都心からほど近い埼玉県北本市は、荒川低地と中川低地に挟まれた大宮台地上に位置する。市街化調整区域に属する敷地周辺には、雑木林と畑の中に住宅が点在するのどかな農村風景が広がっている。屋敷林を抱えた農家の姿も残る一方で、農業の担い手不足や土地利用の変化により、農地は少しずつ宅地へと変わりつつある。しかし近年新たに建てられる住宅は、広い敷地を持ちながらも郊外住宅地に建つ住宅の佇まいとあまり変わらない。こうした状況を踏まえ、環境と建築の関係を再接続し、この場所に根ざした住宅のあり方を模索した。
敷地は、この地域の中でも最も標高が高く、西側には湧水によって侵食された谷津が広がり、起伏に富んだ里山景観が残る。この土地では古墳時代の竪穴式住居跡が発掘されており、水環境に恵まれた自然豊かな高台は、古代から人が住むのに適していたことがうかがえる。
隣地の傾斜林を下った先には、建主の両親が暮らす実家があり、この地域で生まれ育った夫婦は都心へ通勤しながら、世代を超えて住み継げる環境を求めて実家の建て替えを検討していた。そんな中すぐそばの高台の土地が売りに出された。こうした場所には、環境に素直に呼応する建ち方がふさわしいと感じた。
約1000m²の広い敷地で、建物を小さくまとめ南側に大きな庭を確保する一般的な配置とすると、庭が過度に開かれ、多くの近隣住宅と同様にカーテンを閉めたままの暮らしになり、豊かな自然との関係が希薄になってしまう。そこで、細長い平屋のヴォリュームに切妻屋根を架け、敷地に対し南西方向にわずかに振って配置することで、プライバシーを保ちながら四方向へ開放的な関係を築いた。建物の周囲には、眺望の広がる西側の庭、桜を植え近隣と共有できる東側の庭、家庭菜園を楽しむ南側の畑、雑木林に開かれた北側といった、性格の異なる外部空間が緩やかに分節され、それぞれとつながる住環境を目指した。
架構は、建物間口の半分にあたる1間半モジュールを基本とし、奥行きを調整しながら連続する単純な構成とした。その半分は、縁側を拡張したようなひとつながりの空間とし、南側の畑からダイニング、リビングを経て北側の雑木林へと視線が抜ける。長手方向には東西で対をなす外壁と開口の反復がリズムを生み、短辺方向にも抜けをつくる。
棟木下部に市松状に配した間仕切り壁により、小屋裏への奥行きを感じさせ、風景が見え隠れしながら多方向に展開することで、空間に広がりをもたらす。また内外で同一素材とした天井と壁により、内と外の境界は曖昧になり、深い軒先まで伸びる登り梁は意識を外へと導く。
屋根架構が連続する半屋外空間である外土間は、朝食をとったり、友人を招いて食事を楽しんだりと、暮らしが外へと広がるきっかけの場となり、ポリカーボネート仕上げのサンルームは、周辺環境との境界を緩やかにするバッファーゾーンとして機能する。大地に寄り添うように軒先を低く抑えたこの住宅は、地面に潜るように暮らした太古の住居のあり方をどこかに引き継ぎながら、道路側から見ると周辺に点在するビニールハウスのような佇まいで、風景にそっと馴染んでいる。
環境、敷地、建築の関係性に向き合いながら、性能や数値だけでは評価しきれない縁側や軒下、土間、サンルームといった半屋外的な要素に快適さを見出した。この場所ならではの風景を感じられる住まいのあり方が、日々の暮らしを豊かにし、家族はこの地に根ざしていく。
（滝沢茂雄）
Located within easy reach of central Tokyo, Kitamoto City in Saitama Prefecture sits on the Omiya Plateau, between the Arakawa and Nakagawa lowlands. The site lies within an urbanization control area, where houses are scattered among fields and mixed woods, forming a peaceful rural landscape. Farmhouses surrounded by groves of trees still remain, while a shortage of agricultural workers and changes in land use are gradually transforming farmland into residential plots. Yet despite occupying spacious sites, many newly built houses differ little in appearance from those found in suburban housing developments. In response to these conditions, the project sought to reconnect architecture with its environment and explore a form of housing rooted in this place.
The site is located at the highest points in the area. To the west lies a valley eroded by spring water, where an undulating satoyama landscape remains. The remains of pit dwellings dating from the Kofun period have been excavated on the site, suggesting that this elevated land, with abundant water and a rich natural environment, has been a suitable place for human habitation since ancient times.
At the bottom of the wooded slope on the neighboring property stands the family home where the clientʼs parents live. The couple, both of whom were born and raised in the area, commute to central Tokyo and had been considering rebuilding the family home as a place their family could continue to inhabit for generations. During this time, a nearby plot on higher ground came up for sale. The site seemed to call for a building that would respond directly and naturally to its surroundings.
On a large site of approximately 1,000 square meters, a conventional arrangement—concentrating the house into a compact volume and leaving a large garden to the south—would have made the garden overly exposed. As in many neighboring houses, the curtains might then have remained constantly drawn, weakening the relationship with the rich natural surroundings. We therefore placed a long, narrow, single-story volume topped with a gabled roof, rotating it slightly toward the southwest relative to the site. This arrangement creates open connections in all four directions while maintaining privacy. Around the house, outdoor spaces with distinct characters are loosely defined: a western garden with expansive views, an eastern garden planted with a cherry tree and open to the neighborhood, a southern vegetable garden, and a northern area open to the mixed woods. The aim was to create a living environment connected to each of these different outdoor spaces.
The structural frame is based on a 2.730-meter (1.5-ken ) module, equivalent to half the width of the building, repeated in a simple sequence while the depth is adjusted. One half of this gabled cross-section forms a continuous space like an expanded engawa, with a sightline from the vegetable garden to the south, through the dining and living spaces, and toward the mixed woods to the north. Along the length of the house, the repetition of corresponding exterior walls and openings on the east and west sides creates a rhythm, while sightlines also extend across the shorter axis.
Partition panels arranged in a checkerboard pattern beneath the ridge beam create a sense of depth leading into the roof space. As shifting views of the landscape unfold in multiple directions, the interior gains a greater sense of expansiveness. The ceilings and walls are finished in the same materials inside and out, further blurring the boundary between interior and exterior. The sloping roof beams extending toward the deep eaves draw the eye outward.
The exterior doma is a semi-outdoor space beneath the continuous roof structure, providing a setting where daily life can extend outside, whether for breakfast or for meals with visiting friends. The polycarbonate-clad sunroom functions as a buffer zone that softens the boundary between the house and its surroundings. With its eaves kept low, as though nestling against the earth, the house carries forward something of the character of ancient dwellings in which people lived partly below ground, while, seen from the road, it resembles the plastic greenhouses scattered throughout the surrounding area, allowing it to blend quietly into the landscape.
The exploration of the relationships among the environment, the site, and the architecture revealed a sense of comfort in semi-outdoor elements such as the engawa, the space beneath the eaves, the doma, and the sunroom̶one that cannot be fully evaluated through performance data or numerical value alone. This form of housing, which allows the family to experience the landscape unique to this place, enriches their everyday life and enables them to put down roots here.
(Shigeo Takizawa)
【北本の住宅】
所在地：埼玉県北本市
用途：戸建住宅
クライアント：個人
竣工：2024年
設計：滝沢茂雄建築設計事務所
担当：滝沢茂雄
構造：多田脩二構造設計事務所
施工：蓮見工務店
撮影：吉田 誠
工事種別：新築
構造：木造
規模：平屋
敷地面積：974.70m²
建築面積：143.38m²
延床面積：129.18m²
設計期間：2021.06-2023.04
施工期間：2023.05-2024.02
【House in Kitamoto】
Location: Kitamoto-shi, Saitama, Japan
Principal use: Residence
Client: Individual
Completion: 2024
Architects: Shigeo Takizawa Architects
Design team: Shigeo Takizawa
Structure engineer: Shuji Tada Structural Consultant
Construction: Hasumi Komuten
Photographs: Makoto Yoshida
Construction type: New building
Main structure: Wood
Building scale: 1 story
Site area: 974.70m²
Building area: 143.38m²m²
Total floor area: 129.18m²
Design term: 2021.06-2023.04
Construction term: 2023.05-2024.02
