ČSN EN ISO 16739

This International Standard is an International Standard for the computer-interpretable representation of construction and facility management information and for the exchange of building data. The objective is to provide a neutral mechanism capable of describing buildings and similar facilities in the built environment throughout their life cycle. This mechanism is suitable not only for neutral file exchange, but also as a basis for implementing and sharing product databases, and as a basis for archiving.
This International Standard is based on the industry standard IFC4 developed by buildingSMART International Limited.
This International Standard defines a set of data schemas using the EXPRESS language for data specification. These schemas, combined into a single computer interpretable schema, represent the IFC data schema used to exchange and share structured building information among various software applications used in the construction and facility management industry sector.
This International Standard includes terms, concepts and data specification items that originate from use within disciplines, trades, and professions of the construction and facility management industry sector. Terms and concepts uses the plain English words, the data items within the data specification follow a naming convention.
- the data item names for EXPRESS types, entities, rules and functions start with the prefix "Ifc" and continue with the English words in CamelCase naming convention (no underscore, first letter in word in upper case);
- the attribute names within an EXPRESS entity follow the CamelCase nameing convention with no prefix;
- the property set definitions that are part of this standard start with the prefix "Pset_" and continue with the English words in CamelCase naming convention;
- the quantity set definitions that are part of this standard start with the prefix "Qto_" and continue with the English words in CamelCase naming convention.
The data schema architecture of this International Standard defines four conceptual layers, each individual schema is assigned to exactly one conceptual layer. Figure 1 shows the schema architecture
1. Resource layer - the lowest layer includes all individual schemas containing resource definitions, those definitions do not include an globally unique identifier and are used depending of a definition declared at a higher layer;
2. Core layer - the next layer includes the kernel schema and the core extenstion schemas, containing the most general entity definitions, all entities defined at the core layer, or above carry a globally unique id and optionally owner and history information;
3. Interoperability layer - the next layer includes schemas containing entity definitions that are specific to a general product, process or resource specialization used across several disciplines, those definitions are typicly utilized for inter-domain exchange and sharing of construction information;
4. Domain layer - the highest layer includes schemas containing entity definitions that are specializations of products, processes or resources specific to a certain discipline, those definitions are typically utilized for intra-domain exchange and sharing of information.