Regulations and standards
Rainwater harvesting and use in urban buildings

As already mentioned, the use of rainwater is a very old practice that varies from country to country. It existed and developed long before the emergence of a regulatory framework or even guidelines. This predominance of practice over standard (understood here as "the set of formalized provisions and procedures designed to define, or even frame, said practice") remains the reality in many countries today. In this section, it is not possible to provide an international overview of the regulatory and/or normative situation. We shall therefore focus on the French case and its specific features. We begin with a presentation of the French regulatory texts themselves (§ 2.1