This is an essay on Japanese traditional architecture style.
Gassyo Zukuri Style 合掌造り
If I think of a typical unique local style in Japan, I think of Shirakawago House at first. Actually the style is called “Gassyo Zukuri”, they coined the name coming from the steep rafter roof looked like one’s prayer hands together. It is not in my neighborhood, but it is in Gifu prefecture. This style itself was registered as UNESCO World Cultural Heritage in 1995, and the villages that have this style houses became popular tourist spots.
Shirakawa and Gkayama villages are most popular Gassho-style sites for visitors. According to the Wikipedia, for example, Shirakawa village has only about 1,933 residents in a density of 5.4 persons per square kilometers. The total area is 356.55 kilometers. Most of the part is rice farms and mountains. Most of the people are farmers, but now some of the houses became guesthouses (with Japanese hotel style), and museums for visitors who want to learn about the Gassyo Zukuri housings.
There is not much evidence, but it is said that during the Heian period (794-1185), when Heike family lost in a battle in 1183, they came to the area and built houses there. That means the housing technique has been inherited for more than 820 years. What is popular for this style is its function of wintertime when there is a lots of snow about 2 meters high. And also, material used are all organic wood and glass, also Washi (Japanese paper) is used for sliding doors.
It is easier to explain as a Frontier house, which has no particular designer, but villagers built it together as a community group. The first floor of the Gassho-style house must be constructed by carpenters, but the assembly of the roof structure can be built by the village people.
The grass for thatched roof is called Kaya (miscanthus). They grow it locally and crop in the autumn, and then start to thatch the roof. I thought that it is amazing to grow the material by their own. The old community system in rural area called “Yui” (tied), which villagers have close relationship for their general life such like helping each other with planting and cropping rice, but also re-roofing their house together. Not only the Gasho Zukuri style is historically important, however, the “Yui” system is also important to preserve as folk customs, since Japanese life has been more westernized and individualized.
The structure wooden frame is almost archival. Like old Japanese temples, they are assembled without nails, and also some parts are tied together with straw strings. Because people tend to set up a sunken hearth cut in the middle of the floor, burn ashes and coal to cook and warm up the house, the smoke tend to go up in the attic, which they use as a warehouse (like loft), so the rooms don’t be smoky, but makes the insects and mouse grow inside of the wooden frame killed. The smoke almost functions as spreading exterminator. Off course the wood frames became dark with the smoke, but it makes last longer. The roof grass on the other hand, need to change (re-roofing) in every 15 to 20 years, so in autumn, 100-200 people participating for re-roofing. (see photo)
The straw roof is cool in summer, and the steep shaped roof is easier to remove snow. People need to go up on the roof to clear the snow. It aesthetically looks nice to see that the houses in one area heading the same direction to avoid strong wind in winter, but welcome cool wind in summer. This way also keeps the house as strong as it is last longer. They are just an ancient people’s wisdoms than particular designer’s ideas.
It is said that “in 1935, Bruno Taut, German architect (1880-1938), visited Sirakawa village for exploring Toyama’s hosue in Mihoro, Toyama’s house was the biggest Gassho style house in Shirakawa village. Taut found that this Gassho style was very unique, and it was highly logical and rational little people architecture.” (The World Heritage Shrakawa-go site)