With the increasing importance of leadership in project-based organizations, innovation is essential for the sustainable development of construction projects. Since few studies have explored the relationship between leadership and innovation in construction projects, this study fills this research gap and makes a significant theoretical contribution to the existing body of literature. Based on a knowledge-rated and resource-based view, this study aims to investigate various effects of different types of leadership on innovation performance in a construction project-based organization. Therefore, a theoretical model was constructed to explore the mediation mechanism and boundary condition of different types of leadership to improve innovation. The theoretical model was validated with empirical data covering project managers and engineers from the project-based organization in China via regression analysis and path analysis. The results show that transformational leadership and transactional leadership have some positively significant effects on knowledge sharing and innovation performance. Meanwhile, knowledge sharing partially mediates the relationship between transformational leadership and/or transactional leadership and innovation performance. Additionally, by considering different levels of social capital, transformational leadership is likely to have a strong positive impact on innovation performance through knowledge sharing. Our findings ensure a better understanding of the role of leadership, knowledge management, and social capital in the innovation process of construction projects. Therefore, project managers should promote a higher stimulation of a leadership behavior, encouraging knowledge management, and establishing the social capital, thus improving the innovation performance in the project-based organizations in construction projects.

Most studies in the project management field emphasized the effects of leaders or managers, but these effects have rarely been examined at the project level. To cover this research gap, this study applies organizational ambidexterity theory to examine the effects among ambidextrous leadership, ambidextrous culture and sustainability-based project performance. Using a valid sample of 217 project leaders and members from Chinese construction projects, the method of multiple linear regression was adopted to assess the direct relationship among ambidextrous leadership, ambidextrous culture and project performance. Moreover, the bootstrapping technique through structural equation modeling, has been used to analyze the mediating effect of ambidextrous culture. Additionally, the sample data was divided into different groups according to the median value of the variables to conduct the ANOVA and to assess the within-group differences. The results indicated a positive and direct relationship that ambidextrous leadership has on project performance and ambidextrous culture. In addition, there was also a mediating impact of ambidextrous leadership on project performance via ambidextrous culture. Thus, ambidextrous leadership combined with transformational leadership as well as transactional leadership likely has a stronger positive impact on project performance through fostering the adaptive culture and consistent culture. Our findings contribute to an in-depth understanding of the role of the leader and culture for project outcomes. The project-based organization in construction projects could train project leaders’ ambidextrous leadership behavior to facilitate the formation of an ambidextrous culture and to increase project performance. Moreover, this study enriches the existing literature on leadership and project management by highlighting the important path of ambidextrous leadership and ambidextrous culture on the performance at the project level and going beyond the single leadership behavior or single culture.