SI HOUSING PROJECT Flexsus House 22 Sustainable Housing system

Tadashi Ohara, Kiyotake Suzuki, Office of Housing, Yuuji Oshi, Research and Development Institute,

TAKENAKA CORPORATION 21-I,%-CHOME, GINZA, CHUO-KU, TOKYO

ABSTRACT The present report outlines the outcome of the New Housing Structure Project that

has been implemented with the objectives of developing highty sustainable houses. In this development work, new infill systems were applied to a new support system. New infill systems were developed within the House Japan Project of the Ministry 01 International Trade and lndustry Wexsus" has the meaning of "flexible plus sustainable. " In this report the following are introduced.

a) a new support system for use in support/infill houses with a perspective for the 21st century

b) new infill systemsfthree infill systems developed by Takenaka Corporation among 10 systems in al l )

1. INTRODUCTION From the viewpoint of environmental resources and socioeconomic considerations, prolonged

durability of houses is strongly required. It has become necessary to concretely demonstrate that

houses are property of great value in which residents can continue living into the future. Today in

Japan, there are a great number of multifamily houses that require rebuilding. This is due to various

problems, such as increasing maintenance costs, narrow space, and difficulty of renovating housing

units. In order to realize prolonged durability, it is necessary to construct a new housing system that

solves these problems. The Project was devised with the objective of enhancing the social "stockability" of Japanese

dwelling houses. The development of skeletons with the required standard of stockability called for

advances in multiple durability-related element technologies and the utilization of sophisticated building

1) Exterior view from the north

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construction designing technology concurrently with high precision execution capabilities.

In general, the skeletons of Japanese dwelling houses adopt a rigid frame structure incorporating earthquake-resistant walls. Infills of the dwelling houses are subjected to various restrictions arising

from the existence of beams and earthquake-resistant walls. Such restrictions include a) difficulties in

planning due to the segmentation of the space by beams; b) limitations in the positioning of ducts by the location of sleeves; and C) the difficulty in expanding the accommodation space because of

earthquake-resistant walls integrated into the construction. All these factors work to hamper the modification of infills during the reforming of dwellings. The difficulty of effectively utilizing the space

due to the lack of height from the beam to the floor is also a problem. Skeletons capable of addressing these drawbacks flexibly are thus in demand.

2. PROJECT OUTLINE

As a means of resolving the problerns described above, the most irnportant requirements are to

develop a housing unit system that can provide high changeability as well as a new structural system with high endurance that can improve the flexibility of housing units. The Concepts of this system are

"Flexible design," "Adaptable design," and "Available design."

Flexsus House 22 is the name given to the newly developed housing structure system. This system

guarantees a durability of 100 years and flexibility of room plans corresponding to changes in life stages and styles.

Within the Project, the flat plate frame structure was adopted. Previously, Japanese dwelling houses

avoided the use of flat plate because of the inherent seismic activity. In order to adopt the flat plate structure, a technology to combine the flat plate with high performance base isolators was devised.

Six member companies participated in this Project from the House Japan Association. a) Takenaka Corporation was responsible for the research and technical developrnent of the

skeleton, as well as the design and construction of the experimental skeletons.

b) Takenaka Corporation, Matsushita Electric Works, Ltd., Inax Corporation, Kajima Corporation, Tokyo Gas Co., Ltd., and Toho Gas Co., Ltd. undertook the research and technical

development of the infill, and the design and construction of the experimental infills.

3. OUTLINE OF THE EXPERIMENTAL CONSTRUCTION

PROJECT TITLE DEVELOPMENT OF NEW HOUSING STRUCTURE SYSTEM BUILOING NAME FLEXSUS HOUSE 22 LOCATION SETO-CITY AICHI PREFECTUHE JAPAN BUILDING USE HOUSE EXPERIMENTAL HOUSE STRUCTURAL DESIGN R C F3 BUILDING AREA 659 1 1 m' TOTAL FLOOR AREA l 254.45mJ SPAN 7.2m X 11.6~1 NUMBER OF DWELLING UNITS : H STORY HEIGHT F3/3,350mm

P2X3250mrn F 1 N3.550mm

RATION

TAKENAKA CORPORATION MATSUSHITA ELECTRIC WORKS.LTi3 INAX CORPORATION KAJIMA CORPORATION TOKYO GAS CO..LTO. TOHO GAS CO ,LTD ;+&~<&.. 2 g ~ 4

2) Outline of the experimental construction

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4. PRIMARY TECHNOLOGIES ADOPTED FOR THE EXPERIMENTAL SKELETON

(1) Flexible, high-durability skeleton An innovative structure combining -- a) a flat

plate frame structure; b) high performance base isolators; and C) high-durability concrete - and

providing up to approximately 240 sq. meters of

space.

a. Flat plate frame structure Flat plate, eliminating the need for beams, is

an excellent structure in terms of freedom of infill. However, aseismic measures are indispensable in Japanese dwelling houses, requiring the incorporation o f earthquake-resistant walls. Thus, the

modification of the layout such as the expansion of unit area and the creation of openings

including doorways and windows call for structural reinforcement, rendering subsequent

alterations virtually impossible, This is a maior - .

obstruction de-motivating the expansion of dwelling units despite improvements in the standards of living, and one of the reasons behind the brief service life of dwelling houses in Japan.

A durable flat plate frame structure was

achieved through the combination of high

performance base Isolators with the superstructures, and the development of

'TEX} Firtt fltxr 8

3) Outline of the experimental construction

4) View of the third floor realizing appropriate design techniques. space of 240 m"'

5) Prirnary technologies adopted for the experimental skeleton