Resumen: In light of the symptoms of obsolescence shown by housing estates built in the 1960–70s, numerous approaches have contributed to the debate on this urban form characteristic of functionalist urbanism. The study of open spaces—an aspect that, to a large extent, is responsible for the quality of housing estates—is still an ongoing research approach. However, fifty years after their construction, it is possible to see how its initial homogeneity has led to very different situations that are difficult to categorise. Only by addressing the specific urban processes that each housing estate has undergone will it be possible to promote conservation and regeneration strategies that are suitable for each case. This paper aims to develop a methodology that will help to offer a diagnosis of the urban quality of housing estates. The approach is based on urban morphology from a diachronic perspective, since the transformation processes are assessed from the initial situation to the present one. Through the basic elements that define the urban form the proposed methodology works with nine ‘physical’ variables. The specific analysis provided by the methodology helps in the definition of regeneration strategies for open spaces. The methodology was tested for three case studies in Spanish cities. Idioma: Inglés DOI: 10.1016/j.cities.2020.102657 Año: 2020 Publicado en: Cities 103 (2020), 102657 [17 pp] ISSN: 0264-2751 Factor impacto JCR: 5.835 (2020) Categ. JCR: URBAN STUDIES rank: 3 / 43 = 0.07 (2020) - Q1 - T1 Factor impacto SCIMAGO: 1.77 - Development (Q1) - Urban Studies (Q1) - Tourism, Leisure and Hospitality Management (Q1) - Sociology and Political Science (Q1)