The function of external walls has big effects on the disaster prevention and the scenery of built-up area. It is necessary to maintain these functions by suitable refurbishment. The purpose of this study is to analyze the refurbishment cycles of built-up areas in Tokyo, and clarify the differences among regions. The most prominent difference among built-up areas has been seen in the first cycle of refurbishment act. As refurbishment act has been done many times, differences among the areas were decreasing. This is considered that the vicinity conditions of a built-up area has influenced.
