Urban Building Regulations-Rue are not prone to predictable rules. They contribute to the development of a strategic urban plan. Their ‘offi cial’ nature makes them particularly sensitive to deep-rooted local habits and this creates tension between inertia and innovation in a process with uncertain outcome, far beyond mere formal approval. The article is in four sections: highlighting the pivotal role undertaken by the Rue in relation to the Psc and the Poc, but especially for sector regulations and additional standards that it tries to coordinate; stressing how the Rue constitutes a ‘schedule’ in the complex equilibrium between surviving and new rules; focusing on the major adjustments that mark the difference with the past; supporting the urgency of renewing effectiveness of regulations, even at the cost of a temporary decrease in effi ciency.
Keywords: Rules; inertia; innovation