The provision of inclusive indoor and outdoor spaces is essential for achieving age-friendly cities and addressing complex health inequalities. Older adults, especially care home residents, are the least active and most sedentary segment of the population, and are more likely to be isolated and experience loneliness. They also present more difficulties accessing spaces to engage in physical activity and social interaction. This protocol proposes the use of co-creation as an overarching approach to position end-users and key stakeholders as decision-making agents in an urban design and spatial planning project. EngAGE4Change focuses on the older adult population (60+ years old) of the Dreta de l'Eixample neighborhood in the city of Barcelona. The participants of this study, known as “co-creators” will consist of two (2) groups of 8 to 12 older adults (residents from 2 selected care homes and community-dwellers from a daycare/community center), 3 relatives, 2 health professionals, 2 care-home staff members, 1 researcher, and 2 urban design and planning professionals. The co-creation process will be geared towards designing common spaces and urban community spaces near care homes to improve movement patterns and reduce social isolation. The group of co-creators will lead the concept ideation, refinement, and project delivery stages with the use of several methods. The project will test process and outcome evaluation guidelines for co-creation, as well as the incorporation of Augmented Reality/ Virtual Reality (AR/VR) technologies to deliver a spatial prototype as a result of the co-creation process.