一級建築士事務所 seki.design / セキデザイン

House in Suma

トップ写真

Life embraced by materials of mother-nature

A house built through the construction management system after the winning at the design competition with three architects. The design theme is “earth, wood and fire”. Particularly, natural materials are in use.

A large dining & living room with a so-called “earth floor” is accessible from outside as you wear shoes on. A 280mm x 280mm pillar stands in the center there. The counter table, dining table and the “hanchiku-heki” (= a wall built in rammed earth techniques) behind the fireplace are assembled with solid Japanese oak woods, which produces depth in space.

ダイニングよりリビングを見る:
玄関からダイニング、リビングに渡ってタイル貼りの土間が続きます。土間は30mmと肉厚な桧板の階段、版築壁、薪ストーブが配され、暮らしのアクセントとなる場所です

The “earthen floor” made of floor tiles gives many options to use; decorating with branches of cherry blossom in a huge vase in spring, cooling a water melon in a wooden basin in summer, etc. The fireplace plays a key role in winter. Even a pile of wood sticks under the stairs produces a scene as in a resort villa in a winter mountain.

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平面図

“Hanchiku-heki” - Encountering with Ms. Kumiko Hatanaka -

“Hanchiku-heki” is a firm earthen wall built in ancient techniques, and the techniques are also applied to the building foundation. Originally, it was almost made only of soil and stone (gravel) and a little bit of lime is sometimes mixed with them. Currently, however, it is often seen with cement mixed in. Its construction is very simple; pour soil in a wooden frame up to 10-20cm at one time, press it with sticks and compress it down to the half, to build the wall up by repeating these steps.

Ever since we learned about “hanchiku-heki” from a magazine, we have been dreaming to implement it in our design at some point, but did not know how. One day, while talking to a wood stove vendor, we found out that a “hanchiku-heki” could be a fireproof wall and that they knew one person in Kobe who researched about it. Thus, we met Ms. Kumiko Hatanaka.

Ms. Hatanaka has taught as lecturer at Kobe Design University and now runs her own design office. She built her lab in the rammed earth techniques when she was a student, and applied the techniques for a part of her own house as well. First of all, she lectured us about the basic techniques. Then, we developed the blend ratio of materials, the kinds of soils and the ways of pressing and firming the rammed earth, to make various samples. As comparing and reviewing the samples, we worked all together with the staff members of the housing contractor and came up with a good result; a little rough and loose compressing would give more richness in appearance of the wall instead of careful and strong compressing.

The wall used for the actual house was built by Ms. Hatanaka, the client, the housing contractor and us all together as if we were having a workshop. A mold was created as not to give much impact on the main building structure. Soils were blended outside, brought in, poured with buckets into the mold and pressed to firm. These procedures were repeated for some dozen times. We all enjoyed that at the beginning but lost motivation as the wall became higher and difficult for pressing (It is said that in ancient times, these works were done by slaves!). Although all of this went through for 2.5 days (1.5 time faster than a normal case), the result was satisfactory. Moreover, we became more attached to this house through the efforts we all made together.

正面外観:
縦波のように格子の角度を変えていくことによって趣のある表情をめざしました。斜めに張り出したモダンな屋根の軒にも杉板を張り、格子と調和した「和」のテイストを意識しています。駐車スペースにはヨーロッパの枕木をあしらっています

北西面の外観:
須磨の美しい山並みを望むことができます

正面外観

リビングから吹抜けの見上げ:
タイル貼りの土間にはこの家の主役・薪ストーブが置かれています。冬の夜には家族でゆらめく炎を眺めながらのひとときを

和室よりリビングダイニングを見る:
家の中心には280mm角のどっしりとした大黒柱が鎮座しています。この材木は、材木市場でクライアントと一目ぼれしたものでした。基礎から屋根まで通る、6mの一本もので、決して飾りではなく、家の重心で大黒柱本来の役割を発揮しています。背割りは埋木され、表面は丁寧にきめ細かく仕上げられているため、つい手で触れたくなってしまいます

吹抜けを見上げる:
大黒柱とそれに取りつく梁を吹抜けに配し、迫力と安心の感じられる空間にしました

2階から1階を見る:
階段の板にも30mmと肉厚な桧板を使っています。自然素材の力強さに包まれる空間です

ダイニングテーブル:
この一枚板のテーブルも、クライアントとともに材木市場で吟味して仕入れた70mm厚のナラ材で、棟梁によって丁寧に仕上げられています

photo: akiyoshi fukuzawa