The Structure and Techniques of Gassho-Style Houses
One particularly unique architectural feature of Gassho-style houses is that the truss structure (the frame supporting the roof) and the shaft structure (the first floor) are clearly separate, unlike typical houses. While the shafts are built by specialized carpenters using traditional techniques, the trusses are built by the people of the village, working together. Although the roof trusses are a bit rough in design, they feature touches throughout to better suit them to the local climate.
The truss structure that makes up the roof has an equilateral triangle cross-section. The 60° angle of the top ridge is considered to be more resilient against weight and pressure from above or the sides, so these roofs can withstand wet, heavy snow and strong seasonal winds. The logs used to build these roofs are tied together with ropes or vines - no nails are used in their construction.The triangular truss structure is simply inserted on top of the shaft structure. It is not fixed into place, giving it the flexibility to handle the heavy snows.The thick beams with curved ends are called chonnabari, and they play a key role in having the pillars support the weight of the roof. These beams are made from bent trees that grow on the slope of the mountain, to help distribute the considerable weight of the roof onto the pillars, for a more structurally resilient and visually appealing design.
Use of the Entire Space
The entirety of the space in these houses was put to practical use: the large attic space under the roof was used for raising silkworms, while the dirt-floored area was used for washi paper production. In addition, saltpeter would be prepared below the floorboards.
Below the Floorboards: Used for making saltpeter.Large Attic: Used for raising silkworms.Large Paper Windows Draw In Light for Raising SilkwormsDirt-Floored Area: Used for making washi paper.
Below the floorboards, around the irori sunken hearth, people would dig holes 2.7 meters deep, and fill them with soil, mugwort and other mountain plants, and silkworm waste. Over the following four years, this mixture would decay and undergo further processes, eventually becoming saltpeter. Saltpeter was then used as the main ingredient for gunpowder for rifles. Indeed, gunpowder production was once one of the major industries of Gokayama.
The Ancient Design Remains Well Preserved "The Murakami Family Residence"
The Murakami Residence is located in the Kaminashi district of Nanto. It has undergone few renovations, making it a valuable Gassho-style house that largely retains its original appearance from 350 years ago. On display at the house, there are materials relating to the traditional industries of Gokayama during the Edo Period (1603–1868 CE): making saltpeter and washi paper.
The Oldest Form of Gassho-Style House "The Haba Family Residence"
The Haba Residence is located in the Tamukai area, opposite Kaminashi in Nanto. It is believed to have been built around the mid 18th century. This is the oldest style of Gassho-style house, and elements unique to the period can be seen in the layout of the rooms, the size, and the way the materials are finished.
One of the Largest Gassho-Style Houses in Japan "The Iwase Family Residence"
The Iwase Residence is located in the Nishi-Akao district. It was built in the mid 18th century over a period of eight years. This five-story building is 14.4 meters tall, making it among the largest Gassho-style houses of its kind in Japan. Because the residence served as housing for the Kaga Domain government official with the important role of delivering saltpeter to the Domain government, it was specially authorized to use Japanese zelkova wood in its construction. It is made entirely of thick, high-quality Japanese zelkova lumber, and is considered the pinnacle of Gassho-style architecture.
The History and Culture of Gokayama, through Folk Songs
Many folk songs have long been sung in Gokayama. The best known of these are "Kokiriko" and "Mugiyabushi."
"Kokiriko" is said to be the oldest folk song in Japan, and that it originated from the songs and dances performed for the gods of the rice fields as a prayer for a good harvest. In Gokayama, this tradition remains unbroken: even today, people perform it with a unique bamboo instrument called the kokiriko, for which the song is named, and dance wearing old-fashioned attire.
"Mugiyabushi" is believed to date back to the late 12th century, when a soldier of the Taira clan fled to Gokayama after defeat in battle. It was here that he hung up his sword and took up the hoe and sickle, and he would sing a song as he harvested barley. Today, the men of the village hold conical straw hats and strike poses as they dance to the song’s melancholy tune, telling the tale of Gokayama's prosperous history.
