naf architect & design Inc.

１９７９年に開園したこの幼稚園は、相模原市津久井地区の高台にある。これまで多くの園児たちを迎え入れて地域に親しまれてきたが、増改築や老朽化で様々な不具合が生じていたこともあり、将来を見据えて建て替えることになった。

津久井地区は相模原市の中で最も面積が広く、幾つもの川や湖があり、山に囲まれていて人口密度は低い。多くの園児が送迎バスを利用しているというので、試しにそのルートを車で走ってみたが、１時間程度ではまったく回り切れない広さだ。中には待合場所で待っている１人の園児を乗せるためだけに設定されているルートもあり、それは・・・と思ったが、遊ぼうにも家同士が離れすぎていて会えない友達に、幼稚園に行けばたくさん会えるということで、多くの園児がバス送迎を熱望していると聞いて腑に落ちた。

開園して４０年以上経ち、卒園児は約８０００人で、その家族を含めると関係者は２万人を超えているのではないだろうか。津久井地区の人口が約２万６千人であることを考えると、そこに占める割合は相当なものになると想像できた。

ちなみに幼稚園でフリーマーケットや運動会などのイベントがある時には、それを楽しみにしている関係者が遠方からでもやってきて、随分な賑わいになるとのこと。成長した卒園児が保護者になって自身の子供を通わせることも多く、保育士の先生が卒園児という場合もある。つまり津久井ヶ丘幼稚園に通うということ自体が地域のコミュニティ形成と一体化しているような側面があり、通園先の選択肢が多様化している都心の場合とはかなり違う状況であることがわかった。

相模原市津久井地区の人口は２０００年頃をピークに減少が続いており、当然これから少子化も進んでゆく。これまで津久井ヶ丘幼稚園の場合は自然に「人が集まってくる」ことが前提になっていたが、少子化の時代においては、これまで以上に「人が集まりやすくする」ための工夫が必要だった。

したがって前面道路側に長い車寄せを設けて、道の駅のように２ヶ所の出入口から通り抜けができるようにしてアクセス性を上げた。複数の送迎バスがここに横付けして園児たちが乗り降りするのに十分な長さとし、脇を車が通り抜けできるように前面道路から６mセットバックさせている。竣工後はイベント時にキッチンカーが来てテーブルや椅子を広げたり、ごみ収集車を招いて社会勉強をしたり、さっそく様々な使い方が試みられていて、ここは「前庭」と呼ばれている。

以前に建っていた旧園舎は、前を車で通過すると連続する三角屋根が緩やかなカーブに沿って流れるように見えてくるのが印象的だった。新園舎では車寄せの屋根の先端をつまみ上げるように高くして、近づくと真っ先にそれが見えてくるようにしている。屋根の下に大型の車両が入る高さを確保するためでもあるが、前面道路に沿って印象的な屋根を備えるという点では旧園舎からの継承を意識している。

前面道路は地域交通の幹線で多くの車やバイクが行き来しているが、近年は東にできた相模原インターチェンジからやってきて行楽地の宮ヶ瀬湖に向かうなど、外来者の割合が増えている。同じく東にある橋本にリニア中央新幹線の新駅ができれば、交通量はさらに増すだろう。屋根の先端はその東に向けて伸ばしてあり、これから増えてゆく人の流れに対する視認性を上げられればと考えた。

新園舎は前面道路に沿って間口が広いこともあって、ホール棟と教室棟に分割し、その間を通り抜けて裏側に出られる配置としている。裏側と言ってもそちらが南側で日当たりがよく、周囲の山々への眺望がすばらしい。日々の外遊びはもちろんのこと、家族や関係者を招いて運動会ができる広さがあり、こちらは「園庭」と呼ばれている。

津久井ヶ丘幼稚園は長年に渡って鼓笛に取り組んでいて、ホール棟はその練習場を兼ねている。教室棟と分割することで音の干渉を減らすと同時に、ホールを単独で外部のイベントに貸し出せば、地域の集会所として開放性も上げられるのではないかと考えた。

教室棟には、これまでの活動が継承できるように旧園舎とほぼ同じ面積の保育室を４部屋つくった。そしてその脇に幅の広い廊下のような「拡張スペース」を設けている。保育室の引き戸を全開すれば拡張スペースと一体化して面積が増やせるつくりになっていて、認定こども園の基準面積を念頭に置いた可変性を持たせている。

保育室の引き戸を閉めると拡張スペースは小さなホールのような空間になる。天井を高くして園児が遊べるロフトを設け、様々な製作物が展示できるように広い壁面を設けた。仮にホール棟を貸し出していたとしても、教室棟単独で一定規模のイベントができるような融通性を持たせている。

屋根勾配はやや緩めの２．５寸として最高高さを抑え、外壁は杉の羽目板張りとしたうえで腰壁の高さで仕上げを切り替えて、見た目のボリューム感の軽減を試みている。園児たちが触って汚れたりする腰下は横張りで定期的な塗り替えやメンテナンスを前提にした塗装とし、腰上は縦張りで塗り替え不要の塗装としている。屋内も同じ考え方で、腰下はラワン合板張り＋塗装、腰上はクロス張りとしている。

建具はガラスを中残で分割し、腰下は曇りフィルムを貼って園児たちの気が散らないようにして、腰上は見通し確保のため透明なままにするなど、腰壁高さで機能の切り替えができるようにした。保育室のクロスは年齢ごとで柄の細かさを変化させ、フローリングはゾーンごとに目地や向きを変えている。大きなスケールから小さなスケールまで様々な切り替えや変化を与えることで、大人から子供まで、それぞれの興味や愛着につながればと考えた。

アクセス性・視認性・開放性によってこれまで以上に人が集まりやすい状況をつくり、可変性・融通性によって社会の変化に柔軟に対応できるようにすることで、人と建築との関わりが徐々に定着してゆく場になることを期待している。

建て替えという節目を経て、地域コミュニティと共に歩んできた幼稚園の歴史が、これからどのように書き加えられてゆくのか楽しみだ。

－中佐昭夫－

Name of the Project : Tsukuigaoka Kindergarten
Location : Sagamihara City, Kanagawa
Category : Kindergarten
Zoning use district : –
Fire protection specification : –
Structure : Wood construction
Number of stories : (classroom building) 2 floors above ground (hall building) 1 floors above ground
Maximum height : (classroom building) 5.521m (hall building) 6.061m
Maximum eave height : (classroom building) 5.392m (hall building) 5.932m
Frontal road : 11.000m on the north
Site area : 2330.880m2
Building area : (classroom building) 499.690m2 (hall building) 221.500m2
Total floor area : (classroom building) 462.070m2 (hall building) 178.870m2
Completion : July 29, 2022
Architect : Akio NAKASA(Principal Architect) , Teppei AMANO
Photographer : Toshiyuki Yano

This kindergarten, which opened in 1979, is located on a hill in the Tsukui district of Sagamihara City, a commuter town of Tokyo. It has accepted many children over the years and become a household name in the local community. As the existing kindergarten building started to have various issues due to ageing and having gone through a series of expansion and renovation, it was decided to build a new one as part of future-oriented strategy.

The Tsukui district is the largest in Sagamihara City, with many rivers and lakes, surrounded by mountains, and the population density is low. Since many kindergarten children use the shuttle bus, I tried driving those routes, but the area covered was too large to go around in a matter of an hour. There is a bus route set up just to pick up one child waiting in the pickup point, which seems too much but understandable considering the fact that houses are too far apart for children to see each other and that many children wish to have kindergarten shuttle bus to see many friends there.

It has been more than 40 years since the kindergarten opened and the number of children who finished the kindergarten is about 8,000. Including the families and friends of those who finished kindergarten, the number of people who had any relation with the kindergarten must be over 20,000, which is significant ratio in the population of the Tsukui district which is about 26,000.

When there are events such as flea markets and sports festivals in the kindergarten, the events are very much crowded with people who look forward to such events coming even from far. Those who attended the kindergarten would often send their children again to the same kindergarten or come back as the nurse. It can be interpreted that going to Tsukuigaoka Kindergarten is part of participating in the local community, which is very different from the situation in central Tokyo where the selection of kindergarten is so diverse.

The population of the Tsukui district has been declining since its peak around 2000, and as is the case for the rest of the country, the birthrate will continue to decline. Tsukuigaoka Kindergarten was operating under the assumption that people would “spontaneously come”, but in an era of declining birthrates, it is necessary to devise ways to make it easier for people to gather more than ever.

Therefore, we set up a long driveway along the frontal road and so that cars can pass through from two entrances like a rest stop to improve accessibility. This driveway is long enough to park multiple shuttle buses for children to get off and on and set back by 6 m which is wide enough for cars to pass beside parked buses. After the new kindergarten building opened, this driveway has been used in various ways such as having kitchen car, tables and chairs for events, or garbage car for social studies. This space is called “front yard”

Having a symbolic roof along the frontal rood is a feature inherited from the old building.
The old kindergarten building was marked by a series of triangle roofs which can be seen along a gentle curve when passing in front of the building by a car. The new building has a tip of roof over the driveway curved up as being held up so, making the roof the landmark when approaching the kindergarten. This shape allows enough height for large vehicles but it also meant to inherit the symbolic roof from old one which is notable from the frontal road.

The frontal road is a trunk road for local transportation, and many cars and motorcycles come and go, but in recent years, the percentage of out-of-towners has been increasing, such as coming from the Sagamihara Interchange, which was built to the east, and heading to Lake Miyagase, a recreational area. If a new station for the Linear Chuo Shinkansen is built in Hashimoto, which is also in the east, the traffic volume will increase further. The tip of the roof is extended toward the east so as to increase visibility by the flow of people who will increase in the future.

Since the new kindergarten building has a wide frontage along the frontal road, it is divided into a hall building and a classroom building, and between the two buildings is a passage to the backyard. Backyard not really back in a sense that it faces the south, enjoys sunshine and a great view to the surrounding mountains. It is spacious enough for not only daily outdoor play but also a sports festival with participation of families and friends. This space is called “garden”.

Tsukuigaoka Kindergarten has been teaching drums and flutes for many years, and the hall building is used as a practice area. By dividing it from the classroom building, the interference of sound can be reduced, and it can also be independently rented for external events to increase involvement to local community.
In the classroom building, four nursery rooms of almost the same size as the old building were designed as to enable the same activities to be inherited. And beside the nursery rooms is an “expansion space” like a wide corridor. When the sliding doors of the nursery rooms are fully opened, the floor area can be enlarged by integrating with the expansion space, which would satisfy the standard area of certified childcare center.

When the sliding doors of nursery rooms are closed, the expansion space becomes a small hall like area. The ceiling was set high to incorporate lofts where children can play, and a wide wall was set up so that various works by children could be exhibited. Even if the hall building is rented out, the classroom building is flexible enough to hold an event of a certain scale.

The roof slope has a slightly loose, which is 25/100 to keep the maximum height low. The outer walls are covered with cedar paneling, and the finish is changed according to the height of the waist wall to give a lighter impression on the seeming volume. The wall surface below the waist, which is touched by children and easily stained, is finished by horizontal siding and painted in a way that can be regularly painted for maintenance. The wall surface above the waist is finished by vertical siding and painted in a way that required no repaint. Interior walls employ the same principle, below the waist is lauan plywood finish + paint, above the waist is cloth finish.

For the fittings, the glass is divided in the middle from the waist height, below the waist is cloudy film finish so that the children are not distracted and above the waist is transparent to secure good view. The wall cloth in the nursery room has different patterns depending on the age, and the flooring has different joints and orientations for each zone. By giving various changes and switch from large scale to small scale, adults and children alike could have their own attraction and attachment to the space.

Accessibility, visibility, and openness will create a situation where people can gather more easily than ever before, and by enabling to respond more flexibly to changes in the society through variability and flexibility, I hoped the involvement of people and architecture will gradually be established.

I am looking forward to seeing how the new kindergarten building will add a new page to the history of the kindergarten, which has progressed with the local community.

– Akio Nakasa –