Kids Web Japan

The Structure of a Japanese House


Traditional Japanese houses are built by erecting wooden columns on top of a flat foundation made of packed earth or stones. Wooden houses exist all over the world. What are the particular characteristics of houses in Japan, where there are four distinct seasons, including a hot and humid summer and a cold winter?

A gate dividing the inside and outside of a house

The Gate and Fence Dividing Outside and Inside

Some houses are enclosed by a gate and a fence or wall that runs around the border of the plot. There are various types of gates: some are made of wood and have a roof, while others have metal railings. The fence or wall may be made of packed, hardened earth, built with bricks of Oya stone (a type of volcanic rock) or made from wooden boards. In some cases, a hedge of trees or shrubs may be planted instead of a fence.

This type of fence is made from woven bamboo

Floors That Prevent Damp

In order to prevent moisture from the ground getting into the house, the floor is elevated several tens of centimeters (around 18 inches) and is laid across horizontal wooden floor beams. Areas like the kitchen and hallways have wooden flooring, but rooms in which people sit, such as the living room, are covered with mats called tatami that are made from woven rush grass. This type of room with tatami mats is called a washitsu, a Japanese-style room. Japanese generally don't use chairs on top of tatami mat, so people either sit directly on the tatami or on flat cushions called zabuton. This is why people take off their shoes when entering a Japanese house.

A floor designed to protect against damp from the ground
You take your shoes off at the genkan, the entrance to the house

The Framework Supporting the Large Roof

The frame of a Japanese house is made of wood, and the weight is supported by vertical columns, horizontal beams, and diagonal braces. Diagonal braces came to be used when the technology of foreign countries was brought to Japan. One characteristic of Japanese houses is that they have a large roof and deep eaves to protect the house from the hot summer sun, and the frame of the house supports the weight of the roof.

The deep eaves prevent rain from splashing in, so they're perfect for the rainy climate

Walls That Don't Burn Easily

In the old days, the walls of houses were made of woven bamboo plastered with earth on both sides. Nowadays, though, many different types of materials have been developed, and plywood is often used. In the past, many houses also had walls with exposed columns, but in the Meiji period (1868–1912), houses came to be made using a method that encases the columns inside the walls in order to reduce the risk of fire. In 1919, year 8 of the Taisho era, it was made a legal requirement that the walls of wooden buildings in urban areas were constructed in this way.

Rain Flows off the Roof

Many roofs in the past were covered with shingles or straw, but these days most are covered with tiles called kawara. The roof is the part of the house most affected by rain, wind, snow, sunlight, and other natural conditions. Although there are a number of differences among the roofs seen in different areas of Japan, they all have one thing in common: they are sloped instead of flat, allowing rainwater to flow off easily.

Japanese houses have developed over the years by combining traditional forms with modern technology to improve their resistance to fire and their convenience. As a result, they are no longer all like the traditional houses introduced here. Recently, though, there has been renewed interest in using traditional methods to build houses that are eco-friendly and last a long time.