What is the ISO 16739 standard?

ISO 16739 is the international standard that defines the characteristics of the IFC format for data sharing in a BIM process

The ISO 16739 standard defines the IFC filetype, the open format, non-proprietary and essential format for exchanging dati betyween users that use different software within the same BIM oriented workflow.

So, let’s move on to see what the ISO 16739 actually establishes and what the IFC format is for.

Meanwhile, if you already deal with BIM, or want to view and manage files in the IFC format, we recommend using a BIM management system, simple, powerful and free!

What is ISO 16739?

The ISO 16739:2013 “Industry Foundation Classes (IFC) for data sharing in the construction and facilities management sectors” is an open international standard for BIM data that is exchanged and shared between software applications used by different participants in a construction or facility management project.

In practice, the standard defines:

• a conceptual data scheme;
• an exchange file format for the data that comes into the BIM process workflow.

The processing of an EXPRESS-G and XML computer language of each domain and reference attribute is explicitly defined, specifically defining its description, use and links with other domains. Alternative file formats can also be used, but only if they conform to the conceptual scheme.

At this point it becomes evident that the content of the standard is mainly intended for programmers and developers, but understanding the origin of the data and their characteristics, can also be useful for designers, in order to be able to manage data export correctly towards the IFC format from their originating BIM authoring software.

In fact, legislation expresses all the relationships that BIM objects must have, concerning both their properties and relationships that it creates in association with other objects or systems through (PropertySet) parameters.

Each type of object is identified by PropertySet and QuantitySet, divided by Types and Entity. BIM software is based on these concepts to distinguish the specific parameters of each object from those that identify a type of element common to several objects.

Objects are defined by a specific and hierarchical identification domain, which precisely characterizes each individual object (for example, the IfcDoor domain contains specific attributes for the “port” element) and, more generally, identifies a category of element (for example, the IfcElement domain can characterize an object in its most generic conception).

The following fall within the scope of ISO 16739:2013:

• BIM exchange format definitions required during building life cycle phases
  • demonstrate needs;
  • concept of requirements;
  • outline feasibility;
  • substantial feasibility study and definition of financial authority;
  • outline the conceptual design;
  • complete conceptual design;
  • coordinated design;
  • procurement and full financial authority;
  • production information;
  • construction;
  • operation and maintenance;
• definitions of the BIM exchange format required by the various disciplines involved in the life cycle phases
  • architecture;
  • construction service;
  • structural engineering;
  • sourcing;
  • construction planning;
  • plant management;
  • project management;
  • management of customer needs;
  • building authority for planning permission and approvals;
• definitions of the BIM exchange format including
  • project structure;
  • physical components;
  • spatial components;
  • elements of analysis;
  • processes;
  • resources;
  • controls;
  • professional roles;
  • definition of context.

What is IFC?

We talked about the IFC file, but what exactly is it? What’s it for? Does it really help a designer’s work?

The IFC file is an open, non-proprietary file format and can be used to exchange and share data, during the design, construction, management and maintenance phases, between all the figures and the various applications developed by different software houses without the need for them to support native (proprietary) files.

Designed by buildingSMART International to support interoperability between all building and construction industry professionals working in the AEC sector. The IFC format allows you to produce files that include:

• geometric information of the various entities of “simple” building components (walls, doors, floors, etc.) and all their associated datasets;
• alphanumeric information (property, quantity, classification, etc.) specifying parameters, physical properties, construction information, maintenance information, etc.

To learn more, read the article “IFC file: everything you need to know“.

IFC schema

The IFC scheme can be identified as a storage system for the organisation and transfer of digital data, in order to facilitate interoperability between different subjects.

The IFC defines an integrated model with hundreds of hierarchically organized entities.

There are 3 fundamental concepts on which the IFC logic is based and which represent its structure:

• IfcObjectDefinition – stands for all entities (objects);
• IfcRelationship – summarizes the relationships between entities;
• IfcPropertyDefinition – describes the properties associated with the entities.

IFC Data Schema Composition Diagram

In detail, the IFC schema is a standardized data model that logically encodes:

• identity and semantics (name, machine-readable unique identifier, type of object or function);
• the characteristics or attributes (such as material, colour and thermal properties);
• relationships (including places, connections and properties) between;
  • objects;
  • abstract concepts;
  • processes;
  • people.

A subset of the data schema is called the Model View Definition (MVD). MVDs are subsets of the IFC schema defined by buildingSMART International that group together certain information useful for specific workflows or uses in the building and facility management industry.

Model View Definition

Basically, it represents a filtered view that contains only part of all the information in the entire schema.

Each workflow identifies data exchange requirements for software applications. Conforming software applications must identify the Model View Definition to which they conform.

These views are very useful because they make the data exchange process easier and avoid sharing unnecessary or redundant notions, following standardized procedures.