The built environment is composed of multiple heterogeneous independent systems that are distributed across multiple levels (e.g., team, project, regional, state, and national) forming its functional hierarchy. The low-level interactions continuously taking place between the connected subsystems in the built environment result in a collective emergent behavior that can be observed only at the upper level. Such behavior can be either desirable or undesirable, significantly impacting various planning and management considerations at different levels within the built environment (i.e., ranging from construction productivity and safety management to infrastructure planning and operations). While the concept of emergent behavior is well known in the field of systems engineering, its consideration remains limited in the built environment-related research and practice. In order to fill this gap, this study aims to develop a taxonomy for emergent behavior in the built environment. It reviews and analyzes existing studies in the construction and infrastructure engineering and management literature where the phenomenon of emergent behavior was acknowledged for the purpose of identifying emergence-related distinguishing patterns. As such, four main types of emergent behavior in the built environment are identified, distinguished based on three principle discriminating features: (i) the nature of underlying interactions, (ii) the level of complexity, and (iii) the boundaries of the information available. The proposed taxonomy is used to guide and facilitate proper modeling, analysis, and quantification of emergent behavior in construction and infrastructure-related contexts. Ultimately, this can serve as a foundation for harnessing the concept of emergence in the planning and management of more optimized and controlled processes in the built environment.