To address the topic of building age-friendly cities that better meet the needs of the elderly in a sustainable-city-oriented manner, this paper focuses on the interaction between the needs of the elderly and urban facilities in the urban built environment in order to propose a comprehensive evaluation method regarding the friendliness of urban facilities with respect to the elderly in large urban areas. The development of the proposed method was guided by the distribution characteristics of the elderly population and combines a spatial measurement evaluation, which is based on the spatial distribution characteristics of urban facilities for the elderly, and a post-use measurement evaluation, which is based on the characteristics of use by the elderly. Taipei City and New Taipei City are then taken as examples for evaluation. From the final evaluation results of the Boston four-quadrant analysis, the areas with higher spatial and post-use metric evaluation values were defined as areas of high concern, while those with lower spatial and higher post-use metric evaluation values were defined as advantage-maintained areas. These two types of areas accounted for about 58% of the total area, and are distributed in the Taipei urban area and northeast New Taipei City. The areas with higher spatial and lower post-use metric evaluation values were defined as priority improvement areas, while those with lower spatial and post-use metric evaluation values were defined as key complement areas. These two types of area accounted for about 42%, and are mainly distributed in the northwest part of Taipei City, as well as the western and southern mountainous areas of New Taipei City. Accordingly, region-specific planning policy recommendations were provided.