Five Sawtooth Roofs on Walls of Ōya Stone
The Former Soga Textile Factory (旧曽我織物工場, Kyū-Soga Orimono Kōjō) is a single-storey weaving shed of timber-framed stone construction built in 1922 in Honchō 1-chōme, Kiryu City, Gunma Prefecture, entered on the national register of Registered Tangible Cultural Properties on 2 March 2006.
The Agency for Cultural Affairs also lists it under the name Sakei Sangyō Honchō Factory. It stands at the very back of the long Soga family plot, beyond a parking area on the west, and covers 550 square metres, several times the footprint of any building at the front of the property.
The roof is a sawtooth (Sawtooth roof). Its steep north-facing slopes are glazed, letting in steady light without direct sun, which is what weavers needed to judge colour and catch flaws in the cloth. The Former Soga Textile Factory carries five of these ridges and, unusually, walls of stone.
Fifty Years of the "New Mill"
The Former Soga Textile Factory was built when the family's second head, Kiichirō, married, and at the time it was simply called the new mill. It marks the point at which a household that had made its money dealing in raw silk began weaving cloth itself.
The industry peaked in Kiryu in the late 1930s. Then, under the wartime industrial control order of 1943, every loom in the building was requisitioned.
After the war the shed restarted with two looms borrowed from Kiryu Technical High School. By 1951 it held 26 and still could not keep up with orders, sending work out to subcontractors. Weaving stopped around 1970, and the building then served other local firms as a factory and warehouse. Kiryu City says active reuse of the building is under consideration.
Timber Frame, Stone Walls
The Former Soga Textile Factory is built in the method known as mokkotsu sekizō: the posts and roof structure are timber, and the outer walls are Ōya stone, a light, easily worked volcanic tuff quarried in neighbouring Tochigi Prefecture, cut into blocks and laid in level courses.
According to the Agency for Cultural Affairs, the building runs eight bays along its length and is spanned by five sawtooth bays of 20 shaku each (about 6 metres). The ridges run east to west, so the glazing faces north.
Kiryu City supplies finer figures: 21.58 metres east to west and 30.65 metres north to south, with each bay measuring 6.07 by 5.46 metres. At each bay division and at the free-standing posts along the length, the outer wall is stiffened by a pier 40 centimetres wide and about 10 centimetres deep. Each ridge carries four round ventilation towers, and inside, posts 14.5 centimetres square support trusses whose beams and diagonals are tied with steel rods.
Doors and windows are spanned by lintels and fitted with double iron doors. The west gable is built in stone right to its peak and pierced by a round vent. Later work replaced the roof covering with sheet metal and the window frames with aluminium sash.
Visiting the Former Soga Textile Factory
The Former Soga Textile Factory is privately owned and the interior is not open; only the exterior can be seen. Because it stands at the back of the Soga plot, it cannot be seen directly from Honchō-dōri, and the grounds cannot be entered, so any view is from outside the property.
The stonework is what to look for: level courses of cut Ōya stone, with the stiffening piers standing proud of the wall like pilasters at each bay. The round vent in the west gable and the circular ventilation towers on the roof are details that mark out this building. Kiryu City asks for permission to be obtained before photographing buildings in the preservation district.
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Q&A
- Can you go inside the Former Soga Textile Factory in Kiryu?
- No. The building is private and the interior is closed; only the exterior can be seen. Kiryu City says reuse is under consideration, but there is no public access at present. Please do not enter the grounds.
- What are the walls of the Former Soga Textile Factory made of?
- Ōya stone, a volcanic tuff from Tochigi Prefecture, cut into blocks and laid in level courses around a timber frame.
- How is the Former Soga Textile Factory related to the Soga Family Residence?
- They share one plot. The factory stands at the back and was built in 1922 when the second head of the family, Kiichirō, married. The main house, storehouse, reception wing, Inari shrine and gate at the front are separately registered.
- Why does the Former Soga Textile Factory have a sawtooth roof?
- The glazed faces of a sawtooth roof point north and admit steady light without direct sun, ideal for judging colour and weave. Here there are five sawtooth bays of about 6 metres each, with ridges running east to west.
- When did the Former Soga Textile Factory stop weaving?
- Around 1970. All its looms were requisitioned under the 1943 wartime controls; production restarted with two borrowed looms after the war and reached 26 by 1951. The building was later used as a factory and warehouse by other local companies.
Basic Information
| Name | Former Soga Textile Factory (旧曽我織物工場) |
|---|---|
| Location | Ko 225-1, Honcho 1-chome, Kiryu City, Gunma Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered on 2 March 2006 |
| Quantity | 1 building |
| Dimensions | Timber-framed stone construction, single storey, sheet-metal roof; building area 550 m². Five sawtooth bays of about 6 m |
| Owner | Private (owner not listed in the Agency for Cultural Affairs database) |
| Public Access | Not open to the public (exterior viewing only) |
References
- National Cultural Properties Database (Agency for Cultural Affairs): Former Soga Textile Factory
- https://kunishitei.bunka.go.jp/heritage/detail/101/00005248
- Cultural Heritage Online: Former Soga Textile Factory
- https://online.bunka.go.jp/heritages/detail/181466
- Kiryu City: Former Soga Textile Factory (in Japanese)
- https://www.city.kiryu.lg.jp/kankou/bunkazai/1010700/kunitouroku/1002006.html
- Kiryu City: Former Soga Textile Factory, commentary PDF (in Japanese)
- https://www.city.kiryu.lg.jp/_res/projects/default_project/_page_/001/002/005/soga_koujou.pdf
- Kiryu City: Outline of the Kiryu Shinmachi Preservation District (in Japanese)
- https://www.city.kiryu.lg.jp/kankou/spot/denken/about/1003081.html
Last verified: 2026.09.24
