Intermediate-level knowledge is conceptual knowledge that resides between design instances and theories. It supports designers in lateral thinking and facilitates the sharing and communication of specific domain design knowledge. This paper proposes a method for constructing intermediate knowledge to support team knowledge co-creation. We introduce the knowledge construction process through a case study in the context of creative cultural design. In this case study, eleven design patterns were extracted from a collection of 121 design instances. These patterns, serving as typical intermediate knowledge, were transformed into a card-based tool to support designers’ creative ideation. Finally, we evaluated its efficiency and effectiveness in two student projects.