Case studies - Japan

part III case studies

A study of Japanese wooden architecture

Kunnskapsemne AAR4900

Jenny Fausa Torvik and SIgrid Lyche Strandvoll

Norwegian University of Science and Technology, fall semester 2022

Farmhouse of the Tsunashima Family

綱島家の農家

Farmhouse of the Tsunashima Family

Name: Farmhouse of the Tsunashima Family

Architect: Unknown

Location: Edo-Tokyo Open Air architectural Museum

Original location: 3-chome, Okamoto, Setagaya Ward

Built: Mid-Edo period (1603 - 1867)

Program: Farmhouse, residential

Category: Reconstructed Building

View towards the wooden and tatami matted floors.

Intro

The Tsunashima Family house from the Edo-period is a representative example of traditional Japanese Minka, meaning the traditional houses of rural Japan. Originally it was located on a plateau overlooking the Tama river, in the area that is today known as the metropolitan area of Tokyo. The house was passed on through ten generations, and the family cultivated grain and vegetables. Today, the farmhouse has been reconstructed in the Edo-Tokyo Open Air Architectural Museum in Tokyo. We visited the farmhouse while spending a day at the museum on the second day of our study trip, which was a great introduction to the beauty and sensibility of traditional Japanese architecture. Our fascination for the farmhouse grew rapidly as we moved around and through the structure, discovering the different aspects of the architecture.

Due to the topography of the Japanese archipelago, stretching all the way from the far north to the south, Japan’s Minkas are as diverse as its climates and landscapes. The Farmhouse of the Tsunashima Family were originally located in central Japan, where the climate was hot during the summers but where they also faced cold winters with snow. Here, Minka would typically be large

multifunction structures, spacious enough to accommodate both living and work under the grand, thatched roof. The Farmhouse of the Tsunashima family is divided into two zones; the large earth-floored work area known as doma, a continuation of the outside level, and the raised floor zone covered with wooden boards and tatami mats for living. Footwear is removed when entering the raised part, in accordance with ancient custom. On the doma all sorts of farmwork and handicrafts could be carried out during the cold winter months, it could even house the farm’s livestock. It is said that this northern current of the minka tradition draws from the Japanese pit dwellings of pre-historic times called tateana, and that these again were heavily influenced by the culture of northeast Asia.

In this case study we will focus on the farmhouse typology, the construction, the thatched roof, and the use of locally available natural materials. In addition to being an interesting wooden structure to study, we think the farmhouse is a good representation of the aesthetics of rural, traditional Japanese architecture. We believe that the quote on the following page describes quite nicely why we find the minkas so fascinating, beautiful and important to study in our time.

“Roofs were thatched with reeds or tall grass cut from communal meadows, and walls were plastered with earth from nearby hills. These natural materials gave minka a natural, unpretentious beauty. Their charm is robust, unprepossessing, and above all functional. Age becomes a minka; its beauty is only enhanced by the patina of time and continuous habitation.” 1

Kawashima, 1986

View towards the south side.

The plan of the minka typology

The plan shows the dynamic relationship between the earth floored zone for work and the wooden, lifted one for living. The centrally placed rectangular posts represents the division between the two zones, the most central one being the sacret daikokubashira. All areas of the structure offers great flexibility and functionality to the different activites needed to be carried out throughout the day.

The rooms of the living part shows the floating relationships between the different rooms, which is characteristic of traditional Japanese architecture. They are arranged

into what is generally known as the “hall style” interior. With classical features like tatami mats, the shoji sliding elements and the sensitive framing of views towards the surrounding landscapes, the farmhouse gives insight to important values and traditions of the Japanese culture.

We are especially fascinated with the duality of the typology’s program; the fact that all activities of both family life and work can be carried out under this very roof. In addition, the transition in the plan between the very elegant formal rooms in combination with the rough working zones is quite remarkable.

The sunken hearth and doma area.

doma/ earth floored area

main entrance

daikokubashira/ central post w. sacred significance

idoko/ living room w. sunken hearth

nando/ bed room and clothes

hiroma/ lit. “big room”; a large family room

zashiki/ formal room zashiki/ formal room

Construction

The Farmhouse of the Tsunashima family is built on the Japanese tradition of wooden joinery without the use of metal nails. The structure is a wooden framework, consisting of posts, beams and roof trusses. We assume the construction is a version of the wagoyagumi beam system, also called the “Japanese

extended and works as climatic protection for the wooden panels and clay walls. The fundament of the building is ishiba-date, litterally meaning “standing on the stones”, in which each post is resting on a separate foundation stone. Traditionally, this is the most common fundament technique in Japan. However, in today’s building practice it rarely occurs beacuse of building regulations preventing it.

It is important to state that our descriptions and drawings of the framhouse construction are assumptions based on theory books, consultations with our professors and evaluating photos. In other words, our interpretations might be incorrect. Nevertheless, we believe they form a representative theory base for learning about these types of farmhouse buildings.

Structure reference: The beam system Wagoya-gumi

Inside the farmhouse.

Outside the farmhouse.

Orioki-gumi detail

The detail of the relationship between the transverse beam to the eave purlin and post is called orioki-gumi. A tenon on the top of the post connects it to the transverse beam and then the eave purlin (see figure).

The nail-free joinery allows for lateral movement, which is positive considering earthquakes. On the contrary, it does not secure it in the vertical direction, which

might lead to dislocation of the building elements during the vertical movement of eartchquakes. This is the reason why building regulations in Japan today requires steel angles in similar building details, in order to prevent this dislocation.

Detail sketch of the relationship of transverse beam to eave purlin and post: Orioki-gumi

ridgepole

reed screen

reed (yoshi)

hoko-dake and komai-dake tied tohether with cord

rafter (taruki-dake)

roof purlin (yanaka-dake)

brace (sasu)

transverse beam

eave purlin (noki-geta)

eave-end support (kaya-uke)

suspending cord (tsuri-nawa)

the villages. Thatched roofs have a limited durability and must be rethatched regularly, typically every 15th year. Despite the disadvantage of the short durability and the fact that they are susceptible to fire, these roofs have many advantages. They are lightweight, they insulate the house against heat in summer and cold in winter, they work as good sound insulation and above all, they’re extremely environmentally friendly as they are based on a locally available, biobased natural material.

are dried stems of so-called true grasses.

Noshi-buki is the name of the construction method used in this rood, where bundles of reeds are laid in two or more tiers with an exposure of generally 90 centimeters. When thatching, the root end of the reed is usually laid toward the eaves and the leaf end toward the ridge. The process starts in the eave end, securing the bundles by tying knots of cord.

Principal detail sketch: The structure of a thatched roof

post

Thatched roof

The eaves of the thatched roof meets the main construction

東大寺 南門

Todai-ji South Gate

Founder: Emperor Shomi

Location: Nara

Built: 738

Program: Main portal to temple complex

Category: Traditional, religious structure

Focus: Structure, details, design method

The structure seen from underneath.

Located in the important cultural city of Nara in central Japan lies the great Todai-ji. The temple complex consists of several buildings and it is listed a UNESCO World Hertage Site as one of the “Historic Monuments of Ancient Nara”. Along with the introduction of Buddhism from China in Japan in the 6th century CE came also new architectural influences from the continent. Not only did it influence the religious architecture, it also came to have great impact of the development of Japanese wooden architecture in general.

A visit to the Todai-ji temple was already planned ahead of our study trip, but our interest in the gate grew when we visited the office of FT Architects in Tokyo. When we talked to them about their wooden Boxing Hall designed in 2013, they explained to us that they used the structural principle of the bracket system in the South Gate as their main reference. By studying the old structure, they wanted to make a new interpretation.

With 35 degrees and extremely high humidity, loads of Japanese school children and the wild deers of Nara Park circling around us, our visit to the Todai-ji was an experience out of the ordinary. As we approched the South Gate we were both surprised and impressed by its enormous scale. Ranging almost 30 meters up in the air, it is definitely a powerful and strong marking of the ritual of entering the temple complex.

Japanese temple architecture represents a very interesting duality. One one hand, the influence of spiritual and religious beliefs manifests itself in the physical structure and form. On the other hand, the structure and detailing is of very rational character.

Our focus in this case study is understanding the load bearing system, the structural details and studying the method of FT Architects when designing their Boxing Hall.

Structural system

The South Gate wooden construction consists of large posts and beams, with two levels of protudings eaves. These eaves are typical for the Japanese temple- and shrine architecture, being both decorative and functional in terms of protecting the main structure from rain.

The construction system used for supporting the grand eaves is called tokyō, and is a more refined version of the Chinese dougong. The system consists of supporting bracket arms, hijiki, and weight bearing blocks, masu. Brackets in contstruction can be defined as elements that projects from the posts to carry the weight from above. The simplest configuration of the tokyō system would be a single projecting bracket and a single block.

But the greater the eaves extend and thereby the more load that needs to be carried, the more complex is the tokyō required to be. As we can read from the section, each eave in the South Port is carried by six levels of bracketing.

The system is less efficient compared to typical western construction systems where the load would be carried by one diagonal element. However, systems consisting of only vertical and horisontal elements is more resistant to earthquakes as it has more inherent elasticity. Each element can absorb energy and will therefore work as shock absorbers.

Conceptual detail of bracket-block-joinery

Pretruding eaves of the roof.

The bracketing system.

Learning from FT Architects

The Tokyo-based architectural office FT architects used the bracketing system of the Todai-ji South Gate as their main reference in their acknowledged Boxing Hall. The project consists of the boxing club and an archery hall, standing a few hundred meters apart on the grounds of Kogakuin University in west Tokyo.

The boxing hall needed to be a column-free space of 7,2 m by 10,8 m, and the University wanted two low-cost structures made of locally sourced timber. FT Architects also decided to work with timber members that were deemed defected because of insect damage and therefore short in dimension. These starting conditions demanded for FT architects to come up with an innovative timber solution.

In conversation with Katsuya Fukushima, one of the founding partners of FT architects, in

their office in Tokyo, we were quite fascinated with their process of designing the hall. Katsuya San stressed the importance of really deriving and understanding old structures when using them as inspiration, instead of simply immitating them in a romanticising way. With this as their ideology, FT Architects studied the tokyō system and interpreted it into solving their design task of structural and spatial solutions. The boxing club was constructed using bolt-and-nut assembly. In the sketch below, we can clearly see the similarities between the structure of the South Gate and the boxing club based on bracket and block elements.

We believe the project forms a very good example of how we can learn from traditional wooden structures and then consciously interpret the wisdom of tradition into the architecture we design today.

Conceptual construction sketch of Todai-ji south gate to the left and Boxing Hall to the right.

“We have salvaged the purity of traditional Japanese timber composition, simply made up of horizontals and verticals, which has been somewhat disregarded ever since the advent of modernism in Japan. A bolder, stepped frame, was employed for the boxing club.” 2

Figure 1: Construction system. Figure 2: The boxing hall space

FT Architects

Kawasaki Pottery Shop

川崎陶器店

川崎陶器店

Kawasaki Pottery Shop

Architect/carpenter: Kyo Machia

Location: Kyoto, Japan

Built: Around 1900

Program: Pottery warehouse

Category: Old wooden structure

The pottery in the shop.

The day we planned to spend some time off in Kyoto we decided to explore the district close to our guesthouse. The neighborhood we lived in was called “the pottery district”, and so was our mission to find some kyo-yati - fine pottery of Kyoto.

In the beginning of the Momoyama period (1568-1600), artisans and techniques from the whole nation were gathered around Kyoto, which was the capital at that time. Many workshops developed as the tea ceremony was to become a beloved ritual, and the craftsmanship of ceramics produced some of the most sophisticated tableware you can find.

While walking through the pottery district we stumbled upon a wooden warehouse which one could sense was extra special. Toutensei Kawasaki is a 8th generation pottery shop in the KiyoGojo area.

The townhouse was built by Kawasaki-San’s own grandfather, Kyo Machia, 120 years ago. Kawasaki-San himself, was born in this house

and lived there with his parents, uncles, aunts, siblings and cousins. He even pointed out the place he was born: on a tatami mat with a view to a Japanese garden. Since then the family moved out and now hosts a store with storage.

The next day we decided to go back to ask Kawasaki-San more questions about the building and make some measurements, which we were more than welcome to do. Kawasaki-San had a lot of knowledge about the wooden house and was eager to pass on the knowledge to us. It was clear that Kawasaki had great interest in maintaining the house properly and that he wanted to use as much natural, non-chemical materials as possible when doing so.

In this case study we want to focus on this use of natural, biomass materials and their properties, and low tech solutions for ventilation and light. As the house sits in an urban, dense context, we will also have a look at the Kyoto city plan.

“We Japanese love nature. It’s good to have a relationship with nature. Everyday in the city, cars are rushing by. But in this direction when I see the garden I feel calm. I feel very good. Some birds come by, sometimes butterflies too, and also frogs and small insects. The garden teaches me many things. One of them is when I see that the garden is beautiful, my heart is also beautiful.. The garden teaches me how my heart is. And, facing the garden, I can think about how I should behave, how I should work, how everything should be. It’s like meditation.”

Toutensei Kawasaki

Full interview with Kawasaki-San

S Do you live here, is this building also your house?

K I was born here on this Tatami mat many years ago. This house is renovated as a warehouse, but originally this was an Udon house. At that time, my aunt and uncle and their many children lived here. We were a big family. Kyoto used to have a big population, but now it’s decreasing. But before, there were many children and many families in every house.

S We noticed the clay floor, how was it made?

K Similar to the walls, the floors are made of clay, cutted straw and salt. If there was only clay, it would crack when it dries. So the cut straw binds it together. To make it compact, you ram it. This clay floor is called ‘Tataki’ which means ‘to hit’.

S Is there any coating on top?

K My wife and I painted a little coat, a binder, so it won’t be gradually damaged by shoes.

This is the only chemical I used in the shop and it’s not traditional. I’m sorry that I had to use this chemical. There’s also salt in the mixture. Did you see the small playing ground on Saku? They threw salt before fighting. It means two things: for the religious meaning: to purify the ground. And the physical meaning: salt hardened the surface of the clay playground.

S What do you put on the wooden material?

K Iron, carbon black, oil and fermented persimmon. The persimmon protects it from worms and white ants because they eat wood. It also protects from water. First, mix iron and carbon until it’s black and then use the persimmon paint. And in the end you use the oil. I think it’s a good process. Inside, we usually paint once every third to fourth year. Outside, we should paint once a year because of the rain, wind and dust which is very harmful for the wood.

S How does the ventilation work?

K After a hot day in the evening when the sun

Toutensei Kawasaki

is down, we splash cold water in front of the house. Immediately the water gets hot and flows upwards. And then, the cool air from the japanese garden flows through the house because of the low pressure created in front.

J Do you have other methods for ventilation?

K For example, there is a gate underneath the floor (points underneath the tatami flooring in the shop). So under this gate cool air comes up from the ground.

S You said that the Japanese garden’s intention is for example for ventilation, but is it also a ritual space? What is the main reason for having garden in the atrium?

K Ah, the atrium. We Japanese love nature. So,

the garden has trees, small water basins and small fishes. It’s good to have a relationship with nature. Everyday in the city, cars are going so fast. Rushing by. But in this direction when I see the garden, I feel calm. I feel very good.

Some birds come by, sometimes butterflies too, and also frogs and small insects. The garden teaches me many things. One of them is when I see that the garden is beautiful, my heart is beautiful at the same time. The garden teaches me how my heart is.

And, facing the garden, I can think about how I should behave, how I should work, how everything should be. It’s like meditation.

Material pallette

Treated outside panel with patina.

Shoji: movable screens changing from straws in summer season to paper in winter season.

Stepping stone with a water basin in the Japanese garden.

Paper sliding windows and exhibited ceramics.

The pottery shop seen from the tatami room on the first floor.

Indoor stepping fundament, wooden step and tatami mat on uplifted floor level.

Construction

As mentioned, the Kawasaki pottery shop is a wooden post and beam construction built on traditional principles. Unlike the traditional European wooden construction, diagonals are rarely used to gain stiffness. Instead, beams were attached to posts through a variety of joints depending on its placement in the building. The intersections had to be firmly fixed to resist natural caused disasters such as strong winds from typhoons or earthquakes.

The walls consist of a base frame (sjitaji) of bamboo laths suspended between posts and covered with clay, leaving the posts and beams visible in the interior and exterior. The laths are reinforced by poles of unsplit young bamboo or thicker bamboo laths.

This bamboo framework is laced together with fine straw cord. When the base frame is complete, a layer of fermented clay mixed with chopped rice straws (works as a binder) is plastered on the outer side and smoothed over while still damp.

The mixture is normally fermented from a few days until three months and in some cases even uptil years to strengthen the wall’s quality. It also increases its workability in plastering. When this layer has dried, the other side is plastered. If it’s not meant as a “rough wall” you apply a second and third layer on each side, which is the middle coat and a finishing coat. This way of constructing a wall is referred to as building “a hanging wall”.

Post and beam construction seen from the gallery on the second floor.

Finishing coats for clay walls

While going through the house, we noticed that the walls had some different characteristics and finishing coats. Depending on the usage, the clay mix has added materials to gain different abilities. For example for different hardness, color, texture, reinforcement and so on.

“One of these coating methods is called ‘shikkui’. Shikkui is an ecological nontoxic Japanese lime plaster primarily made out of hydrated lime and calcium carbonate coming from reprocessed eggshells. The coatings are porous and antiseptic (preventing the growth of disease-causing microorganisms) and are therefore good for indoor air quality. It’s also said to be humidity-regulating, fire-resistant, antistatic (preventing dust accumulation), hypoallergenic, antifungal and mold resistant”. 3

Another common material is seaweed glue used as a component to retain moisture and improve workability. It’s also possible to add iron flakes and fragments, to create an earthen finish speckled with rust.

In addition to having a low carbon footprint and energy consumption in production, these methods contain materials that are fully recyclable and compostable.

Fermented mudwall coating from the interior.

Shikkui wall.

Layers in a clay wall with bamboo lattice.

The Kyoto Plan

Kyoto, officially Kyoto City in Kyoto Prefecture, is considered to be the ‘cultural capital’ of Japan. It was chosen as the new seat for Japan’s imperial court by Emperor Kanmu and was then moved from Nara in 794. It is also known under the name ‘the Heian Capital’ (referring to the historic period) or ‘Miyako’ (meaning ‘the Capital’). It wasn’t referred to as Kyoto (meaning the western Capital) until the capital was moved over again, when the Edo period started in 1870, to Tokyo (meaning the eastern Capital).

“The new city was laid out as on the same plan as Nara, with the ‘Shujaku highway’ down the centre dividing it into left and rigth capitals. The city plan contains nine avenues. ‘The Shujaku highway’ also referred to as ‘The Great Highway’ was 280 feet wide and the other avenues were 80 feet wide, with exceptions which were 170, 120 or 100 feet wide. Similarly in the transverse streets running parallel with the Shujaku, those at the extremeties, the east and west ‘Kyogoku’, and two other were 120 and the rest 80 feet wide. The smaller lanes were 40 feet wide. The city unit has a block of 400 feet square called a ‘cho’, which was normally divided into thirty-two residental areas of 50 by 100 feet. The whole city was surrounded by an embankment and ditch and was intersected in both the south-north axis and east-west axis by continious main streets to make flow.” 4

This leaves the impression of Kyoto as a city with a rather strict city plan where it is easy to navigate. The order of the square blocks makes the townhouse typology the natural choise for residental houses. In this typology, you are left with a narrow facade which makes it necessary to have certain strategies to contain daylight and ventilation.

In the city plan to the left there are deposited areas for certain institutions. They are as follows: (A) Imperial City. (B) Palace. (C) Horaku-in. (D) Hassho-in. (E) University. (F) Shinsen-en Park. (G) Right market. (H) Left market. (I) Saiji. (J) Toji. The numbers indicated the width of streets in feet.

Figure 3: The plan of the Heian capital

Figure 4: Satelite map with the Kawasaki Pottery marked out to see the context.

Ventilation and daylight

As Kawasaki-San explained, the Japanese garden is a part of the ventilation strategy as well as supplying all the rooms with natural lightning.

徳川幕府 旅館

Tokugawa-Cho Guesthouse

Architect: Tomoaki Uno

Location: Nagoya, Aichi prefacture, Japan

Built: 2021

Program: Guesthouse

Category: Old structure, transformation, new structures

Focus: Reading context, construction detail

Yasou Hagiwara

View to the garden and office building from the main house

Intro

In advance of our field trip to Japan we decided to contact the Japanese architect Tomoaki Uno to see if he would be interested in meeting us. We were interested in discussing his approach to architecture and wooden projects. He said yes! Uno-san started his office Tomoaki Uno architects in 1990, and has recently received a lot of attention on his latest projects. His studio is a combination of architectural office and construction firm, which we think is very interesting to learn more about. Most known is the ‘Yomogidai house’, a residential house standing on pillars with extended roof eaves.

When we arrived in Nagoya and finally got to sit down to talk with Uno-san about his methods for designing, we were surprised by his approach. He started his designing processes by drawing the details. This way he could ‘think as a carpenter’ to manage to control the aesthetic expression, costs and final result. Through this method he retained a broader control of the project, not risking losing it to outer influences such as to entrepreneurs or developers. When designing he was clearly inspired by traditional architecture, and was eager to learn about these methods to pass on clever solutions to new modern projects. After

gaining knowledge through several years of experience he built up a resumé which he referred to as his ‘drawers of knowledge’. When designing, he pulled out different drawers to be able to put them together and get the output he desired. Even though being inspired by traditional structures and methods, he stated clearly that what he wanted was to always ‘build something new’. Uno-san explained further that being an architect is not about creating a brand which reproduces its product and expression, but to participate in the development of architecture by experimenting and bringing it further.

When we thought the time to question Unosan was about to run out, he told us to tag along and join a tour to see a selection of his projects. We drove between six of his projects and spent the whole afternoon looking at a broad selection of housings, many of them not even published online.

One of them was one of his most recent interventions: The Tokugawa-cho guesthouse.

In this case study we want to keep a focus on how to design in a context with existing structures in addition to construction details.

“It was not possible to build everything in traditional timber construction, which is not allowed by current legislation. Therefore, I tried to use scientific methods and not to defile traditional Japanese architecture. (...) I want to create spaces I have not seen before.”

Tomoaki Uno

Tomoaki Uno in front of his project.

“All the wood here is cedar, selected from all over Japan. Some of the larger pieces, in particular, have been carefully nurtured over several generations by lumberjacks. I took on this work with a great deal of responsibility.”

Project and context

The Tokugawa-cho guesthouse used to be a family home, but is now transformed into a guesthouse with additional facilities. Besides renovating the main house, Tomoaki Uno constructed three new spaces: a tea ceremony house, a connected storeroom and a separate office. Each structure is built up by using different timber construction techniques, but with the same type of wood: cedar.

The tea ceremony house is built upon traditional principles, where Uno-san engaged a craftsman from Kyoto to assemble the post and beam construction that was later brought to the site. The two latter structures are built using modern techniques. After the earthquake in Kobe in 1995 new building standards were set to be more resistant towards the enormous vertical and horizontal forces. After this point it was mandatory to use metal enforcement in timber joinery. Therefore, all new buildings in Japan contain metal enforcement and the joints are not pure wooden joints unlike the traditional structures.

Cedar wood

The wood used is as mentioned the softwood called cedar. Because of its high accessibility, quality and durability, it is one of the most commonly used materials in Japan. It has a high resistance against weather in addition to being insect repelling. This is because its high level of harpic. It’s also famous for its workability, being soft and easy to shape. Lastly, it has a low shrinkage factor and high decay resistance. On the other hand, cedar requires regular maintenance and is weak to use as a construction material.

Another famous type of wood used in traditional timber construction is the Japanese cypress, which is a stronger type of wood. Besides cedar and cypress, Japan remains a big variety of trees suited to different kind of constructions. Because of this enormous amount of wood recources the preferred building material was traditionally always wood.

Tomoaki Uno

The garden and the tea house.

A Japanese forest.

engawa (south)

tokonoma

chairman’s room

mizuya

Japanese room

doma/ earth floored area

main entrance

guest’s entrance

tea room engawa (north)

tokonoma

corridor corridor

guest toilet

tea room

EV service entrance

mizuya

host’s entrance

guest washroom

kitchen

daikokubashira/ central post w. sacred significance idoko/ living room w. sunken hearth Plan

Reading the excisting context

It was interesting to see the way Uno-san was able to read the context of the plot and place new structures without defying the premise of the existing main building. By conversing through materials, finishes and tones, the new context Uno-san has added forms a new layer to the context and enforced the qualities of the site.

Details of the restauration work by Tomoaki Uno

The office building

In this case study we want to take a closer look at the office building, which also works as a gate for the site. The focus will remain on the timber construction, and especially the post-beam detail between the two floors.

The office space looks to the “nagayamon” gate, which is a large traditional gate facing the street to control traffic in and out of residences of feudal lords. The new gate’s first floor contains a porch, a small office, a storage room and toilets, while the upper floor contains a larger office space. The first floor is remarkably narrow. The wooden

expression with the posts, exposed beams and extended eaves is a clear translation of traditional proportions. It even brings associations to Todai-ji’s gate typology.

One can though question the dimensions in this structure. Regarding the size of the building, the beams and columns can be read as overdimensioned. Does this have a functional aspect, or is it simply in favour for the wooden expression? Who decides whether a building is inspired of old techniques or if it is intimidating them?

The office building seen from the garden

The office building seen from the street. Yasou Hagiwara

Section CC and DD 1-200

Construction detail

Tomoaki Uno starts early in the design process with the details. We wanted to take a closer look at the building details to understand the building process. Through conversations with Tomoaki Uno, our supervisor and a constructing engineer we were able to take a deeper look in the hidden joinery in this building.

Beneath, one can see an axonometry of the timber joinery between the post, beam and cross beam between the first and the second floor. On the other side, one can read how the wall and floors are constructed.

Detail mochups and notes from Uno-san’s office.

Figure 5: construction. Yasou Hagiwara Conceptual axonometry

floor: cedar t = 12 w = 145

base: plywood t = 12

insulation: forestboard t = 15

45 x 45 joists

base: structural plywood t = 24

eaves (inside): cedar horizontal panel t = 30 w = 180

inner walls: cedar horizontal panel t = 30 vertical joists 24 x 150

insulation: forestboard t = 20

breatheble waterproof sheets

external wall: cedar horizontal panel t = 30

eaves (outside): kirishima cedar t = 30 w = 227

inner walls: cedar horizontal panel t = 30

insulation: forestboard t = 45 structural plywood t = 9

breatheble waterproof sheets

external wall: kirishima cedar t = 32

Litterature list

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Archery Hall & Boxing Club / FT Architects. (2013) ArchDaily. Accessed 22.11.22 from:https://www.archdaily.com/444857/timberstructure-archery-hall-and-boxing-club-ft-architects> ISSN 0719-8884

Bracket architecture. (2009) Britannica. Accessed 10.10.22 from: https://www.britannica.com/technology/bracket-architecture

Cedar Wood: 8 properties, uses, advantages, disadvantages & types of cedar. (2022) Dream Civil. Accessed on 20.11.22 from: https:// dreamcivil.com/cedar-wood/

Chuji Kawashima. (1986) Minka: Traditional houses of rural Japan. Tokyo. Kodansha International LTD.

Japanese Finishes. (2015) Supplier of Japanese Finishes’ information page. Accessed on 22.11.22 from: https://www.japaneseplastering.com/fundamentals/japanese-finishes

Journal article about Analysis of the Bacterial Community Found in Clay Wall Material Used in the Construction of Traditional Japanese Buildings. (2008) Oxford Academic. Accessed on 12.10.22 from: https://academic.oup.com/bbb/article/72/2/557/5941302?login=true

Journal of the Japan Society for Composite Materials. (2009) J-Stage. Accessed on 10.10.22 from: https://www.jstage.jst.go.jp/article/ jscm/35/1/35_1_27/_article

Kawasaki Pottery Shop. (2022) Kawasaki’s homepage. Accessed on 10.10.22 from: https://toutensei.com/english/

Pottery. (2022) Traditional Kyoto. Accessed on 20.11.22 from: https://traditionalkyoto.com/shopping/pottery/

Shikkui Royal Japanese Plaster. (2022) Supplier of Shikkui Plaster’s homepage. Accessed on 22.11.22 from: http://shikkui.net/shikkui-plaster/what-is-shikkui-plaster.html

Tetsuro Yoshida. (1952) Japanische Architektur. Tubingen. Verlag Ernst Wasmuth.

Timber structure II. (2013) FT architects. Accessed 01.10.22 from: http://ftarchitects.jp/en/timber-structure-%E2%85%A1/ Tokugawa-cho Guesthouse. (2022) Archdaily. Accessed on 11.10.22 from: https://www.archdaily.com/976697/tokugawa-cho-guesthouse-tomoaki-uno-architect

Tomoaki Uno applies traditional Japanese craftsmanship to Tokugawa-cho guesthouse. (2022) Designboom. Accessed on 20.11.22 from: https://www.designboom.com/architecture/tomoaki-uno-tokugawacho-guest-house-japan-09-23-2021/

Interview with FT architects, 08.09.22, Tokyo

Interview with Kawasaki, 13.09.22, Kyoto

Interview with Tomoaki Uno, 22.09.22, Nagoya

Endnotes

1 Chuji Kawashima. (1986) Minka: Traditional houses of rural Japan. Tokyo. Kodansha International LTD. p. 12

2 Archery Hall & Boxing Club / FT Architects. (2013) ArchDaily. Accessed 22.11.22 from:

https://www.archdaily.com/444857/timber-structure-archery-hall-and-boxing-club-ft-architects

3 Shikkui Royal Japanese Plaster. (2022) Supplier of Shikkui Plaster’s homepage. Accessed on 22.11.22 from: http://shikkui.net/shikkui-plaster/what-is-shikkui-plaster.html

4 A. L. Sadler. (1962) A Short History of Japanese Architecture. Tokyo. 1. utg. Charles E. Tuttle Company.

Figure list

Figure 1: Construction system. Accessed 22.11.22 from:

https://www.archdaily.com/444857/timber-structure-archery-hall-and-boxing-club-ft-architects> ISSN 0719-8884

Figure 2: The boxing hall space. Accessed 22.11.22 from:

https://www.archdaily.com/444857/timber-structure-archery-hall-and-boxing-club-ft-architects> ISSN 0719-8884

Figure 3: The plan of the Heian capital. A. L. Sadler. (1962) A Short History of Japanese Architecture. Tokyo. 1. utg. Charles E. Tuttle Company.

Figure 4: Satelite map with the Kawasaki Pottery marked out to see the context. Accessed on 21.11.22 from: google.com/maps

Figure 5: Contruction detail. Accessed on 11.10.22 from:

https://www.archdaily.com/976697/tokugawa-cho-guesthouse-tomoaki-uno-architect