The design team as a subject of the research is a challenge because of complex relations and processes of socialization between members of the team. Because of this, the process of tracking and understanding what is actually happening in the team, how members of the team function and how they participate in the process of product development, is complex. This paper analyses the role and impact of conceptual design and their verbal explanation in the conceptual stage of the construction process. Sketching of concepts serves to create and convey ideas and thoughts that would be impossible to express verbally or textually, and is followed by a verbal explanation which leads to gaining, transferring and exchanging knowledge among project team members In this paper, protocols of five student teams who have to design a solution concept for the given task within a 60-minute session were analysed. The analyses of the protocol was performed by segmenting and coding the sketching activities in programing application ELAN 5.0, so that the collected data could be displayed quantitatively. Quantity and time shares of activities defined by the model of construction-communication framework were analyzed. Apart from the activities, analyses of sketches were also carried out using metric complexity-clarity and Gael's analysis of sketch transformations. The results of the analyses were reviewed and based on them a discussion of the results was made which led to some conclusions, comparing among all five teams in the context of the number of activities and their time share. The results of the research contribute to understanding the role of sketching as an important way of communication between team members in order to improve the efficiency of team work and therefore the entire product development process.