＊ Professor, Department of Architecture and Architectural Engineering, College of Industrial Technology, Nihon University＊＊ President, Tokyo Dismantling Works co., ltd.Keywords: Demolition, Transition, Wooden Structure, Material, JapanNow, half a century after Japan’s period of rapid economic growth after World War II, buildings are being demolished frequently. Among them, there are many issues regarding the subsequent use of demolition materials, the current situation being that the technology for second-hand materials is not progressing. This problem has evolved into a global environmental crisis; this scrap-and-build trend is expected to continue in the future.This report records a survey from the Meiji era to the middle of the Showa era (year that Tokyo Demolition Cooperative was established and its subsequent years). Initially, no contractor specialized in demolishing buildings, and it was said that the Japanese steeplejacks (Tobi) and carpenters lead the demolition work. At that time, the steeplejacks were said to demolish a building’s framework while the carpenters broke the interior and other decorations. Around 120 years ago (early Meiji era), the first contractor specializing in building demolition and structure relocation was recorded.In the early Meiji era, the authority of the feudal lord (daimyo) fell, along with the shogunate’s overthrow. As a result, the feudal lord (daimyo) could not manage the land he owned and put it up for sale. As time passed, some people bought the land and built a new building. During this era, timber was precious commodity due to its high price and shortage. Therefore, there was no choice but to procure materials by dismantling the existing building. The demand to use second-hand materials then increased, and a market for selling and buying second-hand materials has gradually become necessary. Thus, a second-hand store selling old fittings and old timber opened in Kurumazaka, Ueno, Tokyo, and a market was established. The re-used wooden materials in these markets (materials from the dismantled buildings) were traded at about 70% of the price of the new materials.In this way, old timber was traded at a price comparable to new timber, so when demolishing a building, workers used a demolition method that would not damage the timber materials. If damaged, the value of the wood decreased, therefore, the workers put their hearts into dismantling the wood without damaging it. If a blade like a saw were used to demolish a building, the material would be damaged, so there was a demand for a tool that would not damage the material. The razing/ demolition industry worked with a blacksmith to develop a tool that would satisfy their needs; these tools are shown in Fig. 1, Fig. 2.2.1 History Prior to the Razing/ Demolition IndustryFig. 1 Tool used to pull out a Japanese nail─ 43 ─（Received March 17, 2021）日本大学生産工学部研究報告Ａ2021年 12 月 第 54 巻 第 ２ 号1. Introduction2. History of Wooden Building Demolition IndustryDocumentTransition of Japanese Architectural Demolition “Kaitai”- Until the Establishment of the Tokyo Demolition Cooperative -Noboru YUASA＊ and Tokuhiko OGUMA＊＊
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