The problems existent within the built environment are inherently complex due to the interactions between different stakeholders, structures, and systems. The reductionist approach vastly utilized by engineers is not appropriate for dealing with this complexity. Engineers need to be trained to think in systems in order to fully explore the design problem space and therefore identify appropriate design solutions. The study here presented investigates the possibility of the use of concept mapping as an intervention to prime engineering students to think in systems. In the study, 66 engineering students were given two problem framing tasks. Half of the sample received the priming intervention before each task. The control and the intervention group were compared across different metrics. The time spent on the task and length of responses were used as measures of cognitive effort. The number of systems mentioned and the semantic distance between words used in each response were the metrics used for exploration of the design space. Results of the analysis for one of the tasks were significant. The findings suggest that the participants who received the concept mapping priming intervention were able to sustain cognitive effort longer and explore a wider design problem space.