Over the past decade, new documents initiated and drawn up by local authorities, commonly known as "developers' charters", have emerged to provide a framework for the practices of real estate developers (Hervé, 2019). Although the names and content of these charters vary, they share common objectives, notably the regulation of property prices, the improvement of the living environment and the promotion of sustainable development.

The study compares two medium-sized french towns, Montreuil and Tours, which, since the 2020 elections, have been run by a municipality with strong ecological ambitions. Semi-structured interviews were conducted with elected representatives, municipal and inter-municipality technicians, and developers working in the two towns.

The aim is to explore the reasons why the local authorities in these two towns believe that market laws and urban planning documents are insufficient to produce the (ecological) city, and why they are adopting this type of tool, which falls under the heading of soft law (Rode, 2023). What is the purpose of these charters? How are they implemented by local authorities? How important are ecological issues in these charters, in relation to the political colour of the municipalities that adopt them? What are the results?

These developers' charters are a real negotiating tool in the hands of local authorities and, in some respects, a paradigm shift in terms of how the city is made at local level. How are they received and appropriated by developers? Do they see them as constraints and additional costs? Do they play the game of these new local public regulations, adopting cooperative strategies to meet the expectations of elected representatives that go beyond mere legal rules, knowing how important it is for developers to forge solid links and maintain good relations with local elected representatives (Pollard, 2018)?

Key words: Elected representatives, real estate developers, developers' charters, public regulation, city fabric.