In this paper, we present a new generic method for an interactive interpretation of sketches to avoid a fastidious verification phase. After a preprocessing phase in which we extract a set of primitives, the interpretation process consists of an interactive analysis. The analyzer is based on a competitive breadth-first exploration of the analysis tree. As opposed to well known structural approaches, this method allows to evaluate simultaneously several possible hypotheses of recognition in a dynamic local context of document. The decision process is able to solicit the user in the case of strong ambiguity: when it is not sure to make the right decision. The user explicitly validates the right decision. While, in practice these approaches often induce a large combinatorics, this paper presents optimization strategies to reduce the combinatory. The goal of these optimizations is to have time analysis compatible with user expectations. These strategies have been integrated into both preprocessing and analysis phases. To validate this interactive analysis method, several experiments are reported in this paper on off-line handwritten 2D 24 architectural floor plans.