SITE HISTORY
Osaka Sakai, where the site is located, is a core city in the historic South Osaka area. Historically, the tombs of the emperor and powerful people have been built, but now they have begun to wonder if they could make a tomb within the premises of their house.
The present housing design faces "life" but not "death", which means in case of housing, rooms are planned based on functions, usually based on lively activities of residents, and it is difficult to plan blank spaces that do not want specific function.
As a result of investigation, it turned out that creating the cemetery in the residential area is legally prohibited at present. The location after death in modern times has been functionally determined by zoning as a graveyard. Normally, the typical place in the house facing the dead is the altar, however the architect thought that he would like to create a house that is unconventional, containing a space that feels dark, and symbolizing death.
ARCHITECTURAL PLAN
The daily space on the south where three family members live, and the non-everyday space on the north side are planned. The daily space has a double-skinned structure below the gable roof, with an earthen corridor and rim around it, with a living room on the first floor and two rooms on the second floor. The buffer space between the ground floor and the rim is a coordination space that creates a gentle relationship with the outside. Four layers of bookshelves are provided in the space between the structure wall and the sliding door facing the buffer space, and an open space without the structure wall. The bookshelf and the ground floor responded to the residents’ request as they wanted to create a library-like place where local children and other nearby residents could stop in the future. The outer walls are made of baked cedar and the interior space is finished with a wooden structure.
This house has an egg-like form, with a blowout space of 6.4m in height. The stairs connect the first and second floors, but the architect thought to create an empty space, that is, an "intermediate" space in everyday life. It also has two small dome spaces inside, a bathroom and a laundry room. In addition, the Otani stone fence of the dismantled existing house is reused as paving stones and the original existing gardens are left behind as they were.
ENVIRONMENTAL PLAN
In summer, the fixtures can be adjusted in the north dome space and the south living space to create an indoor wind environment while restricting direct light to enter the living room on the first floor.
In winter, the living room space on first floor takes in direct light, stores heat by the soil between the floors, and closes the sliding door to create an indoor environment that is not easily affected by the external environment. The rooms on the second floor also form a podium-like environment that is not easily affected by the external environment by closing the shoji sliding door and the movable ceiling.
STRUCTURAL PLANNING
At first, bamboo was layered spherically, in which split bamboo were woven like a fence and a dome was made of soil. It had to be made of wood, but it was difficult to use something like curved laminated timber because of its high cost. As a result of trial and error on how to make a spherical surface with a straight wooden member, making a large bow-shaped “framework” by putting two pieces of short-cut wood together while shifting the cut and sandwiching it with a plywood board and fastening with screws was the adopted method. Then they were arranged radially to form the entire framework, a plywood board was attached, and a soil wall was used to form a strong cubic structure with only straight and flat members.