The research about thatching and thatched roof

Master plans for cities and regions that coexist with nature

Coverage in the media(NHK WORLD CORE KYOTO)

NHK WORLD is the worldwide TV and radio programs by Japanese public broadcasting.

He was interviewed by one of their program for introducing core point of culture in Kyoto. He disseminated the wisdom of our ancestors’ traditions and the future possibilities of thatched roofs using scientific point of the research to the world.

・4th Feb 2021, Worldwide broadcast (approx. 1 billion viewers)
・1st Jul, 2021, Broadcast in Japan

Thatched roofs are not only for old houses

The essence of thatched roofs is a synthesis of the wisdom of our ancestors who have lived in harmony with nature for thousands of years, and is a synthesis of life, the universe, the earth, nature, people, architecture, cities, culture, history, the future, and the activities of all things in circulation.

It is the environment itself that supports the traditional and unique lifestyle and culture that has been updated in each era of the land. It includes the mountains, the forests, the rivers, the oceans, the sky, the fields, the rice paddies, the fields, the people’s livelihoods, the local economy, and everything in between. It is also connected to the universe. And together with the great cycle of nature from the forest to the sea, it has fostered a beautiful landscape.

Climate change, environmental problems, infectious diseases, local issues, the cacophony of the nation and the world, there are so many problems in this day and age, but by scientifically reevaluating thatched roofing and the traditional wisdom associated with it, applying it to the modern age, and developing and designing models that can be applied in the future, we can solve these problems and create a happy and prosperous society.

We will do this in the fields of architecture, urban design, landscape architecture, land planning, and environmental design.

Modern Use of Thatch to Save the World

For example, think about covering the exterior walls and glass of the modern concrete buildings that make up most of today’s cities with thatch called “Toma”. By doing so, solar radiation will be blocked, insulation will be improved, and energy consumption for heating and cooling will be reduced. It will also prevent the deterioration of concrete, finishing materials, and glass. Toma can be renewed in a few years and used as fertilizer for the fields.

Thatch can also be used for interior materials and insulation. Recent studies on the microbial environment of thatched roofs have shown that the microbial environment inside a thatched roof is almost the same inside and outside the house, and no pathogenic bacteria have been found. In ordinary houses, the microbial environment inside the house is human-derived, while the environment outside is naturally natural-derived, and many pathogenic bacteria, including those in the water area, grow there. In recent years, we have come to know more about intestinal bacteria, and it is important to improve the microbial environment in buildings and cities as a whole in order to maintain the physical and mental health of people, including the new COVID-19. The materials used are thatch and rice straw, which are widely available in the country side called “SATOYAMA”, now world wide word from Japanese. It is possible to create a cycle of production (thatch grows even if left alone), harvesting, utilization, and fertilization, and it can also contribute to carbon dioxide absorption (as a C4 plant, it can photosynthesize more actively in a hot and dry environment than in a normal forest) and carbon fixation.

This is just one example, but there are many modern uses for thatched roofs and the traditional wisdom associated with them. Measures against infectious diseases, measures against global warming, measures against cold weather, measures against extreme weather, regeneration of the natural cycle, environmental regeneration, promotion of people’s mental and physical health, creation of a healthy environment for childbirth and childrearing, protection against electromagnetic waves, creation of a healthy body free of allergies, use in space architecture, highly efficient biomass energy, building materials that return to nature in the end. Creating beautiful local cultures and landscapes, creating rich relationships between people, and stimulating local, national, and global economies.

The scenery of making Toma. Toma can protect the architecture softly and flexibly

An experiment in which tiles are covered with Toma

Thatched Architecture in Africa by Professor Toshiko Mori, Harvard University

Thatched Architecture in Africa by Professor Toshiko Mori, Harvard University
Thatched Architecture in Africa by Professor Toshiko Mori, Harvard University

Beautiful landscape in Yamaguni area in Kyoto

“Kaya-hoko” in the winter season after harvesting thatch

Fumikazu Nishiyama

He studied architecture and urbanism at Miyagi National College of Technology, University of Tokyo, and Technical University of Munich.
His ancestors have been involved in priestly and metropolitan construction, which has served as a link between nature and people.
He has been involved in architectural design and consulting, archaeological survey work, overseas real estate development and investment, the launch of overseas business for a resort sports brand, and project management for a fusion energy research and development project called “ITER”, the world’s largest project since the beginning of time, involving more than 30 countries. Since his student days, he has been researching and designing space architecture and future architecture and cities, and finally arrived at thatched roofs, which have created a society where nature and people are in harmony. Currently, he is promoting the modern use of thatched roofs while conducting research in Keihoku. The town is another Kyoto where had built and supported old capital in Japan called “Heian-kyo”, which planned by one of his ancestors, presently we know as Kyoto.


Yamaguni is located at the headwaters of the Katsura River, and in 784, Emperor Kanmu ordered 36 officials to be dispatched to build Heian-kyo. Until the Meiji era (1868-1912), the area was the site of the imperial palace, and built the residence of the nobility, and shrines and temples by wood materials from this area. In addition, materials of buildings for the most important ceremony in Japan called “Daijo-sai” and the Imperial throne are also from Yamaguni area. The area has a long history of offering sweetfish to the emperor and the capital, and can be said to have served the emperor well. At the end of the Edo period (1603-1868), the Yamaguni-tai, a group of peasant soldiers, fought bravely in the Boshin War and were at the forefront of “Jidai-matsuri” festivals. In recent years, however, the forestry industry, the main industry of the region, has been slowing down due to the decline in lumber prices, and the population has declined from 10,000 to about 4,500. However, the number of immigrants who are attracted by the natural beauty of the area is beginning to increase.


Master plans for cities and regions that coexist with nature

In the same way that thatched roofs have connected the universe, the earth, people, life, nature, the central and the local, and the world and the local, through research and development, design, and manufacturing, we aim to create a sustainable society in which people, nature, and the local community can continue a virtuous cycle in a better balance while solving local and global problems. In the past, since the Jomon period, Japan’s satoyama and cities have been intertwined with each other to create one big circulatory system that includes human life, spirituality, cultural activities, resource circulation, ecosystem, natural circulation from forest to sea, and landscape. By learning from the past and applying it to modern society, Japan can take a leadership role in solving the world’s problems.
To this end, we will bring together the wisdom and technology of our predecessors and modern experts in various fields, consider what is essentially needed for society, people, and the global environment for future generations, and give form to it with hardware and software.

Contribution to circulation and the environment

Thatch is friendly to people and nature, and is the best cyclical material that can be used for roofing and interior materials.

Japanese pampas grass and reeds (carbon dioxide absorption, carbon fixation, purification of soil, water and air quality, prevention of landslides)

Used also as insulation of buildings and snow fence in the winter season.

Withstands wind and snow as roofing material, heat insulation effect, carbon fixation.

Old thatch taken down from the roof (for a beetle nest).

Turning old thatch into fertilizer for rice fields.

For delicious, safe and secure rice and vegetable.

rice straw.

Utilization of rice straw (earthen walls, shimenawa, rope work, etc.).

Features of thatched roofs (examples)

As architecture and scenery
・The original landscape of Japan, a landscape of healing
・One of the original forms of human dwellings, found all over the world
・A forest-like roof that nurtures all kinds of living things such as insects, birds, and plants (moss, trees, grass)
・A shelter that protects the inside from rain, wind, electromagnetic waves, sunlight, etc. (used not only for houses, but also for shrines and the Daiichigu, the building that is used for the most important ceremony in Japan)
・A space where you feel safe as if you were in your mother’s womb (lightly dark, quiet even in the rain, warmth, smell of nature…)
・Flexible response to environmental changes
・Dismantling, relocation, conversion, extension, and reduction are flexible.
・Flexible structure that can withstand earthquakes and typhoons.
・Use of local resources and construction that ultimately returns to the earth

The function of old thatch

・ Thatch taken down from the roof is to provide fertilizer for the fields (a valuable source of fertilizer in the past).
・Nests for beetles and other insects
・Soil improvement materials for environmental regeneration

Things that lead to human health
・An essential way of life for people with natural fire (irori, kamado)
・Cool in summer and warm in winter
・Good sleep
・No pathogenic bacteria found, microbial environment is almost the same inside and outside the house
・Possibility of urban design (The shape of architecture and lifestyles evolved in the Nara and Heian eras in order to live in harmony with the plague.)
・Fermented foods are often produced in the house
・The sterilizing, disinfecting, and longevity-enhancing effects of the wood vinegar solution in the hearth.
The sterilizing, disinfecting, and long-lasting effects of wood vinegar solution in the hearth

Things that lead to environmental regeneration and natural cycle regeneration
・Acts as an environmental regeneration device by improving underground water veins and air flow
・Ecosystem of Kayaba, thatch field nurtures all kinds of living things
・Natural circulation from the forest to the sea created by forests and thatch grounds, and prevention of landslides and animal damage
・Prevention of landslides and animal damage
・Thatch as C4 plant that activates photosynthesis even in hot and dry environments. Common plants as C3 plants. In hot and dry environments, respiration is more dominant than photosynthesis.
・Perennial (can be harvested once a year, high productivity)
・The roots purify soil, groundwater, lakes and rivers.
・Stems and leaves purify the air.

Thatched roof and thatched architecture in outside of Japan and modern usage of thatch in Japan

England    Polinesian countries Germany(Built over 350 years ago)
      Modern thatched architecture in Denmark       Modern thatched architecture in Netherland
Modern thatched house in Netherland         Modern thatched architecture in Netherland
Modern thatched usage in beauty salon and shrine in Japan (By thatcher Sagara)

Thatched roofs have existed since ancient times not only in Japan but all over the world. For example, in Southeast Asia and Polynesia, palm leaves and banana leaves have been used for roofing, while in Europe, wheat straw and reeds have been used for roofing. In the Netherlands, thatched roofs have been used for the walls of water mills, and even today, new forms of modern architecture are being proposed, not only for roofs but also for walls and interiors.
In Europe, new possibilities for thatched roofs are being explored, and thatched roofs and walls are becoming an option for citizens in housing complexes and general housing, and have become a major industry.

Architecture and cities that return to the earth

When the capital was moved to Heijo-kyo from Fujiwara-kyo in the early 8th century, almost all of the buildings were dismantled and relocated, but the modern concrete buildings cannot be done like that. It can be understood as the advanced form of architecture and city.

Modern architecture and cities
・Manufactured by machines using a great deal of energy.
・Life expectancy is several decades.
・Dismantling, relocation, and conversion are basically unthinkable.
・Dismantled with a lot of energy.
・Closed cycle or waste that does not return to nature.
・Ends up destroying nature.

Traditional architecture and cities
・Consists of buildings made of natural materials.
・Many of them are made by human hands in a traditional way without using much energy.
・Many of them are built by hand with little energy.
・Life span of several hundred to more than one thousand years
・Easy to dismantle, relocate, and convert
・Easy to dismantle, relocate, and convert to other uses
・Return to nature as fertilizer or fuel

Architecture and cities in harmony with microorganisms

Most modern cities are built with artificially processed materials such as steel, concrete, glass, and chemical products.
On the other hand, traditional architecture is made of natural materials such as wood, earth, and thatch.
The VOVID-19 can survive for several hours in the air and two to three days on solid surfaces, according to a study by the Centers for Disease Control and Prevention (CDC) and a team of researchers from the University of California, Los Angeles (UCLA) and Princeton University.
On the other hand, viruses have many enemies and cannot survive for a long time in soil with a wide variety of microorganisms (“Topsoil and Viruses” by Masatoshi Funabashi, Researcher, Sony Computer Science Laboratories)

The COVID-19 can be an opportunity to rethink the way of architecture.
Similarity has been done since ancient times. Using a lot of natural materials and coexistence and co-prosperity with all kinds of microbial environment will lead to human being to be alive. Our ancestors may have understood this.

Epidemics and Architectural Changes
・The impact of epidemics such as smallpox in the between 8th and 10th century on architecture
・The pit dwelling was replaced by a structure with walls and doors, a fire in the hearth, and 24-hour ventilation
・Large ventilation openings (gables)
・Fires in the hearth sterilized and disinfected the droplets, which were then released by an updraft
・Possibility that the transition from epidemic to endemic gradually led to a loss of understanding of the causes and reasons for this cultural change

Hypersonic sound

High frequency is the range of sound that exceeds the human audible range (up to around 20,000 Hz for people with good hearing) and called as “hypersonic sound”.
This hypersonic sound is received through the skin, and is effective in improving immunity, reducing stress, and fostering sensitivity to the beauty of things.
Dr. Tsutomu Ohashi, Professor Emeritus of Tsukuba University, and Dr. Manabu Honda of the National Institute of Neuroscience, National Center of Neurology and Psychiatry, are conducting research on this topic.

Fumikazu Nishiyama has researched this hypersonic sound environment in keihoku and Miyama where we can see Japanese traditional life style still now with much of nature and thatched houses and found out that there are much of hypersonic sound environment there.

      sound collector(made in Sweden)        sound measurment by smart phone with special app
sound collecting in Keihoku where we can see Japanese traditional landscape and life style
irrigation channel … around 100000 Hz the sound of kicking dry grass … around 140000 Hz
spring water … around 80000 Hz small stream of the river … around 100000 Hz
 harvesting the thatch in December 2020 in Miyama and it was the highest record over 180000 Hz among
Keihoku and Miyama investigation

Umi Yama Aida, a film about Japanese traditional sustainability

Japanese Traditional sustainability in shrine
Ise Jingu Shrine is one of the most important shrine in Japan. It conveys the sustainable architecture, environment creation, and spiritual culture creation that the Japanese people have continued. By planting a well-balanced mix of coniferous and broad-leaved trees, animals eat the fruits of the broad-leaved trees, microorganisms decompose their excretions to form humus, rain falls on the rich soil, which becomes nutrient-rich groundwater, which gradually flows into rivers and eventually reaches the sea, where phytoplankton grows and fish, abalone,
and oysters grow well. Nurturing the forest eventually comes back to human activities. Large diameter trees grown in the forest are used as building materials and are treated with care until the very end. In the forest, there is a great orchestra of minuscule sounds that are inaudible to the human ear but certainly exist, such as insects, animals, the murmur of the river, and the sound of trees and leaves being tossed by the wind.

Our ancestors, who were mammals, lived in the forest from time immemorial, but moved to the plains with the agricultural revolution about 10,000 years ago. For this reason, we still feel refreshed when we enter a forest because our genes evolved in such an environment.
In comparison, in modern urban environments, there are too few mediums that emit hypersonic sound. Construction sites and transportation systems are filled with unpleasant noise. Traditional farming tools (sickle, hoe, thresher, mortar, etc.), construction tools (saw, planer, chisel, etc.), and musical instruments (shakuhachi, oboe, etc.) also emit hypersonic sound.
Modern life is a stressful society, and many infectious and new diseases, including COVID-19, are still a problem. The problem is that there is far less environmental information available to boost immunity in urban areas compared to the environment our ancestors once lived in.

Thatched microbial environments that create health

The bacteria from the thatch, and the microbial environment indigenous to thatched old houses contribute to health.
Bacillus natto (fermented soybeans) is produced from rice straw, which is a member of the grass family, and the bacteria boosts the immune system. In the same way, there is a possibility that some kind of bacteria is produced from the grass plant, thatch, and has the effect of raising intestinal bacteria and increasing immunity. Residents living on thatched roofs are inoculated with bacteria from the thatch in their attics as they breathe, and in houses that use old thatch as fertilizer, bacteria from the thatch enter the crops and are inoculated by eating the crops (according to testimony from residents of thatched roofs, crops fertilized with thatch become crops that match the physical condition of the person who grew them). Inoculation by eating thatched-roof crops. Many elderly people living on thatched roofs have longer and healthier lifespans than those living in ordinary house-buildings or concrete apartment buildings (testimony from thatched roof workers and residents).
Hundreds of trillions of bacteria are indigenous to the human body. About 90% of them are found in the intestines. About 70% of the human immune system is based on intestinal bacteria.

Influence of intestinal bacteria
・Increase immunity
・Prevention of adult diseases (obesity, diabetes, etc.)
・Mental and emotional behavior
・Brain activity, learning function, etc.

Research with Kyoto University and Hiroshima University revealed that the microbial environment inside an old thatched house was almost the same inside and outside the house, and that no pathogenic bacteria were found.

Coverage in the media(NHK WORLD CORE KYOTO)

NHK WORLD is the worldwide TV and radio programs by Japanese public broadcasting.

He was interviewed by one of their program for introducing core point of culture in Kyoto. He disseminated the wisdom of our ancestors’ traditions and the future possibilities of thatched roofs using scientific point of the research to the world.

・4th Feb 2021, Worldwide broadcast (approx. 1 billion viewers)
・1st Jul, 2021, Broadcast in Japan

Comments from overseas
・I would like to know the secret of thatched roofs as a result of the research on thatch fungus.
・The tradition of thatched roof replacement is worthy of praise.
As shown in this program, I think that the empirical knowledge built and passed down by the ancestors of all civilizations around the world needs to be scientifically scrutinized and its benefits documented.
・I thought it was just about forests and forestry, but it was interesting to see the story unfold from a different angle. I became interested in thatched roofs and traditional Japanese houses.
・It was wonderful to learn about the traditional lifestyle of Mr. Shigeri Kawarabayashi.
・I would like to know more about thatched roofs in a longer program next time.
・All the sections were good, but what impressed me the most was the story of two researchers who wanted to learn from tradition and use it to improve the modern world.
・I was very much fascinated by the contribution of thatched roofs to health, and learned a lot from this program.
・I thought that what I learned in this program is very important for the current and future generations.
・It was very impressive to learn how Japanese people still value nature and are connected to it.
・I am looking forward to the next one.
・People in Kyoto believe that thatched roofs are good for their health, and I think it is true because thatched roofs are made of natural materials.
・The “sustainable lifestyle” section sends a strong message about how important thatched roofs are.
・Thatched roofs hold the secret to a long and healthy life.
・This program has given me a better understanding of the ancient Japanese capital.

Research on new high-performance building materials using thatch

Durable, waterproof, and fire retardant material that can be used as fertilizer after disposal

Problems with modern building materials
Many of the building materials used today are chemical materials, which are rarely reused and do not return to nature after disposal. The act of construction often implies the destruction of nature, massive consumption of resources and energy, and irreversible use.
In order to create a truly sustainable society, we need to improve the building and construction industry, which accounts for about half of the energy consumed in the world, requires the largest volume of materials, and creates the largest amount of waste, and we need to innovate to make these materials less harmful to nature. If this can be achieved, the social and economic impact will be huge.

Functions of thatch
・Strong and light due to the presence of silicon
・Used as fertilizer for fields after disposal
・Absorbs carbon dioxide (carbon-negative)
・Purification of radioactive materials
・Air purification effect
・Heat insulation performance (equivalent to glass wool at about 1.2 times the thickness)
・It has been used since ancient times to create sacred spaces that need to be cleansed, such as the Daijo-sai, Ise Shrine, other shrines, and the wheel of thatching (shuts out electromagnetic waves, rain, wind, dust, etc.)

Thatch has the above effects, and the fibers are extracted from this thatch and processed into membranes to be used as building materials. We will develop a new material that has both heat insulation performance, air purification effect, moderate translucency, and heat shielding properties.

Assumed applications
Building envelope and roofing materials, glass substitutes, membrane materials, clothing, etc.