Building related data tends to be generated, used and retained in a domain-specific manner. The lack of interoperability between data domains in the architecture, engineering and construction (AEC) industry inhibits the cross-domain use of data at an enterprise level. Semantic web technologies provide a possible solution to some of the noted interoperability issues. Traditional methods of information capture fail to take into account the wealth of soft information available throughout a building. Several sources of information are not included in performance assessment frameworks, including social media, occupant communication, mobile communication devices, occupancy patterns, human resource allocations and financial information. The paper suggests that improved data interoperability can aid the integration of untapped silos of information into existing structured performance measurement frameworks, leading to greater awareness of stakeholder concerns and building performance. An initial study of how building-related data can be published following semantic web principles and integrated with other ‘soft-data’ sources in a crossdomain manner is presented. The paper goes on to illustrate how data sources from outside the building operation domain can be used to supplement existing sources. Future work will include the creation of a semantic web based performance framework platform for building performance optimisation.