榛原郷の床と屋根 / 建築設計事務所SAI工房

土地の歴史を想起させる人工地盤と曲面屋根

敷地は、兵庫県丹波篠山市に位置する田園風景が広がる豊かな環境。大沢城跡をはじめ、周囲に遺跡が点在し、今なお同じ苗字の方々が住み続ける集落である。山間の谷間に位置し、眼前には水路が流れている。この地には、古代に湖が広がっていた伝承がある。それは不思議と納得のいく風景が広がっており、本計画では自然と戦い、寄り添いながら里山を形成してきた歴史を持つこの地に、新たな時を刻む建築の姿を想像した。

昔から湖の上に建っていたような人工地盤をもつ住まいをつくる。浮遊感のある土間スラブを覆うように、大きな軒下空間の中で内部と外部を一体的に設計した。夫婦と子供が新たな生活を営むために必要な水回りや個室を最小限にまとめ、人工地盤の上に少し振りながら配置した。残った余白をリビングや玄関、洗面スペースなど、それぞれに適したボリュームとして活用し、用途に適した天井高さを与える。リビングは開放的に、洗面スペースなどは最小限の高さとして計画した。この構成により南北に高さを抑えた勾配をもつ屋根と、それぞれを繋ぐことで生まれる東西に捻った屋根をもつ住まいが立ち現れたていった。平屋のようなプロポーションと捻った大きな屋根は、周囲の民家や山並みに呼応する。
大きな軒下空間を支える耐震壁を外周にバランスよく配置し、壁と壁の隙間には、周囲の豊かな環境を暮らしに取り入れることが出来る大きな開口部を設けた。光や風、水の音、四季、風土を感じながら周囲の風景が暮らしに溶け込み、彩りを与える。

数十年後の近未来では、建て替えを含めた新たな計画が生まれてくるはずである。その際、必ずこの人工地盤は、周囲の環境を含め、無視できない強いコンテクストとして、未来の設計者が歴史を踏まえ計画していくだろう。山々と田園風景、そして水路として存在するかつての湖と新たなこの建築の関係が時間を超え、はるか太古からそこに佇みながら応答してきた建築として、過去、未来の里山の姿を示していけるのではないか。（斉藤智士）

Artificial ground and curved roof that recalls the history of the land

The site is located in Tamba Sasayama City, Hyogo Prefecture, in a rich environment with a rural landscape. Ruins of Osawa Castle and other ruins are scattered in the surrounding area, and people with the same family name continue to live in the village. The site is located in a mountain valley with a waterway flowing in front of it. There is a legend about a lake in this area in ancient times. The landscape was strangely satisfying. In this project, we imagined an architecture that would mark a new time in this area, with a history of forming satoyama while fighting and cohabiting with nature.

We created a house with artificial ground as if it had been built on a lake for a long time. The interior and exterior were designed as one in an ample space under the eaves, covering a floating earthen floor slab. The water and private rooms necessary for the couple and their children to live a new life were kept to a minimum and placed on the artificial ground with a slight swing. The remaining blank space is used as a volume suitable for each living room, entrance, washroom space, etc., and is given a ceiling height suitable for each use. The living room was planned to be open, while the washroom and other spaces were planned to have a minimum size. This composition results in a house with a north-south sloping roof and an east-west twisting roof connected. The one-story proportions and the large, twisted roof echo the surrounding places and mountains.

The earthquake-resistant walls supporting the large space under the eaves are well balanced around the perimeter, and large openings are provided in the gaps between the walls to allow the richness of the surrounding environment to be incorporated into the living space. The light, wind, sound of water, the four seasons, and the climate of the surrounding landscape blend in and add color to one’s life. In addition, soon, several decades from now, a new plan, including reconstruction, will be created. At that time, this artificial ground will surely be a strong context that cannot be ignored, including the surrounding environment, and future designers will plan based on history. The relationship between the mountains, the countryside, and the lake that once existed as a waterway and the new architecture will transcend time, and as an architecture that has been there since time immemorial and has responded to the past, I believe that it will be able to show the past and future of the satoyama. (Satoshi Saito)