Recent research has shown that the increase in a number of participants of construction project elevated the cost and duration of construction. The use of integrated project delivery and the formation of a network organization structure can significantly reduce the costs, as the activities of the participants become more coherent and coordinated. The optimization of decisions is essential for the efficiency of a negotiation process, which in turn depends on the organizational structure. The article specifies three basic types of network organizational structure that can be applied in a construction project: focal (F1), dynamic (F2), multifocal (F3). In this study, a direct assessment of possible effectiveness of each of the three types of network organizational structures was carried out using a vector decision model. For each of the above-mentioned types of organizational structures, the potential effectiveness of negotiating act f0 and the total potential effectiveness F0 was calculated. The results of the study show that the most effective type of network organizational structure is the multifocal collective decisions in which a project manager has several “assistants”.