An Experimental House on the Southern Slope of Mount Tsukuba
The Former Yanaka Family Residence (旧矢中家住宅) in Hojo, Tsukuba City, Ibaraki Prefecture, is a modern Japanese-style house of the Showa era whose 2 surviving buildings, a main house of 1942 and an annex completed in 1949, were designated an Important Cultural Property in 2023.
It was built by Yanaka Ryujiro, a materials researcher and businessman born in Hojo. He developed the cement waterproofing compound sold as Manol and founded the firm that manufactured it. In 1955 he received the Medal with Purple Ribbon for his contributions.
Construction began in 1938 and continued until 1953, a campaign of 15 years. The grounds run to roughly 770 tsubo, about 2,500 square meters, and the main house and the annex are set at different levels on sloping land with a garden filling the space between them. Yanaka died in the house in 1965.
His family left soon afterwards, and the property stood close to empty for some 40 years. Ownership passed out of the Yanaka family in 2008, and a conservation effort began with nothing more ambitious than cleaning. The site is now run by a non-profit organisation, the Guardians of Yanaka no Mori.
Why It Was Designated
Two grounds were cited: academic value and quality of design.
The academic case rests on the fact that Yanaka used his own home as a test bed. Part of the main house is roofed flat, unusual for a timber building, and the waterproofing compound he had invented was applied there. The rendered walls carry pigments he mined and refined himself. He was, in effect, checking on his own roof whether a wooden house could carry a flat deck in the Japanese climate.
Ventilation runs through both buildings as a shared concern. Air vents were cut at many points in the walls, and the fittings themselves were designed with airflow in mind. The citation treats the house as an attempt to answer, from the materials side, the problem of making timber construction last in a hot and humid country.
On the design side, the citation points to painted cedar doors, painted sliding screens and ink paintings by Nanbu Harukuni distributed through the rooms, and to the selection of prized cherry, zelkova and cedar timbers. The main house covers 197.53 square meters, is of timber construction with a basement, and has stone steps on the south and west and a covered passage on the north. The annex covers 90.31 square meters over 2 storeys, reinforced concrete below and timber above.
The designation reaches past the buildings. The sloping site itself, together with the stone walls and retaining walls that define it, is covered by the protection, and 1 stone storehouse is included as an attached designation.
What to Look at
The annex was built to receive guests of the highest rank, and it shows. Painted board doors line the corridor, ceilings are set high, and furniture made to order for the rooms is still in place. The switch from reinforced concrete on the ground floor to timber above is not obvious from outside.
In the main house, compare the fittings room by room. They were not standardised, and each space handles its openings differently. Once you start looking for the ventilation openings around walls and transoms you will find a surprising number of them. The basement is built of Oya stone, the soft volcanic tuff quarried north of here in Tochigi.
The colour of the exterior is worth a moment as well. The deep yellow render is a direct demonstration of the pigments Yanaka worked with.
Much of the original furniture and fixed equipment survives at the Former Yanaka Family Residence. That so little was lost during 40 years of near-abandonment is what allows the house to be read now as a record of Showa domestic life rather than a shell.
Visiting the Former Yanaka Family Residence
The Former Yanaka Family Residence opens to visitors under the name Yanaka no Mori. Opening is normally every Saturday, from 11 a.m. to 4 p.m. There are 2 guided tours a day, at 11 a.m. and 2 p.m., with limited places. Tours are sometimes suspended, and in some months an opening week is dropped altogether, so check the organisation's own site before travelling.
A contribution of 500 yen per person towards maintenance and repair is requested; junior high school students and younger visit free. To protect the floors, visitors are asked to wear socks.
By public transport, take a bus toward Mount Tsukuba from the Tsukuba Center terminal beside Tsukuba Station on the Tsukuba Express, and get off at Hojo; the house is within walking distance from there. Drivers should use the free shared car park for the Hojo shopping street, then follow Prefectural Route 138 east for about 400 meters to the entrance. Notices ask visitors not to park on private or shop premises.
No formal policy on photography has been published. Asking your guide during the tour is the reliable route. Opening days, hours and the contribution figure were checked against the Guardians of Yanaka no Mori in September 2026.
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Q&A
- Can I visit the Former Yanaka Family Residence, and what does it cost?
- Yes. It opens as Yanaka no Mori, normally every Saturday from 11 a.m. to 4 p.m. A maintenance contribution of 500 yen per person is requested, free for junior high school students and younger. Some weeks are dropped, so check the official site before you go.
- When are the guided tours at the Former Yanaka Family Residence?
- There are 2 each opening day, at 11 a.m. and 2 p.m., with a cap on numbers. They are occasionally suspended. Visitors are asked to wear socks inside to protect the building.
- When was the Former Yanaka Family Residence designated an Important Cultural Property?
- On 25 September 2023. The designation covers the main house of 1942 and the annex completed in 1949, with 1 stone storehouse as an attached designation. The grounds, stone walls and retaining walls are protected along with the buildings.
- Who was Yanaka Ryujiro, who built the Former Yanaka Family Residence?
- A building-materials researcher and businessman from Hojo. He developed the cement waterproofing compound Manol and founded the company that made it, and in 1955 he was awarded the Medal with Purple Ribbon. His own house doubled as a place to test his results.
- How do I get to the Former Yanaka Family Residence, and is there parking?
- Take a bus toward Mount Tsukuba from Tsukuba Center and alight at Hojo, then walk. Drivers can use the free shared car park for the Hojo shopping street and follow Prefectural Route 138 east for about 400 meters. Please do not park on private or shop premises.
Basic Information
| Name | Former Yanaka Family Residence |
|---|---|
| Location | 94-1 Aza-Kojo, Hojo, Tsukuba City, Ibaraki Prefecture |
| Designation | Important Cultural Property |
| Year Designated | 2023 (Reiwa 5) |
| Quantity | 2 buildings (main house and annex), with 1 stone storehouse as an attached designation |
| Dimensions | Main house, building area 197.53 square meters; annex, building area 90.31 square meters |
| Owner | Private owner |
| Public Access | Opened by the non-profit Guardians of Yanaka no Mori, normally every Saturday from 11 a.m. to 4 p.m. 2 guided tours daily, at 11 a.m. and 2 p.m. Maintenance contribution of 500 yen per person, free for junior high school students and younger |
References
- Agency for Cultural Affairs, National Designated Cultural Property Database: Former Yanaka Family Residence, Main House
- https://kunishitei.bunka.go.jp/bsys/maindetails/102/00005486
- Agency for Cultural Affairs, National Designated Cultural Property Database: Former Yanaka Family Residence, Annex
- https://kunishitei.bunka.go.jp/bsys/maindetails/102/00005487
- Yanaka no Mori: About the Former Yanaka Residence
- https://www.yanakanomori.org/?page_id=156
- Yanaka no Mori: Guide to House Openings
- https://www.yanakanomori.org/?p=9973
- Tsukuba City: Tsukubus Community Bus Guide
- https://www.city.tsukuba.lg.jp/soshikikarasagasu/toshikeikakubusogokotsuseisakuka/gyomuannai/2/1/1001471.html
Last verified: 2026.09.06
Cultural Treasures in the Same Area
All are within walking distance in the same area, so we recommend visiting them together.
- Former Yanaka Family Residence Main Building 0.00 km
- Former Yanaka Family Residence Annex 0.03 km