建筑物的拆除重建会消耗大量资源和能源。近年来,日本积极开发、应用既有建筑更新改造技术,尽可能不再拆了重建,取得了很好的效果。文章首先介绍了日本既有建筑更新改造的含义和市场变化,进入21世纪其市场份额已经超过20%,2009年度达到27.4%;进而,通过实例阐述了日本企业在既有建筑改造方面的理念创新和以建筑节能、减少碳排放、使用环保材料等为重点所做的工作;最后重点分析了空调系统用生态通风管道、节能水喷雾冷却系统、屋顶悬吊式工位空调系统、全地面出气空调系统和紧凑型双层玻璃幕墙等节能减排技术的应用及其效果。这些将对我国推进既有建筑节能改造有所帮助。 Demolition and reconstruction of buildings can consume large amounts of resources and energy. In recent years, Japan has actively developed and applied existing building renovation and reconstruction technologies, and has not taken apart and rebuilt it as much as possible and achieved good results. The article first introduces the meaning and market changes of the renovation of the existing buildings in Japan. In the 21st century, its market share has exceeded 20% and reached 27.4% in 2009. Furthermore, it illustrates the concept innovation of Japanese enterprises in existing building renovation through examples And focus on building energy efficiency, reduce carbon emissions, the use of environmentally friendly materials, and so focus on the work; the last emphatically analyzed the air conditioning system with ecological ventilation pipes, energy-saving water spray cooling system, roof suspension station air conditioning system, all terrain air conditioning System and compact double glass curtain wall and other energy-saving emission reduction technology and its effect. These will help to promote the retrofitting of existing buildings in our country.