The principle of openness is mainly implemented by the following standards:

IDM

Information Delivery Manual – ISO 29481

a standard way to specify the data exchange processes in construction projects

IFD

International Framework for Dictionaries – ISO 12006

a standard way of organizing dictionaries for the construction industry

IFC

Industry Foundation Classes
– ISO 16739

a standard information schema to define data types for construction projects, and in combination with the STEP standards (ISO 10303), a clear text encoding file format for representing data, the so-called IFC SPF (STEP Physical File), a programming interface, the so-called IFC SDAI (Standard Data Access Interface)

The buildingSMART® alliance has also released a series of standards that have not been officially recognized by the International Organization for Standardization, but have found significant acceptance among users and developers of BIM systems. Among them we note

BCF

BIM Collaboration Format

an open file format for logging topics related to IFC data

IDS

Information Delivery Specification

an open file format for representing IFC data requirements, including object sets, naming conventions, attribute value domains, composition relationships. IDS may become the baseline standard for the expected transition to machine-readable standards in construction

bsDD

buildingSMART Data Dictionary

the service and interfaces to access construction data dictionaries, including the IFC schema, international and national classification systems, corporate standards

MVD

Model View Definitions

search queries to retrieve relevant IFC data

OpenCDE

a high-level programming interface for accessing a document repository, organized in accordance with the CDE standard (Common Data Environment - ISO 19650)