PROJECT

PROJECT2023.09.25

ダイカンヤマの家 / アキチアーキテクツ

住宅密集地に抜ける光と風を最大限享受する住まい

敷地は都心の住宅密集地で、30年ほど前に同時分譲された住戸群が世代交代に伴い、移転や建て替えが始まったエリアである。前面道路は2項道路、裏側は落差4m弱の崖地であり、間口5.4m、東西方向に奥行き16m弱のうなぎの寝床状の敷地に対するさまざまな制約の隙間を縫いながらも、伸びやかな住宅を目指した。
道路のセットバックと崖からの離隔距離を確保した間に、910mmピッチで均等に連続する木造フレームを架ける。地上5m以上は、高度斜線によって一様に切り取られた屋根が周囲の家並みと連なる。

隣地側にも同様の斜線が掛かるので、そこに向けて東端から西端までのトップライトを設置することで、密集地では貴重な、日中の光を半永久的に取り込むことを可能にした。片流れ棟を延長して真夏の直射光は遮りつつ、終日太陽の恵みを享受できる断面形状とした。またトップライトの一部は、屋根面近くの定常風を利用して自然換気を促す開閉窓としている。特に日照が届きづらい下階の中央部は、動線の交点を集中させつつ吹き抜けを設け、自然光のもとに家族の気配が繋がる計画とした。
道路と裏庭で南北の空地を確保したうえで、そこに向けた長手のチューブ状の空間を分断しないように短手の耐力壁を配置し、視覚的にも環境的にも大きな一室空間としてプランニングしている。高低差を利用した気圧差換気を室内空間全体で行うことで温熱環境のムラを抑える。

光と風を取り込む筒の中に、床や天井を架け渡しながら諸室を割り当てていくと、それは街の谷間の地形のような空間となった。都市の狭間に住まうための洞窟は空に向かって開き、街と地続きの床の起伏が人間の居場所をつくる。
空は都市がつくり出した地形の大きな余白、地面は生活と連続する細やかな地形の連なりであり、これら2つの地形の接点に立ち上がった新しい住居は、変わらず都市に埋没した姿で建つ。（吉田州一郎、吉田あい）

A residence that maximizes light and wind through gaps in a densely populated residential area

The site is located in a densely populated residential area in the city center, where a group of housing units sold simultaneously about 30 years ago began to be relocated and reconstructed due to generational change. The front road is a 2-section road, and the back side is a cliff with a drop of less than 4 m. We aimed to create an elongated house while sewing through the various restrictions on the site, which has a frontage of 5.4 m and a depth of less than 16 m in the east-west direction, in the shape of an eel bed.
Between the setback of the road and the separation distance from the cliff, a continuous wooden frame is erected evenly at a pitch of 910mm. Above 5 m above ground level, the roof, cut off uniformly by the elevation slopes, is connected to the surrounding houses.

The same oblique line is also applied to the neighboring side of the house, and by installing top lights from the east end to the west end toward this side, it is possible to capture daylight semi-permanently, which is precious in a densely populated area. The single-sloped ridge was extended to block direct light in midsummer, but the cross-sectional shape allows the building to enjoy the blessings of the sun throughout the day. Part of the top light is a window that opens and closes to promote natural ventilation by utilizing the steady wind near the roof surface. In the central part of the lower floor, where sunlight is tough to reach, the intersection of traffic lines is concentrated, and an atrium is created to connect the family under natural light.
The short bearing walls are placed so as not to break up the long tube-like space facing the street and the backyard, and the space is planned as a large one-room space both visually and environmentally. The unevenness of the thermal environment is suppressed by using air pressure differential ventilation throughout the interior space, utilizing the difference in height.

When the various rooms were allocated in a tube that let in light and wind while bridging the floor and ceiling, it became a space that resembled the topography of a city valley. The cave for dwelling in the city’s narrow space opens to the sky, and the undulations of the floor connected to the city create a place for human beings.
The sky is a large margin of the topography created by the city, and the ground is a series of detailed topographies that are continuous with life. The new residence that rises at the junction of these two topographies stands unchanged, buried in the city. (Kuniichiro Yoshida, Ai Yoshida)