A study on the prolongation of the average span of public buildings' life in functional aspect - an approach based on a change of use

本研究对日本公共建筑变更使用的现状进行了阐释，同时对变更后的规划进行了分析，以期对规划提出理性的看法。首先，讨论了前人的研究、术语的定义、研究和调查的方法，并对以下几个方面进行了说明：1)大量的日本公共建筑不到15年的历史。因此，维护问题尚未浮出水面。但在五年内，需要大规模维修的建筑物将大幅增加。2)考察改变用途的案例，公共建筑物的类型在每个改变因素和情况下都显示出一些独特的趋势。3)引起改变用途的因素可分为以下三类。(1)建筑没有对区域需求的质和量变化做出反应；(2)存在阻碍重建的外部原因；(3)施工较新。4)通过典型案例介绍了项目3)的具体细节。5)对改变用途前后的方案进行了以下几个方面的比较。(1)面积，(2)道路和建筑地段之间的关系，(3)房间和空间的平面型。结果表明，根据用户的类型、停留时间和目的，要改变的部件会有所不同。6)根据维修工作的等级来表示实现改变使用所需的工作。7)显示改变使用的设计技术。

This study explains the actual status of a change of use of public buildings in Japan, and at the same time analyzes changed plans by change of use to present a rational view on planning. First, previous research, definitions of terms, and method of research and survey are discussed, and the following items were explained.1) A large stock of Japanese public building is less than 15-years old. Thus, maintenance problems have yet to surface. But in five years, buildings requiring large-scale repairs will increase dramatically.2) On examination of changed cases of use, type of public buildings reveals some unique trends in each factor and circumstance of change.3) The factors which cause a change of use can be classified into the following three categories. (1) The building has not responded to the qualitative and quantitative change in regional demand, (2) external reasons that prevent that prevent reconstruction exist, (3) the construction is new.4) Specific details of item 3) were presented through a case study of typical cases.5) A comparison of the plan before and after a change of use was made the following items. (1) Area, (2) relationship between road and building lot, and(3) plan-type of rooms and spaces. As a result, it indicated that there were differences in the part to be changed depending on the type, staying time and purpose of the user.6) Work required for realizing a change of use was expressed in terms of the grade of repair work.7) Design-technique for a change of use is showed.