The number of ""aging"" buildings in Taiwan is growing. In addition to the natural disasters, e.g., earthquakes, other factors that may undermine building structure include natural aging and man-made damage. The aging buildings may raise problems of residents’ health, living safety and economic development. The purpose of this study focuses on the key factors to keep the essential dwelling functions of an old building working while ensuring its structural safety, architectural aesthetics, and environmental protection at the same time. The relative weights of each evaluation indicators will be decided through using the method of Analytic Hierarchy Process (AHP). This study reaches the following conclusions: 1.""Structural performance"" is the most important factor deemed by experts evaluating the necessity of revamping old buildings. The other key factors, ranked in order, include fire prevention, risk of falling objects, and budgetary resources. 2. The government can use incentive subsidies and tax reduction measures to encourage residents to apply for revamping old buildings. Through the conclusions of this study and policy recommendations, it is expected to provide feasible ways to implement the maintenance policy for the relevant industries, government, and academia.