Taking on the Challenge of Self-Building

Recently, I have been seeing the term "self-build" more and more in housing magazines and other media. I myself built my own home in Nasu 22 years ago as a self-build project, triggered by seeing cottage gardens in the Cotswolds region of the UK where I was studying (Photo 1). I was so moved by the British cottage gardens, where the house and garden seem to be integrated, that I decided to study house building from scratch and challenge myself to a self-build with my wife. The experience of building a house changed my outlook on life, and later, in 2003, I founded a design company called Half Build Home in the same Nasu area.

The motivation for establishing the company was the thought that there was a potential demand from other people who, like us, wanted to build their own homes with their own hands through self-building. I commercialized a system to support this at the company. We have worked on about 130 houses so far, but recently I feel that DIY programs on TV have increased and it has become much more familiar than it used to be.

Did you and your wife build your entire home yourselves, Mr. Aoki?

That's right. My wife and I finished everything, including the roof and exterior walls. For the roof, we used a wood called Red Cedar Shake and finished it with wooden shingles. We also created the entire garden ourselves.

Amazing. How old were you then?

In my 30s. I suppose I could do it because I was young.

Your wife must be happy with a house so rich in greenery. Why was it Nasu?

I had wanted to live in the countryside for a long time. I had gone to look at land in Karuizawa and Yatsugatake, but a senior who happened to be running a pension in Nasu said, "There's some good land here," so I decided on the spot.

What kind of people are common among Half Build Home's customers?

Our customers are largely divided into two orientations. One is people who want to build a house with their own hands with the same kind of commitment we had. They come to us because other contractors or house makers can't do it. The other is customers who have a small budget but don't want to compromise, so they work hard to build it with their own hands.

Mr. Oka, you are also in the middle of self-building your own home, "Arimasuton-biru (Ant-Grasshopper Building)," on land along Hijirizaka in Mita. I was surprised to hear that you started building in 2005 and are still continuing to build it with reinforced concrete. What was the trigger for you to build it yourself?

Until I was 30, I lived a life where I worked as a craftsman at construction sites for about half the year, and spent the other half traveling around Japan on a bicycle sketching architecture. At the sites, I experienced various occupations such as civil engineering, rebar work, formwork carpentry, and scaffolding. I didn't have any major setbacks, and life was going pretty much as I wanted.

Alongside that, every year I attended a private school called the Takayama Architecture School, which was started in 1972 by the late architect Yasuo Kurata, who taught at Hosei University. There, I also learned things like the philosophy of an architect.

However, around the time I turned 30, my health broke down, and my spirits sank to the point where I thought I had no choice but to give up my dream of becoming an architect.

Despite being at such a rock bottom, I got married, and at one point, my wife said to me, "Let's build a house for us to live in." If I had been honest, I could have said, "That's a bit impossible for me," but in a moment of madness, I declared, "Leave it to me, I'll build an amazing house for you" (laughs).

That one sentence decided your life, didn't it? (laughs).

That said, at first I didn't know what to build. For the time being, I bought the land along Hijirizaka around 2000, but it was five years later that I started construction.

What were you doing for those five years?

I was constantly agonizing over what to build and how. I finally made up my mind when I decided that there was no point in worrying any further and that I should trust what I had learned up to that point.

Even so, five years is a long time.

Yes. When I first started building, I was just moving my hands blindly, but gradually the shape began to emerge, and I slowly understood my own way of building. Then, more people started coming to see it, and they began saying things like, "This part is great!" about things I hadn't even noticed myself. I've continued building while regaining my confidence in that way, leading up to the present (Photo 2).

At the Shonan Fujisawa Campus (SFC) where I work, we are also moving forward with a project called "Student-Built Campus (SBC)," in which students participate in construction. Since SFC is a suburban campus, it was a long-cherished wish to build accommodation facilities where students could stay while conducting research and education. Therefore, this project was called "Miraisozojuku (Institute for Designing the Future)," and construction plans were progressing around 2008 with a design by Fumihiko Maki.

However, the Lehman Shock occurred just as we were about to decide on a contractor, and the project stalled. The plan started moving again in 2015, when SFC celebrated its 25th anniversary. Around the previous year, the idea came up that if there were no contractors, we should just build it ourselves, and it developed into a project to increase the number of small one-story wooden buildings over about five years. Currently, all seven buildings are completed (Photo 3).

SBC aims to connect to learning and be useful for research by having students themselves involved in design and construction while building accommodation facilities. Under the concept of an "unfinished campus," we decided to learn about destroying at the same time as learning about building, and even now, five years after the initial plan, it continues with students making furniture and changing interiors in classes. One of our goals is to continue this for 20 or 30 years. I also find it interesting to practice "destroying while building" within the university system.

How have the students been involved?

Mainly in design. While faculty members supported aspects of structure, regulations, and technology, students drew blueprints and made models. On the construction side, we created a scheme where students could participate in the form of part-time work for a construction company so that they would not incur liability for defects.

As a part-time worker, how far can they get involved?

At first it was just painting, but we gradually expanded the scope while building the seven buildings, and in the end, they were also in charge of installing structural hardware and braces to reinforce the structure.

In our company, the owners themselves handle the interior work by having our staff provide hands-on lectures and support on-site.

If such schemes were to spread more, house building would become more fun, but in Japan, there is also the circumstance that drawing the line between the owner's responsibility and the construction company's responsibility is very difficult. In the case of SBC, if this could be viewed more broadly as student learning and done regardless of existing systems and defect liability, the scope of learning would surely expand.

That's true. Changing regulations from the root takes a tremendous amount of effort. The method of involving students as part-time workers was born from the idea of hacking the existing system. In other words, it's the idea of reinterpreting a certain system for a use different from its original purpose.

It's an idea born from focusing on student learning.

Exactly. From the position of a part-time worker, the insurance system can be applied, and it's a mechanism that is a win-win-win for the students, the university, and the construction company.

Under the current Building Standards Act, any floor area of 10 square meters or more requires a building confirmation application, and the rule is that the designer must perform construction supervision and undergo a final inspection. I feel this is also becoming a barrier to self-building. For example, why is it necessary to have a building confirmation application, designer's construction supervision, and a final inspection just to build a 20-square-meter shed on a large 300-tsubo plot of land in the countryside at one's own risk?

On the other hand, a timber shortage called the "Wood Shock" is currently occurring worldwide. This is said to be caused by the increased demand for DIY in the US while people were staying at home. In other words, in Europe and the US, people are easily building houses, sheds, and garages on their own land on holidays, and I think the legal restrictions are quite different from those in Japan.

Nowadays, the number of large home centers in Japan has increased, and materials have become easier to obtain. Detailed information for building structures can also be easily gathered on the internet, and I myself watch YouTube all the time. It's a really great era for self-building, so it's a waste, isn't it?

Compared to when I was building my own home, the amount of information is like night and day. Of course, there is a lot of fake information, so caution is necessary.

I think people who can make or fix the things they use with their own hands like that have a high probability of surviving even in critical situations.

However, current Japanese society has somewhat abandoned half of that. A society without diversity is also a society that is highly likely to decline due to environmental changes. I feel that the fact that laws have become rigid is not unrelated to survival strategy when viewed from a broad perspective.

I truly think so too.

In 2005, when I started building Arimasuton-biru, the structural calculation forgery problem, the so-called Aneha Incident, occurred. That triggered legal regulations to become very strict. Until then, the government had a movement to leave confirmation applications to the private sector, but the awareness of contractors and craftsmen changed significantly after this.

After that incident, the Act on Promotion of Quality Assurance of Housing (Housing Quality Assurance Act) was created. It required construction companies and contractors to provide financial backing, or collateral, to guarantee against defects for 10 years.

However, since the Housing Quality Assurance Act is a law based on the premise that a construction company builds the house, self-building is not taken into consideration. Even a small self-build with a construction cost of about 5 million yen is subject to the Housing Quality Assurance Act. Of course, it is a law to protect consumers, but the reality is that it conversely restricts people who want to build their own homes casually.

As Mr. Oka says, there are more large home centers now, and it's an era where it's easy to build. Many people can now obtain various information from the internet. Despite that, only the regulations are still determined in a centralized manner. There are too few options for building structures.

By the way, Mr. Oka, why did you try to build in Mita, and with reinforced concrete, which takes time and effort?

I originally liked youth towns like Koenji and Shimokitazawa, so at first I was resistant to Mita. It's a business district, and I felt a high hurdle in Keio being nearby. I settled on Mita because there happened to be land that we could somehow afford with our own wallets. If there's an advantage, it's that the Architectural Institute of Japan is nearby, so various acquaintances stop by.

There was no deep reason for choosing reinforced concrete construction either. Reinforced concrete is called "RC," right? When I learned that during my technical college days, Kiyoshiro Imawano's RC Succession was popular (laughs). I was a big fan, and at one point I thought that if I created a company called "RC Manufacturing Plant" to make reinforced concrete, I might be able to become friends with Kiyoshiro.

It certainly isn't a deep reason (laughs). But I think there is a big leap between the decision to buy land and build with RC, and trying to do it all yourself.

One reason might be my experience at construction sites. Working at sites for general contractors and house makers, I saw craftsmen doing quite sloppy work in various places. When you see that, you really can't pay them out of your own pocket.

Another reason is that I used to be a dancer. In particular, I was dedicated to expressing what I felt on stage through improvisation. I thought this methodology was quite good, and I wondered if I could do the same with architecture. RC, which allows you to freely change the form while building, is improvisational and I thought it was the perfect material for me.

Mr. Oka, you are facing your own sensibilities honestly. I feel that even if the shape is vague, if the desire to build is not at the origin, self-building won't be interesting.

When you keep building for a long time, you start to doubt the methods you thought were correct until then. If you try a different method as an experiment, it often works out surprisingly well, and you can find a new path.

For example, I recently discovered that if you apply vinyl to the inside of the concrete formwork, the surface becomes smooth. Furthermore, after pouring concrete, the formwork is usually removed within a few days, but if you leave it for two or three weeks, the finish becomes better. I heard this is because if you let the concrete rest without exposing it to wind and rain, a glassy substance is generated within the cement. Discovering things that aren't even taught in school is very thrilling. That's what I enjoy the most.

What's important is the thought, commitment, and sensibility that you want to make something like this. If you just collect how-tos without that, the good aspects of self-building—the handmade feel that professionals can't produce, or the creations with broad and free ideas—won't be born. As a result, it ends up being a self-built house that looks like it was made by a poor carpenter.

I think there are many people in the world doing self-building. I have a friend in the architecture industry who lives in Hakushu, Yamanashi Prefecture, and he says there are many people around him who move from Tokyo to build houses. But apparently half of them fail.

Why is that?

Apparently, they become unable to do anything halfway through and give up.

As a result of starting everything from pouring the foundation themselves, it takes too much time, and many people are forced to give up because the exposed timber rots. To prevent that, our company always handles everything from the structural work to the weatherproofing and exterior wall work. we leave the interior work, which does not involve the structure or leaks, to the owner.

That means you hand it over in a skeleton state with the walls, pillars, and ceiling completed. In that case, the percentage of people who can see it through to the end increases significantly.

When you started building Arimasuton-biru, Mr. Oka, were you able to predict that it wouldn't be finished even after 16 years?

No, not at all. I told my wife, "It'll be finished in three years" (laughs). However, from around that time, I was also being threatened by self-building masters like architects Osamu Ishiyama and Terunobu Fujimori, who told me, "Your life will change."

There is a famous French self-build work called the "Palais Idéal du Facteur Cheval," isn't there? It's a building that Ferdinand Cheval, who was a postman, built by steadily piling up stones he picked up. Did you not originally intend to become like Cheval, Mr. Oka?

I had an admiration for people like Cheval or Simon Rodia, who built Watts Towers in the US by himself. I thought Japan would be in trouble if there weren't people who pushed boundaries like that. I never thought I would become one of them myself (laughs).

But in reality, I thought I could finish it in a few years. I'm not an amateur like Cheval or Rodia. I'm a first-class architects and building engineers (Ikkyu-Kenchikushi), and I had the pride of having been forged on-site.

In our case, we thought we could do it in six months. That was partly because if we didn't finish by then, our unemployment insurance would run out, but for some reason, at first, there's a bit of wishful thinking, and you convince yourself it can be done in a short time. In reality, it took us ten months.

Ten months is fast!

No, by the end, my legs, lower back, and finger joints wouldn't move at all. It felt like I was crying while doing it at the very end. I think it was a challenge I could only take on because I was young.

Nowadays, half of the customers who come to Half Build Home build with a mortgage, but if you use a loan, there's a constraint from the bank that it must be completed in about a year. If it's self-funded, it doesn't matter how many years it takes, but for loans, we create a menu that ensures completion within a year.

For example, while estimating the customer's ability, motivation, physical strength, level of family cooperation, and time they can devote to house building, we try to ensure the house doesn't get too big, or if the interior work will take time, we suggest leaving it to a carpenter. A large part of our job is supporting them through every step of the process to lead them to completion.

Is the conventional post-and-beam construction method the most common?

It's 2x4 (two-by-four).

With 2x4, you can build without taking too much time. I used to work as a 2x4 carpenter, and I thought the person who came up with this way of building was a genius. I thought, what an easy-to-build system.

Speaking of systems, what I find most wonderful in Japanese architectural culture is Ise Jingu. The system of Shikinen Sengu, where the shrine buildings are rebuilt every 20 years, is said to have been established during the era of Emperor Tenmu, and I think the person who thought of this system was also a genius.

A 20-year span is just right for passing on traditions and techniques. I feel that if you leave a longer gap, there are parts that won't be transmitted.

I think a model where the physical matter is replaced every 20 years while remaining Ise Jingu as a system is close to a living organism. We humans also completely replace ourselves at the cellular level compared to a year ago. Inside the body, we are creating new cells while destroying old ones. But strangely, our personality is maintained, isn't it?

If we look at Shikinen Sengu not just as the shrine buildings but as a single system including the surrounding people involved, the man-made object of architecture starts to seem like a human body.

The opposite of this architecture is the Parthenon in Greece; that temple can be called a model that entrusted the permanence of architecture to the substance of marble. Looking at it through this contrast, I think a certain idea of sustainability similar to a living organism emerges from the act of self-building or building while destroying.

I see.

When environmental issues become more serious and sustainability is discussed more severely, this model of a living organism might gain reality in the architectural world. Then, legal frameworks might be established, such as requiring rebuilding every three years, or exempting minor architecture from the Housing Quality Assurance Act. I feel that laws might only start to change once we reach that stage.

That's an interesting point. When people participate in construction and come to understand the structure and mechanism, customers become able to perform maintenance themselves. Since they understand the reason why cracks appear in plaster walls, complaints disappear, and they understand that it's natural for wood to warp.

In normal residential construction where the owner does not participate, even a minor defect leads to a complaint. Because of that, some construction companies stop using solid wood, or mix adhesives into plaster to prevent even slight cracks. That's a cat-and-mouse game. I wish more people would get involved in house building so that such instances would decrease.

It's something you don't know until you actually try it, but self-building is a series of discoveries.

I truly think so.

The construction site is a different world, so it's full of new discoveries every day. Not only do your technical skills improve, but you also get a glimpse into the worldview of craftsmen, and that alone provides a lot of learning. This experience is truly significant.

Yes, there is learning. I've worked at various sites, but one of the reasons the Arimasuton Building takes so much time is simply because there's a lot of work.

On a normal site, someone else does the work other than what you're assigned. For example, on a site, there's an older laborer sweeping with a broom, and back when I was a craftsman, I didn't pay any attention to such people. However, when you're building alone, you have to do even the minor cleaning yourself.

I always eat breakfast thinking, "Today I'm going to do this first!" but then I realize, no, that's not it. I remember that since it's Tuesday, I have to put out the burnable trash first (laughs). Because of those chores, I can't immerse myself in the work 24/7. When you're alone, these things also become a learning experience.

When you participate in a construction site, you deeply understand the hardships of people doing various jobs in society, especially the hardships of people on-site. All our customers say their outlook on life changes, and I truly believe that.

How did your own outlook on life change, Mr. Aoki?

After graduating from university, I worked for a large corporation, where everyone around me was also a university graduate. From this world of limited social interactions, I suddenly went to Nasu and started dealing with foundation contractors on-site.

Of course, I experienced culture shock at first, but as I became closer to them, I learned from their ways of thinking and living. I began to see things from a completely different perspective than my previous human relationships.

Mr. Matsukawa, what do you think when you look at students today?

Currently, the field of architectural design is moving toward digitalization, but when students design furniture with CAD or other design software, they assemble 3D models with things like zero-millimeter thick boards or points with zero length.

But in reality, that's impossible. To make a chair, the board has thickness, and to connect wood, you have to design the joints as well. Then, when students are faced with the actual object, they find that the joints here don't work out.

It's obvious when you think about it, but I'm afraid that without experiencing that struggle with physical objects, we might produce architects who don't consider weight or tactile sensation. My specialty is digitalization, but looking at the students, I think it's just as important to put effort into the DIY world—that is, the struggle with physical objects.

Our customers start with installing insulation, then add floors, ceilings, and doors, and finally finish with painting, plastering, and masonry; they do it more carefully than a carpenter would.

That makes sense.

When we carefully teach them things like how to put insulation behind outlets or how to avoid creating gaps, they do a better job than a carpenter. Then the insulation performance becomes incredibly good. I don't think you can understand that level of satisfaction unless you've actually done it.

What is the overall cost of the Arimasuton Building? I imagine the cost would be quite high after 16 years of continuous construction.

I'm building it with borrowed money, but setting aside my labor costs, the material costs are low, so it's an amount I have a good prospect of repaying. I'm not making a giant sculpture, and once it's finished, a life without rent payments will begin, so the balance sheet works out.

Mr. Aoki mentioned loans earlier, but even if you try to challenge yourself with self-building on your own now, the system is set up so that if you receive full funding from a mortgage at the start, you have to complete it within a year. In that case, it can't accommodate cases like the Arimasuton Building that take 10 or 20 years to build.

So, for example, I'd like to see loan formats diversify, such as a system where you borrow 10 million yen in units of 1 million yen every year over 10 years and use it up each year. This is because in today's uncertain society, adapting agilely to ever-changing situations is important as a survival strategy. The self-building method of taking time to build and destroy provides hints for surviving modern society.

I don't know about a 10-year span, but certainly, the changes over 20 or 30 years feel enormous. In fact, many buildings from the bubble era have vanished without a trace, and right now, a super-high-rise office building is under construction behind the Arimasuton Building, but everyone must know that demand for office buildings will decrease in post-COVID society. Even so, they try to complete that building. This sense of rigidity is something we should reconsider.

Large-scale redevelopments are particularly high-risk. From now on, it will be important to be able to maintain a state where trial and error is easy.

Customers always ask me how much cheaper it is with self-building, and for 30 tsubo (approx. 100 sq meters), it's about 3 million yen. However, whether that amount is a gain for the customer isn't known until everything is actually finished.

This is because some people regret it, saying, "I shouldn't have done it." Such people naturally don't feel that it was good to have saved costs.

To put it a bit harshly, self-building is difficult for people who lack perseverance, grit, and planning skills. People who can push themselves even on Sundays and work strictly from 8 a.m. to 7 p.m. are the ones who finish in a year. Woodworking skills aren't that important.

Are there no people who can just run on pure excitement?

In interior work, the big jobs that require physical strength come first. That includes things like installing insulation and putting up ceiling and floor materials, but if you can break through that in three months, you can make it to the end. Conversely, if it takes too much time, motivation drops sharply. This is the worst thing. Staff encourage and help them, but it's quite difficult.

Struggling with physical objects is purely fun work, but it's not simple enough to get through on that alone.

The insulation, ceiling, and floor processes are monotonous, after all.

Perhaps people like you, Mr. Aoki, who take on the challenge with a wonderful ideal image, are the ones who can keep going until the end.

Yes. Especially if a couple is in step with each other, they'll usually be fine. The satisfaction with the finished product is also high.

The act of making itself is interesting, so if you can enjoy that, you can see it through, and it leads to the next thing. I also do it while feeling excited every day.

Regarding the act of "making," I think human prosperity has always been about continuing to make things with our hands. I think the reason we were making food, weaving clothes, and building houses was ultimately because things were scarce. However, entering the modern era, as soon as we became flooded with things, people stopped making them. To put it extremely, in this day and age, everyone is only touching their smartphones, right?

It seems to me that humanity is now at a turning point of tremendous change. We must not stop making things in order to survive, but things are overflowing. If that's the case, I think we have to invent a "making" that fits the current era.

That's philosophical. It's an interesting story.

So I'm saying let's think about "new making." When I say that, most people go toward art, but it doesn't have to be that. Because only the champions of craftsmanship can truly do art. Artists are the type of people from whom "making" wells up from within.

Until now, I hadn't been able to successfully link my specialty of architectural digitalization with the DIY world of struggling with physical objects, but recently I've finally seen a clue to connect them.

Humans coexist with various substances and fungi to maintain being human, but as I mentioned with the example of Ise Jingu, there is a way of perceiving architecture as a living organism. Taking inspiration from this, I am now creating a system to grow architecture like an ecosystem using computer programs. There, in order to materialize from information into physical space, human hands are needed as part of the system. At this point, a connection with the DIY-like world is born.

The moment humans stop making architecture, entropy increases and it faces thermodynamic death. I want to create "living architecture" by continuing to run a complex system of humans and machines. That is "new making" for me.

Speaking of "new making," I think it's very good for making things to be related to food, clothing, and shelter. For example, trying to grow vegetables in a garden, fixing a broken part of the house yourself, or having to sew clothes because they're torn—food, clothing, and shelter are easy to start with because they provide a trigger.

Moreover, we are in an era where you can share with many people that you made this kind of dish and it was delicious. Not everyone needs to build a house from scratch, but everyone should do more things related to food, clothing, and shelter themselves.

It would be great if everyone enjoyed making things more.