What Does Modular Mean? A Systematic Review on Definitions, Ambiguities, and Terminological Gaps in Construction

Abstract

Despite the growing adoption of modular construction (MC) to enhance productivity, sustainability and industrialization in the building sector, critical terminological inconsistencies and conceptual ambiguities persist across academic, professional and regulatory domains. This study conducts a systematic literature review to investigate how the key terms modular, module, modularity, modularization and modular coordination are defined and applied in the recent literature. Following the PRISMA protocol, 85 peer-reviewed articles were selected from an initial pool of 4832 Scopus records. Bibliometric and thematic analyses reveal a lack of conceptual consistency in the application of key terms, most notably the frequent misuse of module to describe non-volumetric components. Beyond identifying these ambiguities, this study maps the most recurrent definitional patterns to outline potential pathways toward conceptual consensus. It clarifies the boundaries between modular (a system attribute), modularization (a design strategy), modularity (a system property), module (a prefabricated, spatially autonomous, functionally complete, and volumetric unit) and modular coordination (a dimensional grid system). Based on these insights, it proposes a conceptual hierarchy, and a set of propositions integrated into a structured glossary that contribute to terminological clarity, foster standardization, and improve communication in the Architecture, Engineering, and Construction (AEC) sector.