To ensure existing buildings with normal life functions, existing buildings have, after years of time, to be renewed. First of all, building is made of two separate systems as structure and service facilities, and the latter is given with shorter span of life; therefore, the service facilities has to be renewed 2 to 3 times in the life cycle. Because of the scarcity of earthly resources, sustainable development has become the important objective. This study focus on how service facilities can be renewed to enhance their sustainability. Thus, we have chosen public service facilities of existing residential apartments to study the 'model of diagnosis and renewal'. Afterwards, evaluation results will be classified to four classes according to importance, urgency, and feasibility so that residents can plan with short-term and long-term renewal project to maintain or upgrade their environment quality. In order to substantiate this model and explore demand of renewal regarding the public service facilities of residential apartments, we has conducted questionnaire investigation and inspection on-site in four metropolitan cities in Taiwan, and the results indicate that this model can, indeed, examine and discover the sustainability of service facilities. Besides, we should, based on the above-mentioned ways of classification, conclude the most often meet renewal demands regarding public service facilities which can be founded on as reference of priority for future renewal.