• Renewing the legitimacy of political action via the sustainability requirement. How does sustainable development renew attitudes, tests and practices for justifying action, especially public action? What are the criteria for justice in the way changes are made and in the redistribution of profit and loss?
• Integration of non-public actors, especially those from civil society, in the design of public policies and, consequently, in the co-construction of the city.

It is therefore important to take into account differences in political culture, but also changes in lifestyles (see Study: Outlook on lifestyles in 2050 and factor 4).