In collaborative design projects, designers are required to share and identify design knowledge, which is an aspect of design that can benefit significantly from formalisation of design knowledge. On the other hand, working with formalised design knowledge should not impede the creativity in design by restricting the design process and limiting the freedom of manipulating design information. The research project reported in this article provides an approach to design modelling that manifests a high level of flexibility and extensibility of the formalised design knowledge. The design process is supported in this approach by tools that help identify the design rationale through type recognition and by Internet-based services that allow designers to share design models and design knowledge in a well-structured manne
