--- title: "Shirakawa-go's gasshō houses: why the thatched roofs are so steep" description: "The gasshō-zukuri farmhouses of Shirakawa-go have thatched roofs pitched at nearly 60 degrees. What the attic was for, how the roof is tied together, and how the village has kept its houses." url: https://kama-meshi.com/en/articles/shirakawa-go-gassho language: en published: 2026-11-11 category: "Places in Japan › Gifu" tags: ["Gifu", "WorldHeritage"] author: "Oginoya Editorial Team" publisher: "Oginoya Co., Ltd." translations: zh-TW: https://kama-meshi.com/zh-tw/articles/shirakawa-go-gassho ko: https://kama-meshi.com/ko/articles/shirakawa-go-gassho zh-CN: https://kama-meshi.com/zh-cn/articles/shirakawa-go-gassho zh-HK: https://kama-meshi.com/zh-hk/articles/shirakawa-go-gassho th: https://kama-meshi.com/th/articles/shirakawa-go-gassho de: https://kama-meshi.com/de/articles/shirakawa-go-gassho fr: https://kama-meshi.com/fr/articles/shirakawa-go-gassho es: https://kama-meshi.com/es/articles/shirakawa-go-gassho --- # Shirakawa-go's gasshō houses: why the thatched roofs are so steep ![A village seen from above: steep thatched farmhouses with their triangular gables all facing the same way stand among yellow rice fields, with dark cedar forest behind](https://kama-meshi.com/_astro/shirakawa-go-ogimachi-view-2009.DzWDlj2s_Z1UAKUr.webp) A gasshō-zukuri house is a large farmhouse of Shirakawa-go in Gifu Prefecture and Gokayama in Toyama Prefecture, with a thatched gable roof pitched at nearly 60 degrees. The roof is that steep to make room under it for an attic of two to four floors where silkworms were raised, and the whole house is built for a valley where snow lies two to three meters deep. ## Three villages on the Shō River Three villages of gasshō houses, all on the Shō River, were inscribed on the World Heritage List in 1995 as the Historic Villages of Shirakawa-go and Gokayama. Ogimachi is in the village of Shirakawa in Gifu, and Ainokura and Suganuma are in the city of Nanto in Toyama. Ogimachi is the largest of the three, with 128 households in 2023 and 59 gasshō houses in its preservation district, most of them built between the early nineteenth century and the early twentieth. The houses stand with their ridges running north to south, so from the hill at the north end of the village every triangular gable faces the same way. The two slopes of each roof face east and west, the sun falls evenly on both, and wet thatch dries easily. *Gasshō* means palms pressed together in prayer, and builders have long used the word for two timbers set against each other to form a peak. At their most numerous, at the end of the nineteenth century, there were about 1,850 gasshō houses, all in Shirakawa-go and Gokayama, among Japan's roughly 5.5 million farmhouses. ## A roof for silkworms Most thatched farmhouses in Japan have hipped or hip-and-gable roofs, and their attics, dark and airless, served at most for storage. A gasshō roof is a plain gable. Its frame is a row of paired logs joined at the top and spread apart at the bottom, and no posts stand inside it. The triangular walls at each end have windows fitted with paper screens, which let in light and air. The attic was divided into two to four floors, and there the household raised silkworms two or three times a year. Flat land in the valley was scarce. A separate silkworm shed would have taken a field that fed the family, and it would have been another roof to clear of snow. Under thatch the attic stayed cool in summer, and in early spring and autumn the heat of the hearth rose into it. ![The underside of a steep roof seen from inside: blackened round logs tied to each other with pale straw rope over a lining of reed screens, and a latticed window at the far end](https://kama-meshi.com/_astro/shirakawa-go-wada-house-roof-2008.CaC9JeH__Z5SC4r.webp "Roof timbers tied with straw rope in the attic of the Wada house, Ogimachi, April 2008.") Japan opened to foreign trade in 1859 and [raw silk became its largest export](https://kama-meshi.com/en/articles/tomioka-silk-mill), and silkworm raising grew quickly into the most important industry of Shirakawa-go and Gokayama. In the village of Shirakawa it ended in 1979. ## Carpenters below, neighbors above A gasshō house is built in two parts. The frame of posts and beams is carpenters' work, planed and jointed. The roof above the frame is the work of the villagers: logs left round and dressed with an axe, tied together with straw rope and with *neso*, lengths of witch hazel wood. Shirakawa is one of the snowiest places in Japan, with snowfall from December to March. The posts and beams of a gasshō house are thicker than those of an ordinary farmhouse, to carry the great roof and the snow on it. Some beams are cut from trees that the weight of snow bent at the root as they grew. ![A snow-covered village in a valley seen from a hill, its roofs and fields white, with a snow-laden branch and a fence rail in the foreground](https://kama-meshi.com/_astro/shirakawa-go-ogimachi-snow-2017.DR10zgWL_2nnvGT.webp "Ogimachi under snow, seen from the observation point on the site of Ogimachi Castle, February 2017.") ## Saltpeter under the floor Under the floor, households made *enshō*, saltpeter, the raw material of black gunpowder. A pit dug beneath the house was filled with soil, grass and silkworm droppings. Bacteria formed nitrates in the soil, the soil was leached with water, and the liquid was boiled down until crystals formed. Saltpeter was a military supply, controlled in Shirakawa-go by the shogunate's office at Takayama and in Gokayama by the Kaga domain. The pits needed a wide floor, and they are said to be a main reason the houses grew so large. In the Meiji era (1868–1912) cheap Chilean saltpeter was imported, official purchases stopped, and so did the work. In winter, above all in Gokayama, people also made [paper](https://kama-meshi.com/en/articles/washi). ## A roof thatched in a day *Yui* is an exchange of labor: a household that receives work repays it with the same amount of work. The largest jobs done by yui in Shirakawa were building a gasshō house and rethatching the roof. A roof is thatched in a single day, and as many as 200 people may come to help with a large house. Thatching is now also a trade, and local thatchers do many of the roofs, while roofs are still thatched by yui. ![A steep thatched farmhouse with metal scaffolding and dark sheeting along its side, a ladder leaning against the roof, paper-screened windows on two levels of its gable, and a tree in pink blossom to the left](https://kama-meshi.com/_astro/shirakawa-go-rethatching-2021.DA9827y1_1vHyTg.webp "A gasshō house in Shirakawa-go with its thatch being replaced, April 2021.") ## The Tōyama house at Miboro At Miboro, in the south of the village of Shirakawa, about 45 people lived together in the Tōyama house at its fullest, between 1897 and 1906. Only the heir lived in the house with a spouse, and the heir's brothers and sisters stayed in the houses where they were born even after they married. The large families are thought to have grown out of the need for hands in silkworm raising and the difficulty of setting up new households on so little land. The German architect Bruno Taut (1880–1938) spent May 17 and 18, 1935, studying the Tōyama house. In a lecture that year he said that in the rationality and logic of their structure the gasshō houses stood entirely alone in Japan. Taut found Japan's traditional beauty in Katsura Imperial Villa rather than in [Nikkō Tōshōgū](https://kama-meshi.com/en/articles/nikko-toshogu), and the wider fame of Shirakawa-go is said to date from what he wrote about its houses. ## Do not sell, do not rent, do not destroy The village of Shirakawa had about 300 gasshō houses in 1924, 191 in 1961 and 133 in 1970. Dams built on the Shō River between 1952 and 1958 submerged hamlets of gasshō houses. On December 25, 1971, the residents of Ogimachi formed an association to protect the village and adopted a charter with three rules for the gasshō houses and their natural surroundings: do not sell, do not rent, do not destroy. In 1976 Ogimachi was one of the first seven districts in Japan selected as Important Preservation Districts for Groups of Traditional Buildings. The Wada house, in the north of Ogimachi, is one of the largest gasshō houses in Shirakawa-go: 22.3 meters long and three stories high, and thought to date from the last decades of the Edo period (1603–1868). The Wada family were village headmen and checkpoint officials, and held a license to refine and sell saltpeter. The house was designated an Important Cultural Property in December 1995. ## References - [Shirakawa Village Office, "What is gasshō-zukuri?"](https://www.vill.shirakawa.lg.jp/1231.htm) - [World Heritage Center for the Historic Villages of Shirakawa-go and Gokayama, "Learning about gasshō-zukuri"](https://whc-shirakawa-goandgokayama.jp/learn/) - [World Heritage Center for the Historic Villages of Shirakawa-go and Gokayama, "Structure of gasshō-zukuri houses"](https://whc-shirakawa-goandgokayama.jp/learn/structure/) - [World Heritage Center for the Historic Villages of Shirakawa-go and Gokayama, "History and industry"](https://whc-shirakawa-goandgokayama.jp/background/) - [World Heritage Center for the Historic Villages of Shirakawa-go and Gokayama, "Preservation history and efforts in Shirakawa Village"](https://whc-shirakawa-goandgokayama.jp/to_shirakawa/attempt/) - [UNESCO World Heritage Centre, "Historic Villages of Shirakawa-go and Gokayama"](https://whc.unesco.org/en/list/734) - [Agency for Cultural Affairs, Cultural Heritage Online, "Wada Family Residence, main house"](https://online.bunka.go.jp/heritages/detail/188943) - [Kotobank, "Gasshō-zukuri"](https://kotobank.jp/word/%E5%90%88%E6%8E%8C%E9%80%A0-45247) Image credits (resized for display): - [663highland / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Ogi_Shirakawa-g%C5%8D,_Gifu,_Japan.jpg), [CC BY 2.5](https://creativecommons.org/licenses/by/2.5), 2009 - [Bernard Gagnon / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Gassho-zukuri_farmhouse-03.jpg), [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0), 2008 - [Suicasmo / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Shirakawa-go_20170202-3.jpg), [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0), 2017 - [Indiana jo / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Rethatcing_of_folk_house_in_Shirakawago.jpg), [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0), 2021