Nishiyama Family Residence Main House

What Is the Nishiyama Family Residence Main House?

The Nishiyama Family Residence Main House (西山家住宅主屋, Nishiyama-ke Jūtaku Shuoku) is a wooden house of 1912 at the north end of the Nishiyama Family Residence in Okamachiminami, Toyonaka City, Osaka Prefecture, registered as a Registered Tangible Cultural Property of Japan in 2018.

It is a timber building, single-storey with a partial second floor, under a tiled roof, with a building area of 175 square meters. The house faces north. A single-storey wing runs east to west, and a two-storey wing runs north to south from its western end, so the plan forms an L. Its registration number is 27-0755.

Everything else on the site came later. The main house began as the ready-built house that the Nishiyama family bought, together with its lot, in October 1912.

Why the Main House Was Registered

The Nishiyama Family Residence Main House was added to the register on November 2, 2018, under the criterion for buildings that serve as a model of design. It became a Registered Tangible Cultural Property in the second round of listings at the site, eleven years after the garden buildings.

The Agency for Cultural Affairs points to the floor plan. The low east-west wing was for receiving guests; the two-storey north-south wing was where the family lived. The two routes through the house, one for visitors and one for daily life, were kept clearly apart, and the reception side even had a small tea room in the sukiya manner. The agency reads this as a typical arrangement of the modern suburban house.

Put simply, a modest commuter's house on a railway estate was gradually turned, over about thirty years, into a home that could entertain guests properly. The main house shows both stages at once.

What to Look For at the Main House

The original house inside the later one

The 1912 sales contract describes a two-storey tiled house with a footprint of 25.5 tsubo (about 84 square meters), of which only 7.5 tsubo was upstairs. That is less than half the present Nishiyama Family Residence Main House, and it was only the north-south wing. The east-west wing was added later.

According to Toyonaka City's preservation plan, the only parts that keep their original form are an 8-mat tatami room on the ground floor of the north-south wing and part of the upstairs veranda. The rest records a long series of changes: a kitchen extension in 1913, an upstairs sunroom around 1935, a new entrance and kitchen by the Mitsukoshi department store's housing division in 1941 and 1942, and a rebuilt bathroom area between 1968 and 1970. Reading those layers is the real pleasure of this building.

Two roofs, two characters

The roofs tell the wings apart. The upper floor has a gabled roof of ordinary interlocking tiles with a lean-to roof beside it. The reception wing below has a hip-and-gable roof finished with ichimonji tiles, whose lower edges are cut perfectly straight so that the eave reads as one clean line. The side guests saw got the finer roof.

The inner garden from the veranda

From the south veranda of the Nishiyama Family Residence Main House you look onto a small inner garden designed by Mirei Shigemori in 1940. Three stepping-off stones are linked by long rectangular slabs and stepping stones, with white Shirakawa sand in the joints. It is a crisp, modern design built on straight lines, separated from the larger Seiryūtei garden to the south by a stone wall and an osmanthus hedge. The veranda itself was rebuilt in 1941 to suit the new garden.

Visiting the Main House

The Nishiyama Family Residence Main House stands inside the high walls and is not open on a regular basis. Through 2026 it has been under repair together with the high wall, and Toyonaka City ran a tour of the repair work on July 4, 2026. For now, the only chance to see it up close is to join one of the city's events or tours (checked October 2, 2026).

If you get in, start at the front door at the end of the stone path from the north gate, then go round to the south veranda and look back across the inner garden to see how the two wings and their roofs fit together. Photography rules are announced for each event, so check when you register. Directions and how to apply for events are on the Nishiyama Family Residence page.