The construction industry is characterized by fragmentation due to the distinct phases, as well as the complex structure of the industry itself. The numerous processes involve diverse stakeholders each requiring seamless integration through the accurate transfer of information to maintain its integrity. Different information models both those defined by standards and industry-specific, complicate the choice of models to adopt, impacting interoperability. This research aims to develop a methodology to address this issue by unifying existing ontologies developed for different information models. The approach combines elements of the Modular Ontology Modelling methodology, and the Level of Information Need (LOIN). This methodology is currently being evaluated in collaboration with multiple companies in the Swedish AEC industry as part of an ongoing project. Results suggest using standardized machine-readable data templates, industry accepted data dictionaries and ontologies based on standards enable unambiguous exchange of information along the value chain of a construction project.