The FreeClass Ontology for construction and building materials and services provides classes and properties for describing products and services from the building and construction industry. It is derived from the free classification standard freeClass. For more information, see http://www.freeclass.eu/. The conversion of this ontology has been funded by the Österreichische Forschungsförderungsgesellschaft GmbH (FFG) and the Bundesministerium für Verkehr, Innovation und Technologie (BMVIT) under the FIT-IT Semantic Systems project 'myOntology' (contract number 812515). For describing the commercial aspects of respective offerings, please use the GoodRelations ontology. The FreeClassOWL Ontology is a GoodRelations-compliant ontology for describing construction and building materials and services.