The knowledge building can be seen as a collaborative process of which negotiation is a fundamental aspect. The use of technology to support this process has been attempted in various groupware systems. However, there is no adequate support system for the process of negotiation, which generally relies on voting as the element for reaching agreement in decision-making. On the other hand, the best approaches to this problem have been formalised in learning environments where there is a clear hierarchical structure. When the environment is not hierarchical, new problems arise which require special attention. This article presents a model of knowledge building that has negotiation as its basis in a group that is non-hierarchical in its structure. 'Me model is implemented on a prototype tool named ShaKnoMa, which is tested on common tasks in an environment such as that proposed here. For the knowledge representation, concept maps are used which act a scaffolding to classify, index and search the information