A Sealed Room for Disinfecting Silkworm Tools
The Sato Family Residence (Mitsubiki) Disinfection Room is a two-story earthen-walled building put up in the late Meiji era on the estate of a silkworm-egg producer in Kamishiojiri, Ueda, Nagano Prefecture, and it was registered as a Registered Tangible Cultural Property on June 24, 2021. In Japanese it is 佐藤家住宅（三ツ引）消毒室, Satō-ke Jūtaku (Mitsubiki) Shōdokushitsu. Its ground floor is a sealed chamber for disinfection; its upper floor was a rearing room for silkworms.
It stands south of the main house with its ridge running north to south, under a gabled tile roof entered from the long side, in the Hirairi manner. A single raised ventilation roof, a koshi-yane, sits at the middle of the ridge. The building covers 23 square meters and is dated to late Meiji, sometime between 1898 and 1912.
Ueda City explains that most of the estate was extended or remodeled as the egg trade grew through late Edo and Meiji, and that the compound was pictured in a book of copperplate views published in 1897. The Disinfection Room came later. With it, the estate's rooms for rearing silkworms reached nine.
Why It Was Registered
The registration criterion is contribution to the historic landscape of the country. The Agency for Cultural Affairs presents the Sato Family Residence (Mitsubiki) Disinfection Room as a remnant that shows what the silkworm-egg business actually involved. Of the nine registered structures on the estate, it is the only one named for a step in the work.
For a family whose product was eggs, keeping disease out of the rearing rooms mattered more than almost anything. Ueda City describes this building as a room plastered on the inside so that the tools of silkworm rearing could be disinfected there. Giving that job its own sealed space, apart from the house and the storehouses, shows how carefully the trade had organized its routines by the end of the Meiji era.
The stacking of tasks is worth noticing. Tools were cleaned downstairs and silkworms were raised upstairs. Read together with the rearing rooms in the Silkworm Room and above the Storage Shed, it shows the whole southern half of the estate working as a single production floor.
What to Look For
The outer walls are plastered with clay right up under the eaves and left at the middle coat, a matte earthen skin rather than bright white, the same finish used on the estate's other earthen storehouses.
Inside, the ground floor is one room whose walls and ceiling were packed with clay to seal it and then finished in Shikkui lime plaster. Plastering the ceiling as well as the walls closed the room off completely. Upstairs is a single wood-floored room that served for rearing, and the koshi-yane on the ridge was most likely there to ventilate it, drawing off heat and damp.
The Agency for Cultural Affairs database has a photograph of the east side of the Sato Family Residence (Mitsubiki) Disinfection Room. Heavy clay walls topped by a small ventilation roof make it clear, even from outside, that this was not an ordinary storehouse for goods.
Visiting the Disinfection Room
The Sato Family Residence (Mitsubiki) Disinfection Room stands inside a private estate, just south of the main house, and is not open to the public. We could not confirm how much of it can be seen from outside the property, and we found no published guidance on photography.
The database photograph is the surest way to see the building. Directions to the estate and the story of the whole compound are on the Sato Family Residence (Mitsubiki) page.
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Q&A
- Can you visit the Sato Family Residence (Mitsubiki) Disinfection Room?
- No. It stands inside a private estate and is not open to the public, and there is no published guidance on visits or photography. A photograph of the exterior is available in the Agency for Cultural Affairs database.
- What was the Sato Family Residence (Mitsubiki) Disinfection Room used for?
- The ground floor was a room for disinfecting silkworm-rearing tools, with walls and ceiling packed with clay to seal it and finished in lime plaster. The upper floor was a single wood-floored room used for raising silkworms.
- When was the Sato Family Residence (Mitsubiki) Disinfection Room built?
- It dates from late Meiji, between 1898 and 1912, and was built after the estate appeared in a book of copperplate views published in 1897. It was registered as a Registered Tangible Cultural Property on June 24, 2021.
- How big is the Sato Family Residence (Mitsubiki) Disinfection Room?
- It is a two-story earthen-walled building covering 23 square meters, with a gabled tile roof entered from the long side and a single raised ventilation roof at the middle of the ridge.
- What is the small roof on top of the Sato Family Residence (Mitsubiki) Disinfection Room?
- It is a koshi-yane, a raised ventilation roof with openings high up that let air through. It most likely served to carry heat and damp out of the rearing room on the upper floor.
Basic Information
| Name | Sato Family Residence (Mitsubiki) Disinfection Room |
|---|---|
| Location | 90 Minamigawa, Kamishiojiri, Ueda City, Nagano Prefecture |
| Designation | Registered Tangible Cultural Property (Building) |
| Year Designated | Registered 2021/6/24 (Reiwa 3) |
| Quantity | 1 building |
| Dimensions | Earthen storehouse construction, 2 stories, tiled roof, building area 23 square meters |
| Owner | Private owner (name not published) |
| Public Access | Not open to the public (private estate) |
References
- Database of National Cultural Properties (Agency for Cultural Affairs): Sato Family Residence (Mitsubiki) Disinfection Room
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00013791
- Cultural Properties of Ueda City (Ueda Citizens' ICT Promotion Center): Sato Family Residence (Mitsubiki)
- https://museum.umic.jp/bunkazai/document2/127.php
Last verified: 2026.09.26
