OSAKA, KANSAI, JAPANEXPO 2025
A Guide to CLT-BasedPavilion Architecture

CLTJapan Cross Laminated Timber AssociationWhy CLT will be in the spotlightat Expo 2025 Osaka, Kansai, Japan“Designing Future Society for Our Lives” as
expressed through large-scale wooden architecture

As a building material, wood feels alive
Faster to build, gentler on the environment
Effective use of wood contributes to SDGs
Established in Europe as a construction method
for large wooden structures

CLT is a new building material suitable for pavilion construction
CLT (Cross-Laminated Timber) is a wood-basedmaterial made by laminating and gluing together
sawn boards so that the fibers run perpendicular
to each other. It is used for walls and floors ofcondominiums and commercial facilities, mainly inEurope and the United States, and is increasingly
being used in Japan as a construction material
that is suitable for large wooden structures. In
addition, the use of locally sourced materials for
CLT manufacturing contributes to promote local

Goals of Expo 2025 Osaka,
Kansai
Theme

Designing Future
Society for Our Lives
Sub-themes

Saving Lives
Empowering Lives
Connecting Lives
Concept

A laboratory for a future society● A space where 8 billion people from aroundthe world will not only view exhibits but will cocreate our future society.
● Even before the Expo begins, an online
platform for sharing challenges and solutions
from around the world will be launched.
●A place where the world’s knowledge such as
cutting-edge technology will be brought together,used to create new ideas, and shared, all to help
resolve global issues facing mankind.
In line with its theme of “Designing Future
Society for Our Lives,” Expo 2025 Osaka,
Kansai will aim to educate the public on theimprovement of healthy life expectancy, pursue
business possibilities and create technologicalinnovations. Efforts will be made to share
information online in addition to exhibits at theExpo site, with an expected economic ripple
effect of approximately 2 trillion yen.

Courtesy of the Ministry of Economy, Trade and Industry

2017 Japan Cross Laminated Timber Association Awards

Life in a CLT Forest: Bringing the Joy of Wood to Urban Homes

Working Group for Modern Wooden Structures, Design Division, TAISEI CORPORATION[TAISEI DESIGN Planners Architects & Engineers]
Yasutada Sekiyama, Hiroki Matsuo, Satoru Shimizu, Atsushi Tsuchiya, Marina Muta,
Ryo Deguchi, Kohei Shimamura, Hiroshi Umemori, Yumi Sakaguchi, Kenya Kawasaki,Masahiro Kaite, Ryoko Nojima, Nobuhiro Yamazaki, Kosuke Tazawa, Kota Tange

industries and empower its communities, andhence, many local governments are now starting
to employ. CLT is the ideal material for the themeof Expo 2025 Osaka, Kansai, “Designing Future
Society for Our Lives.” The buildings themselves
are expected to attract attention as a symbolic
expression of “a society where the United Nations’Sustainable Development Goals (SDGs) can beachieved successfully.”

No Poverty

Zero Hunger

Good Healthand Well-being

Quality
Education

GenderEquality

Clean Waterand Sanitation

Affordable andClean Energy

Decent Workand Economic
GrowthIndustry,Innovation andInfrastructure

ReducedInequalities

SustainableCities andCommunities

Responsible
Consumptionand Production

Life BelowWater

Life on Land

Peace, Justiceand Strong
Institutions

Partnerships
for the Goals

Climate Action01

Creative pavilion architecture
made possible by the use of wood
The texture of wood allows creating a variety of original,
imaginative designs2019 Minister of Land, Infrastructure and Transport Award “CLT Wall Tower”
Yoji Yamaguchi, Wataru Minegishi, Natsumi Hirose, Shoma Ogino, Kaori Furuta [Obayashi Corporation’s Middle-high-rise Wooden Architecture Team]2019 Minister of Agriculture, Forestry and Fisheries Award “komorebi-CLT that sunlight shines through-” mimoa, Hiroyuki Moriyasu/Takayuki Mizuno

2019 Special Award, Japan CLT
Association Award“CLT-Geometric-Dome” by Hirotaka
Kukimoto and Akihito Muromachi[Toda Corporation]

02

CLT that points the way to thefuture of wood construction

Kiyonori Miisho,Professor EmeritusShibaura Institute ofTechnology

The use of CLT can significantly reduce CO 2
emissions during manufacturing and construction
compared to steel or reinforced concrete
construction. Combined with the large amountof carbon stored in CLT itself, this allows for themost sustainable buildings possible.
Leveraging the characteristics of hitherto unseen
large CLT wooden panels allows creatinglarge wooden structures. Of course, CLT canalso be used in combination with appropriately
placed steel, concrete, and other materials tocreate memorial or symbolic structures. Designpossibilities are endless. CLT is becoming
more and more popular in Europe and theUnited States, but has only just started gaining
momentum in Japan. The concept of this World
Expo is “A laboratory for a future society.” Newideas are needed to solve the problems sharedby all humanity. I hope we will be able to give theworld a glimpse of our future society by making
proactive use of CLT.

CLT IDEA CONTEST
The CLT Idea Contest has been held since 2015 to promote CLT anddevelop new techniques. The examples on this page show the best
entries from the past. Professor Emeritus Kiyonori Miisho of the Shibaura
Institute of Technology is the current chairman of the judging committee.

2019 Minister of the Environment Award “CLT Web with Nature Drops : Porous voids visualize the natural environment”
Keisuke Inoue, Masamichi Oura, Hisatoshi Nakao, Takahiro Sashio, Tomoya Shitanishi, Mikiko Kato [NIKKEN SEKKEI LTD]

2019 Special Award
Japan CLT Association
Award

FOLDING SHELL
Wan-Ching Lin [National
Cheng Kung University/
PROTOTYPE STUDIO]
Wong King Tong/Jiang Yuan
Yi [PROTOTYPE STUDIO]

03

CLT is a sustainable material with ex
Also contributes to empowering local communities
About CLTCLT (Cross-Laminated Timber)is a wood-based material madeby laminating and gluing together
sawn boards so that the fibers
run perpendicular to each other.
In addition to supporting buildings
as a structural frame, CLT can be
expected to have multiple otherbenefits, including heat insulation,
flame shielding, heat shielding
and sound insulation. Further

major advantages include shorter
construction periods thanks to theuse of prefabricated structures, andlighter materials than those used in
RC structures. When wood surfaces
are left exposed, CLT createscomfortable spaces that allow
visitors to experience the texture ofwood. Wood is also a sustainable
and recyclable resource, and can beused to build low-carbon buildings.

Excellent seismic
resistanceExcellent insulation
performance

Structures are supported by the entire
surface of thick panels, making it
possible to build earthquake-resistantbuildings. A shaking table test thatsimulated the Great Hanshin-Awaji
Earthquake did not result in any
significant damage, demonstrating
the high seismic resistance of CLT.

The insulation performance of wood is
10 times higher than that of concreteand 400 times higher than that ofsteel. This allows creating comfortableindoor spaces that are cool in thesummer and warm in the winter.

Short construction times●With CLT

Cross
Laminated
Timber
The panels can be manufactured andprocessed at the factory, even forlarge surface areas, so installation
on site is easy and fast. In turn, thismeans less noise and waste.

Three weeks●With reinforced concrete

Three months

Expanding the possibilities of construction in combination with other methods
CLT comes in large, thick wooden
panels and is used as construction
material for buildings. In addition
to CLT panel construction-based
design and building works, CLT
is also used in other construction

RC construction + CLT

methods. It is mainly employed as amaterial for walls, floors and roofs,
and can be used for both traditional
wooden frame construction andtwo-by-four construction. In large
buildings, a range of possible

Steel frame construction + CLT

applications can be considered. For
example, CLT can be used for walland floor panels in steel-framed
structures, and wooden structures
can be built on top of RC structures.

Two-by-four construction +CLT

Relaxation of restrictions
on temporary buildings
For temporary buildings to be set
up at the Expo site, the provisionsof the Building Standard Law on fire
prevention, etc. will be relaxed in cases
where the Designated Administrative
Agency (Osaka City) deems thatthe building does not interfere withsafety, fire prevention and sanitation(Article 85, Paragraph 5 of the BuildingStandard Law). Please Inquire with
Osaka City’s contact point for more
information.

Traditional wooden frame
construction + CLT

Can also be used in civil engineering
In addition to buildings, use of CLT
in civil engineering is also beingconsidered. Research is currently
underway on the use of CLT
floorboards for bridges, and CLT
has been found superior to concrete
flooring in terms of transportation
and bridge construction work. With
these characteristics, the use of
CLT in civil engineering is expected
to expand in the future.

04

City of Osaka, City Planning
Bureau, Building Guidance
Division, Building Verification
Department

tensive applications
Helping empower local communities
by using locally sourced materials
Although Japan’s forest resources
are reaching maturity, they are
not yet being fully utilized. It istherefore important to promote
the use of wood and the cyclicaluse of resources by creating new
demand. More extensive use ofCLT, which entails the utilizationof large quantities of wood, canbe expected to promote theforestry and wood industry in hilly
and mountainous regions, create
new jobs, foster sustainable local
businesses and help empower
local communities.

Contributing to the SDGs
The timber that makes up CLT isa recyclable forest resource. The
forestry industry and the forests
where the trees are grown willcontribute to achieving virtuallyall of the SDGs, and especially
Goal 15 (“Life on Land”). CLT isa material that has small impact
on the environment, and leads

to various benefits such as thereduction of CO2 emissions andthe restoration of forest functions.
CLT will help us achieve asustainable society from thestandpoint of both the environment
and the empowerment of localcommunities.

No Poverty

Zero Hunger

Good Healthand Well-being

Quality
Education

GenderEquality

Clean Waterand Sanitation

Affordable andClean Energy

Decent Workand Economic
GrowthIndustry,Innovation andInfrastructure

ReducedInequalitiesSustainableCities andCommunities

Responsible
Consumption
and Production

Climate Action

Life BelowWater

Life on Land

Peace, Justiceand StrongInstitutions

Partnerships
for the Goals

Sustainable Development Goals

15

Life on Land
Protect, restore and promote sustainable use ofterrestrial ecosystems, sustainably manage forests,
combat desertification, and halt and reverse landdegradation and halt biodiversity loss.

Supporting highly original
pavilion architecture
We can consult with you on the entire process from planning to design, estimates and construction

Joint support provided bythe Japan Cross Laminated Timber Associationand the Association of Local Leaders
The Japan Cross Laminated Timber
Association and the Association of Local
Leaders for Regional Development ThroughCLT will work together to support the client
for the construction of pavilions using CLT at
Expo 2025 Osaka, Kansai.

●●Japan Cross
Laminated
Timber AssociationDesign

The Association of Local
Leaders for Regional
Development Through CLTThis is an association that aims to promote
the development of CLT-related industries
while boosting regional economies andempowering local communities. Participatingorganizations are 29 prefectures, including
Kochi Prefecture, and 81 municipalities,including Maniwa City in Okayama Prefecture.
The Association mainly provides support forthe supply of wood.

●●

Technologicaldevelopment

The Association will act as a general pointof contact for CLT, providing comprehensive
advice on the construction of the pavilions,
including design, introductions to contractors
and the supply of materials.

●●

The Japan Cross LaminatedTimber Association●●Client

Construction

Supply ofwood

Manufacturers(8 JAS-certified companies)
Housing companies
General contractors andconstruction companies
Design companies
Trading companies
329 companies in total

Consultation
services

The Association ofLocal Leaders

for Regional Development Through CLT

Cost

Supply ofmaterials

We can also support planning, design and construction contractors
Public use of CLT began with the promulgationand implementation of a public notice about
CLT based on the Building Standards Actin April 2016. The CLT panel construction
method is recommended for design andPlanning

construction, and is being employed byarchitect’s offices and construction contractors
throughout the country. The Japan Cross
Laminated Timber Association can introduce
design and construction companies to meet

DesignEstimatethe client’s needs, as well as liaise between
the client and the Association’s member
companies.

Construction

Completion

I N F O R M AT I O NInquire here about the construction of pavilions for the Expo 2025 Osaka, Kansai!

Consultation Service for All Things CLT Free of Charge
9-1803-5825-4774
FAX 03-5825-4775

Hours: 9:00 a.m. to 6:00 p.m. (except for Saturdays, Sundays,holidays and year-end/New Year holidays)

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Japan Cross Laminated Timber Association
Higashi-Nihonbashi 2F, 2-15-5 Higashi-Nihonbashi, Chuo-ku, Tokyo 103-0004, JapanTEL: 03-5825-4774 FAX: 03-5825-4775 http://clta.jp E-mail: info@clta.jp