Existing initiatives to improve physical, mental, and social condition of senior citizens, which in Europe fall under the name of Active and Healthy Ageing, are including technological paradigms as main driver for innovation uptake. Among these paradigms, Smart Cities and the Internet of Things are of utmost importance. However, these initiatives may benefit from unified visions, efforts, and frameworks when it comes to defining technological solutions that take the most of both paradigms. We have defined an iterative approach, which combines user centred design techniques, technological development approaches, and a multifaceted adaptation process, to define a solution for Active and Healthy Ageing that makes use of the two paradigms. The solution is being defined in the context of two research and innovation projects, City4Age and ACTIVAGE, during which a solution is going to be defined and evaluated in the city of Madrid. Results show how Smart Cities and Internet of Things contribute to the solution, from a user (user needs and use cases) and a service delivery (technologies, architecture, and suppliers) perspective. In conclusion, we find the cocreation framework extremely useful for the Active and Health Ageing domain, and the proposed implementation of it is functioning, although there is room for improvement.