The concepts of healthy cities and smart cities are popular in emerging research in the 21st century. This study focuses on the existing interrelations between the two notions in terms of socio-spatial quality, technology, and innovation, particularly regarding industrial sites that no longer have a role and constitute ‘urban voids’ with high volumetric concentrations. The fast expansion of cities and the de-industrialization phenomena have resulted in such void-producing blights that compromise public health; environmental quality; and social, economic, and living conditions. Therefore, the authors intend to emphasize the relevance of citizens’ and communities’ engagement in shaping new healthy and smart urban environments. The present method relies on a literature review to describe the current theoretical and practical dimensions of such topics, identifying synergies and trade-offs. After this, a case study in China is presented to support the discussion. The site, a former granary, is located in Lianshi, a traditional water-edge town in the central area of the Yangtze River Delta. The proposed example enhances solutions that meet healthy and smart requirements, transforming the former industrial area into a social catalyst, acting as an effective motivator for urban development. One such theoretical approach is exemplified by a project that won a national architecture competition in 2018, the ‘Taihu Cultural Heritage Rehabilitation Competition’. The latter is then validated through practical solutions in a real-world context by analyzing the ‘Cuckoo’ project developed in 2021 for the same area. Overall, the integration of healthy and smart elements is proposed by the authors as an effective method to achieve more holistic and sustainable city development from both theoretical and practical points of view.