Over 25 years, the WHO's Healthy Cities initiative has shifted from a medical-focused approach to a holistic view of well-being, encompassing all aspects of urban health.

Regional governments can collaborate with urban and rural communities to identify shared interventions for fostering happy, complete, and healthy communities through inclusive dialogue, data analysis, and participatory planning processes.

We advocate that evidence on design's impact on happiness empowers designers, planners, and citizens to co-create better communities. Teaming up with Laboratorio para la Ciudad, an urban innovation lab, we applied this approach in a complex, contested district in Mexico City.