This document discusses an integrated and unified approach for data aspects, specifically for assets in the built environment, using EIF terminology. This document specifies: " a generic Top Level M1: Data model as common form; " a conceptual L1: Data language as common meta-model with four linked data -based concrete language bindings (SKOS, RDFS, OWL and SHACL), including: " a choice of RDF-based formats (to be used for all modelling and language levels); " a set of data modelling patterns (for identification, naming, handling of enumeration types, quantity modelling, asset decomposition, grouping, etc.). " a linking approach for interlinking data sets, interlinking data models and linking data sets and data models which are relevant within the built environment from many perspectives such as: " Building information modelling (BIM); " Geo-spatial information systems (GIS); " Systems engineering (SE) 2); " Monitoring & control (M&C); " Electronic document management (EDM). This document does not specify a knowledge model since this is already available in ISO 12006-3. This document does not specify a meta- data language since this is already provided by the concrete RDF language bindings (being RDFS). The scope of this document in general excludes the following: " Business process modelling; " Software implementation aspects; " Data packaging and transportation/transaction aspects (handled by ISO TC59/SC13 Information container for document delivery (ICDD) respectively various information delivery manual (IDM) / information exchange requirements (EIR)-related initiatives); " Domain-specific (here: built environment-specific) content modelling in the form of concepts, attributes and relations at end-user level (the actual ontologies themselves) beyond a generic upper ontology and modelling patterns.