Design is understood as an ill-defined process, hence no clear operators are defined. Therefore, understanding reasoning in design activity is fundamental for building AI or other design support tools. Design is intentional, purposive and goal-seeking and involves many forms of mental activity, relying on reasoning processes both in individuals and groups. Therefore, studying the role reasoning plays in design is critical to understand how design takes place (Rittel 1987). Roozenburg’s (1993) model for reasoning in design, proposes that innovative abductive reasoning is key in design and required to develop innovative ideas.