New build family home for Mr. Y in Yokosuka

–  Building a post and beam house using traditional Japanese construction methods –

Part 3: Foundation work

So, with the purification rituals out of the way and the Gods given their dues, it is now time to get on with the business of laying the foundations.

Even though the house will be built with traditional Japanese carpentry techniques, the foundation itself is generally made from re-enforced concrete. Traditionally, Japanese building foundations were large natural stones on which the structural pillars stood. This technique is called Ishibadate （石場建て）and sometimes we still use it today, but that is a blog entry for another time.

As I’m sure you know, the foundation is basically the concrete base on which the wooden structure sits. We build the foundation and drop the house on top, so to speak.

But first things first. We need to determine a level and this process is called the Mizumori-yarikata （水盛りやり方）.

We do this by placing upright wooden stakes called Mizukui （水杭）around the perimeter of the building site and then we attach a wooden board called a Mizunuki  （水貫）on one of the stakes. Using a laser-level we mark out the level on the Mizukui and Mizunuki. The level written on the Mizunuki is very important as this will be the reference point for all future surveying activities.

With the levels marked out, the concreters now have line to work from and can commence the site excavation in preparation for laying the concrete foundation.

Meanwhile, the carpenters go back to the workshop and get on with marking out the timber and cutting the joints…

横須賀市Y様邸新築工事

〜伝統構法で造る木組みの家〜

Part 3: 基礎工事

さあ！地の神様に工事の安全と家族の繁栄をお願いする儀式［地鎮祭］を終えるといよいよ基礎工事が始まります。基礎とは家を支えるコンクリートのかたまりのことです。地盤の上にまずコンクリートのかたまり（基礎）をおき、その上に建物がドーン！って乗っかるのです。

まずはじめに［水盛やり方］をします。家の外周に水杭（みずくい）を打ち込み、それに 水貫（みずぬき）という木の板を水平に取り付けていきます。そしてその板に建物の基準となる線や情報を書き込んでいくのです。これらの作業を［水盛やり方］といいます。

この［水盛やり方］を頼りに鳶さんが地面を掘ってコンクリートの基礎をつくっていきます。一方で大工部隊は作業場で［墨つけ・刻み］を行なっています。

 

 

New build family home for Mr. Y in Yokosuka

–  Building a post and beam house using traditional Japanese construction methods –

Part 2: Jichinsai (Ground-breaking ceremony)

Japan’s native religion ‘Shinto’ is founded on the animistic belief that all material objects, plants and natural phenomena contain a divine spirit or ‘Kami’ as they are called in Japanese. This concept is captured by the Japanese phrase ‘八百万の神’ (Yaoyorozu no kami – lit. eight million gods) which idiomatically expresses the uncountable number of Shinto gods.

Given this abundance of gods, it is inevitable that some of them will need to be appeased before building a house. You could say it is a bit like getting building approval from the local government only on a more spiritual level. This is why we conduct the ‘地鎮祭’ (Jichinsai) ceremony which is the Japanese equivalent of a ground-breaking ceremony. The purpose of the Jichinsai is to receive divine permission for using the land while also praying for a safe construction and the prosperity of the family that will live in the house.

A local Shinto Priest is invited to conduct the ceremony. The priest performs various rites such as giving offerings to the gods, saying prayers and purifying the land. The client then breaks the first ground using a ceremonial spade or hoe. This ceremony allows both the carpenters and the client to consider the gravity of the undertaking on which they are about to embark.

This ceremony has a long history in Japan but it is by no means compulsory or enforced. Just like visiting a Shinto shrine on New Year’s Day, the jichinsai is deeply ingrained in the Japanese culture. There is no law saying Japanese people must conduct the ceremony but people just do it anyway. To not conduct the ceremony or to not celebrate the new year at the shrine would just feel strange.

Having said that, these days some people opt for a more simplified version of the Jichinsai or simply do not do it at all. Some might say that it is just a ceremony but I think there is something comforting in maintaining this part of Japanese culture so let’s keep the Jichinsai alive!

When it’s all said and done, the jichinsai is a good opportunity for the client to meet the carpenters before construction commences.

横須賀市Y様邸新築工事

〜伝統構法で造る木組みの家〜

Part2: 地鎮祭

日本には八百万神という言葉があり、この世の全てのものに神様が宿ると信じられています。そして地鎮祭では家を建てる土地の神様を祝い鎮め、土地を使うことに対する許可を得ると同時に工事の安全や無事、建物や家族の繁栄を祈る儀式なのです。

また、「とこしずめのまつり」と読むこともあります。土地の氏神様の神主を招き「お供え物」「祝詞」「御祓」などをして土地を浄め、初めて施主様が鍬や鋤をいれます。「えい！えい！えい！」と気持ちを込めて鋤をいれるとこれから建つ家に対する想いがより一層深まります。

昔から新築工事を始める前に行われてきたこの儀式ですが、必ずやらなくてはいけないものではありません。みなさんは新年を迎えると、神社へお参りをしに行きますよね。それと同じようになぜか当たり前のように行われてきました。初詣をしなくてはならない。とか、地鎮祭をしなくてはならない。という法律がある訳でもないのに・・・ですので、ほとんどの方は地鎮祭を行っていると思いますが、やらなかったり、簡略化している方も最近は多いそうです。 でも日本の文化なので、やらないとなにか気持ち悪い気もしますよね。私たちはこの文化を受け継いでいきたいと考えています。着工前にこの工事に携わる職人さん達と顔合わせをするいい機会でもあります！

#fujimototraditionalcarpentry #木組みの家 #地鎮祭

Hello everyone, it’s been a year since I posted an article last time, apologies! Fortunately, we have been very busy with lots of projects, opening a restaurant and also welcomed new members in our team!!! Please check our profiles in ‘About’ section.

We are excited to introduce you all our new project.

New build family home for Mr. Y in Yokosuka

–  Building a post and beam house using traditional Japanese construction methods –

Part 1: Ground survey

For any new build, the ground survey is a vital for creating a building that will last the test of time. So what is a ground survey? Well, as the name suggest, a ground survey is the practice of investigating the qualities of the land on which the house will stand. By assessing the topography, soil, history of the ground we can then design and build suitable foundations.

So why is this important? Put simply, building a house is essentially the same as placing something extremely heavy on the ground. If the ground is soft then naturally, the building will sink and inevitably begin to lean. By conducting a ground survey we can determine how soft the ground is and accordingly, what needs to be done in order to strengthen the ground so that it may give stability to a building that can weigh in excess of 70 tons.

Luckily, the ground on which Mr Y’s house is to be built is very strong. If it wasn’t, we’d have to make many improvements and this is never a cheap exercise. This is why it is so important to choose wisely when purchasing the land for your new home.

Two things that you should consider when choosing land are height and history. In Japan high ground is generally the most stable. The Japanese people have known this for countless generations and therefore, it is common to see the remnants of old foundations on vacant land situated on high ground. As the years go by this ground becomes stronger and stronger.

Gravity dictates that water will pool at the lowest point of a given topography and so low ground is generally soft and muddy. In Japan, low ground that is close to rivers and swamps has traditionally been given over to agriculture.

Having said that, it isn’t always true that high ground is strong ground and this is where history is important. Even high ground, when recently excavated is far weaker than ground that has been continually built upon for thousands of years.

To those of you thinking about building a house, my advice is this: while layout and fittings are important, in the first instance, it’s a good idea to give serious consideration to the ground on which the house will be built.

It’s only started, stay tuned on the progress 🙂

こんにちは！前回の投稿から一年以上経ってしまいました・・お陰様で色々なプロジェクトを任せて頂いてる上に、レストランをオープンしたり新メンバーを迎えたり、てんてこ舞いの一年だったのです。

ですが心機一転して、最近始まったこの新プロジェクトに関してこれからリアルタイムでブログにしていこうと思います。チェケラウト！

横須賀市Y様邸新築工事

〜伝統構法で造る木組みの家〜

Part1 地盤調査

地盤調査とはその名の通り家を建てる土地の地盤の状態を調べることです。なぜそんなことをするかというと・・建物自身の重さは数十トンにもなります。建物とはそれだけ重いものが地面に置いてあるのと同じ状態なので、その地面が柔らかければ沈んでしまいます。沈んでしまえばもちろん建物は傾きます。そうならない為にも地盤調査をし、建築可能な土地かを調べます。

今回は幸いにも地盤の強い土地でした。もしこの地盤調査で地盤が軟弱な場合には地盤の改良が必要になってきます。しかし地盤の改良は決して安くはありません。なので、土地探しの段階で、ある程度地盤が強いかどうかを見極めることが大切になります。

地盤の強い弱いに深く関係しているのが、地形の高さや歴史です。高地の方が古い地盤が多くみられます。地盤は年月を重ねるごとに強度を増していきます。また、水は低いところに溜まるので低地の地盤は柔らかい傾向にあります。海、川、池、田んぼなどの土地の近くの地盤も柔らかいことが多いです。また盛り土をした土地や埋立地も地盤が強いとは決して言えません。

何万年、何十万年と経った地盤と、つい数十年前に埋めた地盤とでは強さが違うのは簡単に想像できると思います。最初は設備や間取りなどに気が向いてしまいがちですが、建ててから見えなくなってしまう部分にこそ、初めに視野を向けることがいい家を建てるために必要なことなのです。

次回もお楽しみに！