We no longer live or work like 20 or even 5 years ago. Society's expectations in terms of comfort, diversity and flexibility are much higher, and are constantly changing. Transforming buildings today, and being able to keep transforming them tomorrow is essential, for obvious reasons of environmental impact. The most virtuous square meters are those that are used to 100% of their potential, over the entire life cycle of the building. In large cities, transformation could become the rule, and demolition-reconstruction the exception. Preserving open ground spaces and reinventing the city in dense areas brings us to the need to develop new skills, knowledge and value chains. The paradigm shift is very real: it leads to reconsidering the existing in a spatial as well as temporal approach, and to consider that real estate, which cannot be moved by definition, in motion.