As rural populations age at an accelerating pace, the role of public spaces in enhancing the quality of life and promoting social engagement among older adults has become increasingly important. However, a significant cognitive gap persists between the actual needs of elderly users and the intentions of designers, often resulting in suboptimal design outcomes and underutilized spaces. This study centers on the concept of user–designer cognitive synergy, aiming to establish a systematic framework to bridge this cognitive divide and improve the design quality of age-friendly rural public spaces. Employing Grounded Theory, the FKANO model, and the DEMATEL method, this study systematically elicited user needs, classified their attributes, and mapped causal relations to determine priority drivers. Applied in a representative rural case, the framework identified Environmental and Operations Management and Spatial Accessibility as the most critical needs, while Smart-Friendliness and Safety Organization were also shown to play significant roles. These findings directly informed targeted spatial strategies such as barrier-free circulation, robust nighttime safety systems, intergenerational hubs, and an operations backbone. Post-occupancy evaluation confirmed high satisfaction across safety, accessibility, functionality, social participation, and environmental comfort. The results demonstrate the framework’s effectiveness in translating complex needs into actionable design strategies, offering both theoretical insights and practical guidance for age-friendly rural public space development.

As populations age, indoor community public spaces play an increasingly important role in supporting older adults’ daily activities, social interaction, and well-being. This study uses Pubei Community in Changzhou as a case study and develops age-friendly renewal strategies tailored to the community context. Through interviews and questionnaire surveys, the study systematically identifies older residents’ needs regarding the use of community public spaces. The Affinity Diagramming (AD) method is first employed to categorize and organize the information collected from the field investigation, followed by the application of the Fuzzy Kano (FKANO) model to screen and identify core user needs. The Precedence Chart (PC) method and CRITIC weighting method are then integrated to calculate combined weights for the evaluation indicators and rank them, thereby establishing the priority of user needs. Subsequently, user needs and design requirements are incorporated into Quality Function Deployment (QFD) to construct a House of Quality (HOQ), which informs age-friendly renewal strategies and design solutions for Pubei Community’s public spaces. The results indicate that, after four need indicators were excluded, safety needs (0.099), health and emergency needs (0.091), and spatial convenience needs (0.084) ranked among the highest in terms of combined weight. Based on these user needs, 15 design requirements were identified, among which barrier-free access (0.096), health and emergency facilities (0.091), and handrail facilities (0.088) had high relative weights, indicating that these elements should be prioritized in the age-friendly renewal of community public spaces.