Societies are ageing fast, especially in developed countries, where population is becoming progressively urban. Also, individuals show different functional capacity, with greater differences during adult life and older age, facing progressive health impairments. Therefore, active ageing becomes an essential lifestyle for autonomous senior citizens, whose growing numbers are showing a grey power that will determine public policies, namely on public space and housing. Alvalade neighborhood, in Lisbon, will be analyzed as an urban area whose modernist housing ensembles could allow simple transformations, taking advantage of the existence of common spaces in each building to be used for the common good of its residents. Two case studies of interventions are proposed and explained, towards an elder-friendly environment, including co-housing and intergenerational housing.