Design construction and civil engineering

## Environmental Sciences

# The development of a ‘local production of wooden building for local consumption of timber’ type system - Technology transfer of the j.Pod system -

Keyword: Earthquake-proof (Semimonocoque construction), Constructability (Simple system), Quality guarantee (Modularization), Use of local timber (Timber from forest thinning)

Masami Kobayashi, Professor and Hirohide Kobayashi, Assistant Professor, Graduate School of Global Environmental Studies, Kyoto University

Organizations Involved

○ Kazumi Matsushige, Director, International Innovation Organization, Kyoto University

○ Kenichi Katagihara, Representative, SERB Co., Ltd.

○ Yoshikazu Takagi, General Manager of Construction Department, Torisumi Laminated Lumber, K.K.

○ Yoko Masuda, Representative, Tohrisya First-class Architect's Office, LLC

【Abstract】 This j.Pod technology refers to a unit-type construction system with the aims of a local circulation of industry and a restoration of wood culture. The purpose of this technology is to provide the security of earthquake-proofing for wood buildings by using the local timber grown in Japan (effective use of thinned wood). This technology is based on a design system which adequately evaluates the performance of each timber, which then shows the variation according to region and type. This technology has developed through the cooperation of Kyoto University (KU) and private companies. The Intellectual Property Department (IPD) of the International Innovation Organization (IIO) of KU handles the patent applications and the Super Coordination Office (SCO) of IIO handles technology transfer. KU has three j.Pod model houses. The first one was built in the administrative office area, the second in the Agricultural Department area, and the third in the research forest area in Wakayama Prefecture. Those houses are used mainly as seminar rooms.

## [Summary of the technology transfer]

Technological Impact

•Active use of local timbers: The j.Pod technology provides a unique rib frame structure, and after the evaluation of the strength of Japanese cedar from forest thinning, rib frames made by this cedar will be used for wood building. Usually, cedar is said to be particularly less strong and to have less usage applications.

•Returning of appropriate profit to forest owner: Appropriate timber cost necessary for continuous forest management will be added to the rib frame price, then the profit will return to the forest owner, who is suffering from the flagging timber price caused by imports.

•Rationalization of timber distribution system: The small volume and lightweight structure of rib frames will realize the direct delivery system from the forest owner to the end user without going through the complicated distribution network.

•Earthquake-proof wooden building; Even small lumber mills and local builders will be able to construct earthquake-proof wood buildings using j.Pod technology. Furthermore, the rib frame units can be assembled in about an hour, and can be used as emergency temporary houses in case of disaster.

Market Impact

The model house in Hyogo prefecture, which applied the j.Pod technology, achieved a 90% utilization ratio of the prefecture's original timber. (Average ratio of use in wood buildings is about 45%).

●Social Impact

The j.Pod technology transferred to local industry is expected to improve the consumption of local timber and to let the local builder participate in this business without excessive equipment investment.

●Special Features of the Collaboration

The SCO of IIO takes up the j.Pod system as a method of technology transfer for cooperation with local society, and this technology transfer to the local administrations and the local forestry associations will make it possible to promote the effective use of local timbers. Examples of the administrative bodies with which KU cooperates are Hyogo Prefecture, Shiga Prefecture, Tanabe city in Wakayama Prefecture and Saijo city in Ehime Prefecture.

## Project Background

Researchers and technical experts from industry and KU won a design competition for wooden building, sponsored by the Architectural Institute of Japan, formed a co-development project, and after IIO joined this project later, began work on technology transfer.

## Funding History

The Funding of this project is as follows:

1.2005: Discretionary expense of the president of Kyoto University. 2.2005~2006: Discretionary expense of president of Kyoto University. 3.2005~2006: Hyogo Prefecture sponsored research expense. 4.2005~2006: Research and development aid fund of Shiga Prefecture Forest Natural Resources

## I ntellectual property protection

Patent File: Japan 1,

「Construction method of a rib frame structure, and its rib frame structure Patent No. 3548172」

Patent Application: Japan 2,

Trademark: 1.「j·Pod」

## Horizontal load test of actual size rib frame

The rib frame structure is highly earthquake resistant, with high yield strength and good deformation performance. Characteristics of the restoration forces of each local timber, obtained from horizontal load tests, are reflected in the structural calculations of the rib frame.

Construction of the rib frame units

Construction of rib frame units in Hyogo prefecture using Shiso-grown local Japanese cedar (Constructed by local builder)

## Turning point in the Project

In utilization of local timber, a stable supply of timber and immediate action on orders have been issued in doing projects. For the success of this project, it is important to draw the total picture of this business, combining the forest and city in a chain system, and to clearly identify a plan for the utilization of wood from the forest in the j.Pod project.

For more information, contact : Toshiharu Yagi, International Innovation Organization, Kyoto University, +81-75-753-9181, yagi@iio.kyoto-u.ac.jp