While working with a BIM software it is fundamental to consider, and should be the main requirement, that the users can have plain interoperability, this means the possibility to share the design model data and to be able to work regardless of the software application used, this is, in a really open environment.

IFC is the acronym for Industry Foundation Classes, a data format that has been created to enable this situation, and that allows to exchange an informational model without the loss or distortion of data and information across different applications.  

IFC is, by definition, a standardized open documented digital description of elements of the built environment, for the exchange of data among heterogeneous applications. When referring to the built environment, we are considering any kind of building or civil infrastructure, its construction and maintenance, including the lifecycle of these constructions. The mentioned data is structured as a Building Information Model (BIM) which contains complete details about the referred construction, not only the project plans and specifications, but also the particular design of structural elements, selection of materials, installations, and many other aspects of a construction project, including the schedules to develop all the construction process.

By today, the IFC model specification is an open and available AEC (Architecture, Engineering and Construction) product, registered by the International Organization for Standardization (ISO 16739-1:2018).

The openBIM solution for the building industry

In the last 30 years, the construction design industry has moved from the traditional 2D design methods to virtual 3D design solutions (or BIM solutions) that provide a digital prototype of a project. By today, BIM has firmly established as a de facto standard for the construction sector, being the most popular tool for pre-construction planning, construction and post-construction management. 

But we have to take into consideration that while facing mid-sized to large projects, it’s quite difficult to find that all project participants use the same BIM application. It is at this point where an open approach to BIM takes more relevance.  Here, the implementation of IFC schemas to approach to the collaborative design, construction and operation of buildings has been fundamental. As it was previously mentioned, the main intention of IFC is to provide a neutral platform with an OPEN file specification, avoiding the market preeminence of a specific vendor company that may rule the market.

This platform has been developed by buidingSMART International as a collaborative tool to make possible the interoperability of BIM based projects in the Architecture, Engineering and Construction (AEC) industry.

Industry Foundation Classes allow the different stakeholders to participate in a project, even using their own specific software tools, through a common language that allows transparent open workflows, transparent commercial engagement, comparable service evaluation, assured data quality and at the same time providing long-lasting project data that will be available throughout the life-cycle of the building.

Following buildingSMART appreciations^[1], the IFC schema is a standardized data model that basically describes and codifies:

• Identity and semantics: name, object type, function
• Characteristics or attributes: material, colours thermal properties, etc.
• Relationships: including locations, connections, and ownership
• Objects: doors, columns or slabs, walls
• Abstract concepts: performance, costing
• Processes: installation, assembly, operations
• People: owners, designers, contractors, managers, suppliers, etc.

This schema specification describes clearly how a facility or installation should be used, constructed, and operated. IFC can define the physical components of a building, the manufactured products that will be used in it, the mechanical and electrical systems that will be required for its operation, as well as more abstract structural analysis models, energy analysis models, cost breakdowns, work schedules, etc.

^[1] ©2021 buildingSMART International, Ltd. (https://technical.buildingsmart.org/standards/ifc/)

A building information model captures complete information of a construction project and manages it in a database (including drawings and 3D renderings as views), making it available for use and reuse at any specific point along the development of the project. IFC specifies the representation of these contents of the BIM database in a plain text form, suitable for exchange. The conceptual schema for IFC is defined using the EXPRESS data specification language (ISO 10303-11) that allow an unambiguous data definition and specification. The standard exchange file format for exchanging and sharing data according to the conceptual schema is using this “clear” text encoding of the exchange structure. 

IFC allows to exchange information (geometric and non-design data) from one party to another and amongst different applications that support BIM, but it is not just that, IFC is a means of referencing and archiving project information, whether incrementally during the design, procurement, and construction phases, or as an as-built collection of information for long-term preservation and operations purposes. 

Considering this, the interoperability between software platforms, permits the use of BIM and IFC compatible software across a wide range of hardware devices and interfaces for many different use cases, and not only for private clients as designers, contractors, etc., but also for any kind of public projects. 

The benefits that can be obtained by the implementation of IFC include centralised and visual communication, the integration of different disciplines, early exploration of options and resources, the option to take sustainable decisions, a more efficient design, the site control, as built documentation, etc., effectively developing an asset lifecycle process and model from conception to the final retirement.

One important point to consider is that even if it is technically possible to edit an IFC model, it is not the intended workflow. Almost all software that import IFC treat the model as a referenced copy of the original design. Some tools allow to make minor edits to an IFC model but this is an isolated activity and has no effect on the original design model. In an IFC-based workflow, each discipline remains author and owner of their model content.

Written by Alejandro Adell, from Octopussy