【Special Issues:Ecodesign】
Architectural Eco-Design
Toshio Ojima
Professor of Science & Engineering, Waseda University Member, Science Council of Japan
（3-4-1 Okubo, Shinjyuku-ku, Tokyo, 169-8555 Japan）

Abstract
Two types of recyclable residences have been proposed as residential models for the 21st century. One is built in Toyama, and its main structure is made from wood, which is its most important aspect with regard to the natural ecological system. The other, built in Kyushu, has a main structure which is made of steel, which is its most important aspect with regard to the artificial energy-cost chain for industries.
The residence in Toyama uses natural materials: a wooden structure, earthen walls, and a stone basement. It was completed by carpenters and has a high recycle value of 90.6. The residence in Kyushu, on the other hand, uses artificial materials such as steel, aluminum, and glass. It turns out to be a resource-saving residence as its life-cycle can extend up to 450 years with the cooperation of companies.

Key words: recycle, recycle value, ecology chain system