Revisions and modifications: the effect of change on French plans d'occupation des sols

Ensuring certainty in planning policy at the same time as allowing for flexibility to meet unforeseen circumstances is an issue that confronts all planning systems. The problem is particularly acute in those systems, such as the French, which place a high premium on legal certainty by using zoning and regulations as the main means of control. Inevitably there are various means by which the rules may be circumvented.This paper is about the use of formal mechanisms to modify and revise <I>plans d'occupation des sols </I>(POSs; local land-use plans) in force. These procedures have caused some concern because of the frequency of their use, in particular in the conurbation of Lyon. The paper presents a study of the frequency of changes to POSs in Lyon and the content of those changes in the eastern sector of the conurbation.The conclusions drawn from the study are that frequent changes are problematic both for the ability to maintain strategic policy and for the accountability of decisionmaking. An enhanced role for <I>enquêtes publiques </I>(public enquiries) would help. Attention also needs to be given to the way in which regulations are framed. Where necessary, they should recognise the possibility of choice.