A user-centered sustainable design research for parent-child interactive seating in urban children’s parks: Development of an integrated GT-KANO-AHP-QFD model

Urban parks have increasingly become pivotal settings for strengthening parent–child relationships; however, most on-site facilities remain predominantly adult-oriented. Accordingly, this study developed an operational, replicable, and iterative research framework for parent–child interactive seating in children’s parks, placing parent–child needs and sustainable design at its core. Anchored in the Double-Diamond process, a GT–Kano–AHP–QFD integrated innovation model was proposed to extract, classify, weight, and translate user requirements for such seating. By integrating these four methods, user needs were captured and addressed more precisely, thereby deepening understanding of design requirements for parent–child interactive seating. A rapid ideation workflow was subsequently implemented, combining large language models with diffusion models to generate concepts. The scheme was evaluated with fuzzy comprehensive evaluation (FCE), which indicated that the embedded, multifunctional interaction concept achieved the highest performance in functional adaptability, emotional interactivity, and life-cycle sustainability (composite score = 0.840). The findings demonstrated that the integrated innovation model simultaneously enhances user satisfaction and reduces carbon impact, providing a transferable procedural paradigm and empirical evidence for the sustainable design of parent–child seating and other micro-scale public amenities.