About the Arai Family Residence Main House
The Arai Family Residence Main House (新井家住宅主屋, Arai-ke Jūtaku Shuoku) is a late Edo-period farmhouse, built between 1830 and 1868, in Irumacho, Chofu City, Tokyo, and it was entered on Japan's register of Registered Tangible Cultural Properties on April 25, 2014.
It is a single-storey timber house standing in the middle of a plot ringed by old trees, with its front turned to the southeast. Of the five registered structures at the Arai Family Residence it shares the title of oldest with the inner storehouse, and the Meiji-era outer storehouse and silkworm rearing house were later set around its front yard.
Why the Main House Was Registered
The criterion is contribution to the historic landscape. The Agency for Cultural Affairs values the Arai main house as a farmhouse that still carries the quiet dignity of an old Musashino family seat. In other words, what was recognized is a late Edo farmhouse still lived in, in its original spot inside its woodland.
The roof is a Yosemune-zukuri hipped roof of Kayabuki thatch, now covered in sheet metal. The Agency's database records it as "thatch, with temporary sheet-metal covering". Officially, then, this is still a thatched house, and the metal is treated as a stopgap. Even under the metal, the big four-sided roof has the outline of a thatched Musashino farmhouse.
Inside the Arai Main House: The Floor Plan
The building area is 128 m². Facing the front, the right-hand side is a Doma, an earth-floored work space, and the rest is raised floor. The raised rooms sit in two rows: the hiroma and nakanoma in front, and the chanoma, heya and okunoma behind, five rooms in all.
So the back row is divided more finely than the front. The room names come from the Agency's description; how each room was used is not set out in the published sources.
A veranda runs along the southwest side of the Zashiki, the formal room. Behind the zashiki, a small room called the kuramae-zashiki leads straight into the inner storehouse, so the family could reach it without going outdoors. From the front of the Arai Family Residence Main House the middle gate and wall run west, separating the front yard from the main garden that the zashiki looks onto.
Seeing the Arai Family Residence Main House
The Arai Family Residence Main House is the heart of a private family home, and no interior opening has been announced (checked October 2026). It stands in the middle of the plot behind its trees, and how much of the roof can be seen from the street could not be confirmed. There is no official guidance on photography. Directions and contact details are on the Arai Family Residence page.
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Q&A
- When was the Arai Family Residence Main House built, and when was it registered?
- It dates from the late Edo period (1830 to 1868) and was registered as a Registered Tangible Cultural Property on April 25, 2014.
- Does the Arai Family Residence Main House still have a thatched roof?
- According to the Agency for Cultural Affairs, it is a hipped thatched roof now covered with temporary sheet metal.
- What is the floor plan of the Arai Family Residence Main House?
- An earth-floored doma on the right, then five raised rooms in two rows: hiroma and nakanoma in front, chanoma, heya and okunoma behind. A veranda runs along the southwest side of the zashiki.
- Is the Arai Family Residence Main House connected to the inner storehouse?
- Yes. Behind the zashiki, a small room called the kuramae-zashiki joins the house to the inner storehouse.
- Can I go inside the Arai Family Residence Main House?
- No interior opening has been announced (checked October 2026). It is a private home; the Chofu City Folk Museum is the place to ask.
Basic Information
| Name | Arai Family Residence Main House (新井家住宅主屋) |
|---|---|
| Location | 1-4 Irumacho, Chofu City, Tokyo |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | 2014 (registered) |
| Quantity | 1 building |
| Dimensions | Building area 128 m² |
| Owner | The Arai family (blank in the Agency for Cultural Affairs database) |
| Public Access | Not open (no visiting arrangements announced) |
References
- Database of National Cultural Properties (Agency for Cultural Affairs): Arai Family Residence Main House
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009923
- Cultural Heritage Online: Arai Family Residence Main House (Japanese)
- https://online.bunka.go.jp/heritages/detail/279810
- Database of National Cultural Properties (Agency for Cultural Affairs): Arai Family Residence Inner Storehouse
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009924
- Database of National Cultural Properties (Agency for Cultural Affairs): Arai Family Residence Middle Gate and Wall
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009927
- Chofu City: List of Designated and Registered Cultural Properties, PDF as of April 1, 2026 (Japanese)
- https://www.city.chofu.lg.jp/documents/2369/bunnkazai08.pdf
Last verified: 2026.10.01
