According to the UN, cities are responsible for 60% to 80% of the world’s annual energy consumption and generate at least 70% of the world’s greenhouse gases. And urbanization is still growing: by 2050, nearly 70% of the world’s population will live in cities compared with 55% today. “Smart cities” aim to optimize the use of resources, in three ways. First, by reducing energy consumption, as in Los Angeles, where smart street lights are said to have cut energy costs by 63%; second, with better energy production, using smart grids, renewable energy and vehicle-to-grid technology; and third, by improving living standards with connected homes, better transport infrastructures, water and waste management. We believe smart cities are now becoming a reality, fuelled by mature technologies such as sensors, fibre/5G networks and software solutions such as Building Information Modelling (BIM) or Building Operating Systems (BOS). These make it possible to design, build and operate infrastructures and buildings with more efficiency and flexibility, enabling smart buildings and facilities management, and eventually ensuring sustainable growth.