The Department of Technologies of Architecture and Design “P. Spadolini” of the University of Florence cooperates with Universidade Federal do Parà of Belèm (Brazil), and with the Tongji University of Shanghai (China), on the themes of sustainable conservation and valorisation of housing in historical city centres. Spatial and cultural continuity of architecture and urban fabric is a collective memory and the identity of many cities, in the present world. The aim is to highlight local identities, based on the historical heritage, and global connections and multicultural approach as a resource of the urban life. Shanghai history shows the cultural, social and economical interaction between the East and the West., in particular the Lilong district reveals the evolution of lifestyle, urban form, architectural design and technological development, playing an important role to understand the Chinese urban history in the dynamics of local/foreign interactions within the market. Belém, a colonial Portuguese city of the 17th Century located at the estuary of the Amazon River, was a strategic area for the trade of Amazonian products. Many Europeans visited and lived in here. The Cidade Velha district plays an important role in order to understand the Brazilian urban history made of interactions between the local society of Indios and European colonizers. Nowadays, the conditions of the Lilong and Cidade Velha districts are critical. The research programme objectives are: - to share the urban, architectural and cultural heritage scientific methodologies and best practices; - to study, analyse and compare different urban fabric, architecture types and building techniques; - to develop the training and the information activities addressed to both individuals and organisations; - to develop guidelines for sustainable preservation and renewal action. A multicultural and multidisciplinary approach is used in the project: a large group composed by four European Universities besides the University of Florence started to work together in collaboration with the Tongji University; in the Belém project a group composed by city planner, architects, surveyors, historians of architecture. We propose the use of different scientific approach and tools from different areas. In this experience some strategic suggestions and projects are worked out to preserve and renew the historical housing and the urban environment improving cities cultural and natural resources.