Motivation drives our behavior that leads to performance and achievement of targets. Especially in collaborative delivery systems, the motivation within a group is sensitive to the project conditions and relationships within the team. However, research on motivation is underrepresented in construction and is mainly based on the simplified classification into intrinsic and extrinsic motivation. This concept is obsolete. In recent decades the self-determination theory (SDT) developed by Deci and Ryan has spread within the motivation and organizational theory. SDT defines motivation based on the three psychological needs, (1) autonomy, (2) competence, and (3) relatedness, and divides extrinsic motivation according to the degree of autonomy. Since the theory has not been transferred to the construction industry, this paper applies existing scales to give – based on a particular case – a first indication regarding the following question: What drives project team members in the construction industry? Therefore, one year after 21 interviews with one project team were conducted, a survey was sent to the interviewees (90% response rate), now working on different projects in different project teams. It was found that autonomous motivation drives the selected participants. Furthermore, the data shows that good relationships as well as the feeling of competence regarding their task are important and need to be considered when developing the project settings.