This addition to minka farmhouse and the teahouse are an elegant solution to the universal challenge of combining modernity and comfort with traditional vernacular architecture.
The owner’s father had built this minka in outskirts of Osaka eighty years ago. While it was one of several such houses in this area at that time, it is remarkable today that has survived the real estate speculation and rebuilding all ground it. However, with the exception of the structural framework and front exterior, all other parts of it have been drastically changed or remodeled over the years. Architect Kimura Hiroaki of Ks Architects sought to restore it to its original condition relying on the memory of the owner’s father and other surviving minka houses.
The style of the original building combines elements of minka farmhouses as well as elegant sukiya-style homes. This mixture is unusual in other parts of Japan but common in this area. It was probably developed because landowners here required the practicality of farmhouses for storage and work tools, but aspired to own sukiya homes like their counterparts in the city. During the restoration work, all previous additions and alterations that were not in the spirit of original building were stripped, and a new addition that neither competes with nor compromises the dignity of the old farmhouse was added.
This 176-square-meter house for a family of four and their pet dog now consists of the old minka, the new addition and the teahouse in the garden. The architect has used steel plates and gloss block as the predominant building materials for the new construction. His preference for using steel plate structures goes back fifteen years, inspired by the curved metal forms of trains and ships. Although earlier experiments with corrugated galvanized metal building were less than satisfactory, he soon realized the structural as well as aesthetic of 9-millimeter-thick steel sheets for smaller projects such as residences and churches. It was also a good coincidence that 9-millimeter steel was easy to get roll-pressed to exact shapes and dimensions.
While interior partitions of addition have been made of 9-millimeter steel sheets, this material has been combined with insulation and interior finishes to make up 100-millmeter-thick exterior walls. The impact of steel sheet is well articulated in the 8.5-meter-long walls of the corridor that separates the old and new construction. Steel angle ribs have been used here instead of traditional columns and are placed 960 millimeters apart, in the same rhythm as columns of the old minka. This method of construction is similar to that used for constructing living quarters of boats. While the architect usually specifies paint on steel surface, he chose to leave them unfinished in this project as they worked well with the rustic, un-hewn timbers of farmhouse.
In contrast to the addition to the minka, the free form of the metal teahouse makes it a sculptural presence in the garden. The semi-open exterior, the walls and roof are one continuous steel surface designed in response to the traditional garden that the owner’s father had tended for many years. It is also part of the architect’s long-term desire to create monocoque skin structures that are not dependent upon columns and beams. The plan of the teahouse, which is quite different from the other symmetrical buildings designed by him, is asymmetrical in order to accommodate the pine tree that stands in front of it. The structure was assembled in a factory, divided into two parts, transported to the site, and lowered into the garden by a crane. Its parts were then reconnected, fittings inserted, and interior furnishings—the alcove and two tatami mats—were added. Its size was influenced by the size of vehicles that transported it, while its forms lends it structural strength.
The exterior and interior of the teahouse have been given different aesthetic expressions. While the interior has traditional accoutrements such a tokonoma alcove and tatami mats, the exterior is finished with a smooth industrial heat-resistant paint similar to that used for automobiles. The sliding doors are made MDF. However, these modern materials and construction techniques come together to create a meditative quality similar to that found in traditional teahouse.