While the projectification of society continues to evolve, it is clearly lagging behind in the public construction sector in Germany. The purpose of the research upon which this article is based was to reveal the role that leadership has on the projectification of the construction sector and to identify the differences between the public and private sectors. Building on the theoretical concept of Institutional Work, semi-structured focus group interviews were conducted on both sides of the construction sector in Germany to ultimately reconcile the findings. The interview’s transcripts were analyzed by applying qualitative content analysis. The responses from the private sector show a very high significance of projects for everyday work and a further trend toward projectification in enterprises. This development is attributable to a positive image of executing projects in the private sector and to the leadership provided. In contrast, projects in the public sector still play a rather subordinate role and tend to be perceived culturally and cognitively as being exceptional. As projects are increasingly important for the public sector, leaders can play a key role in nurturing the necessary cultural and cognitive conditions for projectification. The application of Institutional Work concepts opens promising perspectives for future research in the context of projectification.