which is a part used to reinforce the joints of wood. “Shachi” is characterized by being driven diagonally into the wood grain.