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?
In order to avoid moisture from the ground, the floor is elevated several tens of centimeters 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. Japanese generally don’t use chairs on top of tatami, 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.
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.
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. Also, in the past, many houses had columns that were exposed outside the walls. But in the Meiji era (1868-1912), houses came to be made using a method that encases the columns inside the walls in order to reduce the possibility of fire. 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. Recently, though, people are beginning to look anew at the traditional methods of building houses, which are easy on the environment and last a long time.