This paper discusses the demolitions and demolition works of high-rise office buildings. What we found are as follows 1. 59 out of ever-built 604 high-rise office buildings have been demolished at New York City, and there have been built higher ones on their sites in most cases. 2. Demolition methods with conventional construction equipments are adapted in some high-rise buildings, because most of them stand over congested estates. 3. The big volume and long-lifetime of a high-rise office building make some problems on demolition. For instance, illegalizations of building materials that were legal on construction forces many careful treatments of them during demolition works in large quantities.
