019.妻有 02.家
019.Tsumari 02.House

2023年3月5日

日本有数、それ故、世界有数の豪雪地の妻有で、家を決定するのは雪。雪への対処から、家の形も細部も導かれます。

Tsumari is one of the snowiest areas in Japan, that is, one of the snowiest areas in the world. The snow determines the shape and details of the house.

国の重要文化財に指定されている星名邸の冬の外観。せがい造りによる梁が、屋根の軒を支えている。ご当主の話では、広大な庭の樹木の雪囲いもたいへんで、毎年、100万円以上掛かるそうだ。
See the exterior appearance of Hoshina Residence designated as the national important cultural property in the winter. Beams by Segai-zukuri support the eaves of the roof. The head of the family said that the snowshed for the trees in the vast garden was also so hard that it costed more than 1 million yen every year.
https://goo.gl/maps/gKPjkHYoowhEEweR9

国の重要文化財に指定されている星名邸の夏の外観。せがい造りによる梁が、屋根の軒を支えている。
See the exterior appearance of Hoshina Residence designated as the national important cultural property in the winter. Beams by Segai-zukuri support the eaves of the roof.　
https://goo.gl/maps/gKPjkHYoowhEEweR9

豪雪地のため、近年までプレハブメーカーの進出も限られ、新築でも、地場の工務店による在来工法の家の存在感が大きい。その家が配慮するのは、大まかに「上から加わる雪」「横から押す雪」「下から引っ張る雪」。

ふつうの地域の屋根は、壁から出た軒を、たる木が支えますが、「上から加わる雪」に配慮する豪雪地の妻有では、梁を軒先までしっかり出して、屋根の雪の重みを支えます。せがい造りと呼びますが、東北地方の豪雪地にも同じ呼び方が残り、雪国で共有された造りかもしれません。

最近の家では、刃物のような鋭い棟が立ち上がります。これは雪を屋根の両面に切り分ける仕掛けで、これがないと、両面の雪が一つながりになって迫り上がり、家に悪さをします。屋根に谷を設けるのを嫌うのも、雪が滑り落ちず溜まってしまうため。

横から押す雪は、降雪と雪下ろしで家の脇に積み上がる雪。その雪の圧力で窓ガラスが割れるのを防ぐために窓の外に取り付けるのが雪囲い板で、窓脇には雪囲い金物が必須。最近の家で1階を高床にするのも、横の雪で１階が暗くなる生活を改善するため。雪国の特例で、高さ1.8mまでは、床下が延床面積に算入されません。1階の生活環境は改善されましたが、雪が消えても高齢者が外に出にくく、寝た切りが増えた話もあるのが難しいところ。

下に引っ張る雪（沈降雪）とは、積み上がった雪が春先に溶ける際、雪に引っ張られて屋根が壊れてしまうことで、雪下ろしを頻繁に行う道路側を除けば、屋根の軒を高くして、積み上がった雪とつながらないようにするのが一般的。ふつうの地域の家のプロポーションに比べると、１階の庇で分節されないので、立ちが高く見えます。

そういう雪＝水との関係でおもしろいのが、蔵。漆喰は火には強いが水に弱いため、妻有では、雪上となる高さまで、漆喰を板壁で覆い、屋根も漆喰の上に束を立てて、もう一重木造の屋根を掛け、雪や湿気から漆喰を守ります。ふだんは板が漆喰を守り、火が出た際には、板壁と木造屋根を取り壊して、漆喰が、火から蔵を守る仕組みです。

大地の芸術祭の作品として、建築を設計した際のこと。プレゼンの際、役所の職員からは、案について、一切の文句も意見も出ませんでした。唯一の関心が、雪のディテールの不十分なところがないかどうか。妻有では、人も雪に司られていました。

Due to the heavy snowfall, prefabricated manufacturers could not advance to Tsumari until recently, and local contractors using traditional construction methods have a strong presence in new construction houses. The house considers mainly "snow applied from above," "snow pushed from the side," and "snow pulled from below."

In other areas, rafters support the eaves that protrude from the walls. Meanwhile, in Tsumari, which considers "snow added from above," the beams extend by the edge of the eaves to support the weight of the snow on the roof. It is called the Segai-zukuri, and the same name remains in the heavy snowfall areas in northern Japan, and it may be common in the snow country.

In modern houses, sharp ridges like blades stand up. It separates the snow on both sides of the roof. Without it, the snow on both sides comes together and piles up, causing damage to the house.

The snow that is pushed from the side means the snow that accumulates on the side of the house due to snowfall and snow removal. Snow guard plates and hardware for the plates are attached on either side of the windows to prevent the window glass from breaking due to the pressure of the snow.

Recent houses raise the first floor to improve the life of the first floor, which had been dark due to the snow on the side. As an exception in snowy regions, the underfloor up to a height of 1.8m is not included in the total floor area. The living environment on the first floor has been improved. However, even after the snow has thawed, it has been hard for the elderly to go out, and that caused an increase in bedridden people.

The snow pulls the roof and breaks it when the piled-up snow melts in early spring. AA roof at a high position avoids from connecting with the piled-up snow. The proportion of Tsumari house looks taller than ordinary houses in other areas.

As for the correlation between snow = water and house, a storehouse is characteristic. Plaster is strong against fire but weak against water. The boards, which cover plaster wall up to the top of the snow, protect the plaster. Bundles are placed on top of the plaster roof, and another wooden roof protects the plaster from snow and moisture. In the event of a fire, the wooden wall and roof are demolished, and the plaster protects the storehouse from fire.

I designed the architecture for the Echigo-Tsumari Art Triennale. In the presentation, the officials at the city office never complained or expressed any opinions about the design. Their only concern was whether the details for the snow were perfect. In Tsumari, the snow also ruled people.

妻有の家と雪の関係 / Relation between a house and snow in Tsumari