The emergence of Additive Manufacturing (AM) is disrupting design practices to respond to the increased developments of Industry 4.0. However, few designers have sufficient knowledge of AM to use it effectively (possibilities, constraints and limits). Thus, our research objective is the enrichment of the designer in the preliminary phase thanks to the integration of knowledge related to tolerancing by taking the example around the LPBF (Laser Powder Bed Fusion) process. Indeed, this knowledge is necessary to ensure the functionality of the manufactured parts. To do this, we propose to describe these entities using logical concepts (based on mereotopology) as a function of space and time. The AM process seems perfectly suited to this theory because of its layer-by-layer construction. The description will be associated with the skeletons and surfaces of the part or an assembly. It will then be used to analyse and check the consistency of the proposed design with the specifications. This verification will be done through an ontology in which rules will be added as well as a database corresponding to quantitative values associated with geometrical dispersions. The description and the ontology will also be integrated into a global design methodology making it possible to link the knowledge of the designer, the method expert (metrologist) and the manufacturer (AM expert). For example, this enables checking that the functional surfaces of the product comply with the tolerancing for a given specification and a chosen manufacturing orientation. Consequently, the HECATE project will enrich the preliminary design phase with GD&T knowledge related to a given additive manufacturing process.