Architect wants to end nail-hammer cycle

Passive House expert's passionate pursuit of new education started out by sticking out

by Kris Kosaka

Miwa Mori, president of Key Architects, thinks a lot about nails, both as part of her profession and as her philosophy about life.

“It is really tough to be a woman company president in Japan, but that is why I considered carefully the timing of my return to Japan. If it had been even two years earlier, it would have been more difficult,” she said. “We have that saying about the nail that gets hammered down — but if it is sticking out enough, if you are different enough or established enough, nobody can hammer it anymore.”

Mori’s life supports her views. She left Japan when she was 22 to study architecture in Germany, her talent sticking out only slightly. Ten years later, as an expert in eco-efficiency architecture, author of a popular book on eco-construction and designer of the first certified Passive House in the country, Mori sticks out enough to create new forms and lead Japan’s move into eco-architecture.

It wasn’t easy. Mori admits she was not even sure she wanted to go to a university: “I realized I was interested in creating shapes and drawing and sketching, making three-dimensional objects. I started preparing for art university, creating a portfolio, but all my designs kept getting bigger and bigger. Architecture is the biggest artwork, the most difficult sculpture to make.”

As Mori focused on architecture, she learned that her great-grandfather was a famous architect, designing the Presidential Office Building in Taipei in 1919 as well as other structures in Japan. “It suddenly became harder for me, the expectation that I had this talent in my blood, so I tried to keep a distance from my family until I studied about my great-grandfather at Yokohama National University.”

During her studies at the university, Mori became interested in so-called soft design architecture: “It was quite strange to me, why I needed a reason for a round shape in my design classes, but no reason or explanation if the design was square.”

Professor Kazuo Ishii at the university introduced Mori to the work of Frei Otto and his Institute for Lightweight Structures at the University of Stuttgart. Mori had finished her undergraduate work in 1999 and started on a master’s at Yokohama National University. She applied for and received a one-year scholarship to study in Stuttgart.

“After the year, I realized I wanted to study much more, so I decided not to go back to Yokohama. I switched my master’s to Stuttgart University. I interned in a design company, Mahler and Gunster and Fuchs (MGF Architekten) during the day, and studied in the evenings. It was very hard. I was handicapped with communication, and although I still felt like a student, I had a huge responsibility.”

This responsibility connected her back to Japan: MGF Architekten had won the right to design the German Embassy in Tokyo. As soon as she finished her internship and master’s, they hired her full time. Her hard work paid off — after five years in Germany she was fluent in the language, had obtained her master’s and learned valuable lessons in eco-architecture.

“Experience with energy efficiency is quite normal in Germany. Everyone has to be aware of it. I had to learn how to design a proper wall, I had to learn all the building physics — how to avoid condensation, how to conserve energy, why air-tightness is so important, all the things I did not know about architecture in Japan, because no one teaches it,” she said.

Still, Mori was not quite satisfied. Although she admits it was “good fun to pick out nice tiles from Italy or fancy, designer doorknobs,” Mori struggled with the limitation of working with only wealthy clients. “I decided what a private architectural firm can do is quite limited, because they have to make money.”

Mori wanted something different; she researched alternative possibilities, including working as an architect for the United Nations to develop housing for low-income people or temporary shelters.

First she had to learn one of the languages used at the U.N. Why? “Neither Japanese nor German are accepted since they both lost the war!” Mori laughs.

She sent out resumes to English-speaking architecture firms in London and Dublin and received a reply three days later.

Within two weeks she had moved from Germany to Dublin, and three weeks later, her life partner and fellow architect, Joerg Heil, joined her. He also found work quickly, and they each specialized in the knowledge of Germany’s eco-architecture.

“Ireland was not at the top of energy conservation like Germany, so they all wanted to learn this knowledge. We also had all the connections in Germany to consultants, so from that time on in Dublin, my focus became energy efficiency.”

Part of that focus led Mori to Passivhaus, or Passive House, a special certification in architecture that is awarded to projects that meet both exacting energy-conservation targets and low budget requirements. Passive House started in Darmstadt, Germany, when the first house was built in 1990.

“The original idea with Passive House Germany, 19 years ago, was that ‘eco’ shouldn’t be a luxury, it shouldn’t be voluntary, eco must be affordable and achievable for everyone.”

Using Passive House certification, Mori designed prototype special housing in Ireland, becoming an expert in the exacting demands of the Passive House Institute in order to meet the proper specifications.

As excited as she was by the experience and knowledge that was being gained in Ireland, Mori was nearing 32 years old — the age limit for applying to work at the United Nations. Still, life was full of meaning. Mori had married Heil and the couple had a young son. She made plans to write a book in Japanese and began design work on the first Passive House in Japan. After spending 10 years in Europe, Mori realized her nail stuck out pretty far.

“I started thinking, with all my experience, maybe I can bring something back to Japan, something completely missing in Japanese architecture: energy-conservation.”

With her knowledge from Germany and her experience with the success of the Passive House in Ireland, Mori felt she could bring something new to Japan. Although there are an estimated 15,000 certified Passive House buildings around the world, most of them are in Germany and Austria.

Mori also longed for home. “I was never escaping from Japan anyway, I always wanted to come back; I was lucky, too, because my husband had a positive impression of Japan, and he wanted to understand what I had been through, how I struggled as a foreigner living in Germany.”

Mori moved back to Japan in 2009 with her son, choosing to settle in Kamakura, Kanagawa Prefecture, because of its traditional architecture, greenery and slower pace of life.

Her husband remained in Dublin to provide income for the small family in case things did not work out in Japan. Only six months later, however, he was able to rejoin Mori in Kamakura. The Kamakura Passive House, and her book, were a resounding success.

“With the Kamakura house, I had to deal with new problems, the cooling and humidification, the termites, earthquake resistance, how the direction of the moisture changes from summer to winter; it became much more complicated than a Passive House in Europe, also difficult for the German side at the Institute, who cross-checked all my work to ensure we met their standards.” The house was completed in summer 2009, won Passive House Certification, and was followed by the publication of her book a month later, gaining her widespread attention among architects in Japan.

A year later, she is focused on education, mostly writing articles, meeting people and giving lectures and seminars to professionals.

In April, Mori started as a guest professor at Tohoku University of Art and Design. She is also doing consulting work for the next Passive House, which is to be built in Ibaraki Prefecture. In partnership with a small building company in Nara, Mori is developing a prototype house that she calls “a project to combine both minimum energy for running a house and minimum energy in the construction.”

As Mori explains, “We have such a great tradition in Japanese architecture. The energy spent for materials was zero, everything could be returned to nature, the soil, the bamboo, the wood and paper . . . but now if people from our generation move into those traditional houses, they put in an air conditioner or an oil heater. Our lifestyles have changed, so our houses must change as well. I want to transfer the traditional idea of a Japanese house into today’s energy-efficient house.”

Sometimes Mori feels she is fighting Japan’s conservative housing industry, where conventional wisdom states a home is no longer valuable after 30 years. “The trend now is to make a carbon-neutral house in Japan with the same basic envelope, flimsy thin walls, and add wind turbines or portable solar panels on the roof, or a highly efficient air conditioner or whatever. Yet after 30 years, none of the devices are working anymore and you don’t have any added value to the house itself, so it will just be demolished to start over; an endless cycle of waste.

“Yet, if the skin of the house is designed properly, the house will be durable for 100 years or more. Free from condensation, the temperature inside the house is stable without an air conditioner constantly blowing. We can live in this different way, and it is so important that a family can live without stress,” she said.

Mori’s face softens at the thought of her big ideas for Japan: “Maybe I will have to tell my students. In their 20s, a lot of young people stick out a little, but unfortunately, most of them get hammered down. In this society, no one will appreciate your small difference, so you must protect it, nourish it, find a way to let it grow — we need a new kind of education.”

For more information on Passive House and Mori, see and