Nzangi Muimi

What is OpenBIM?

OpenBIM is the use of open standards to create a digital model of construction that contains continuously updated sources of information concerning the project. It is a multidisciplinary process to create and manage the information model of a construction project based on open formats, independent of the software vendor that manages such data.

These open formats include IFC (Industry Foundation Classes) and BCF (BIM Collaboration Format).

Building Information Modelling is about sharing project knowledge in a single dynamic data repository that continually develops during the project’s lifecycle.

Interoperability has been a widely acknowledged problem in the Architecture, Engineering and Construction industry. It originates from the complex and fragmented nature of the industry. Different parties generate project data using different formats and native software files that cannot be appropriately interpreted by others.

How Project Information is Communicated

Typically, a construction project has many stakeholders who produce and consume information produced by others. The execution of a construction project is a series of decisions undertaken based on the project data processed and information supplied by the relevant producers (architects, designers, engineers, quantity surveyors and project managers).

Traditionally, the architect works closely with the client to interpret the client’s brief for a design. He produces a model and published PDF drawings to share with the structural engineers for structural design input, the MEP designers for the development of MEP designs and the quantity surveyors for the performance of quantity take-off and cost calculations.

Consequently, important BIM data is not communicated to these project members when PDF is used. The alternative is to share the native software file with them. This will necessitate these team members to have the same commercial software installed on their computers for them to open and work with the model.

However, designers and architects fear that their model will be altered and changes made to it if they share it in the native software file formats. It is more of a trust issue although it makes a lot of sense.

To solve this problem, the OpenBIM concept was developed. Let us look at it in detail.

The OpenBIM Concept

Graphisoft SE and the Nemetschek Group refer to OpenBIM as a progressive future proof approach to collaboration in the Architecture, Engineering and Construction (AEC) industry.

Further, they argue that this approach is aimed at enabling the barrier-free flow of data along the entire construction lifecycle. It creates seamless and free cooperation among the various disciples in the construction industry, regardless of the software choice.

How does this happen?

It is made possible by the fact that in OpenBIM, project stakeholders are working in BIM with open standards.

OpenBIM Standards and Interoperability

In software terminologies, you might have come across the term “open” somewhere. For example, opensource software. Opensource describes the practice of free software, that is created by a community of members with similar interests. It is free to download, use, share, modify and distribute.

Although the OpenBIM concept is different from the foundations of opensource software, it borrows a few things from that approach.

According to Acca Software, an open data format is a technical specification in the public domain; used for the description and the storage of digital data free from legal restrictions. Also, digital data according to them is defined as open when the syntax, semantics, the operational context and the methods of use are made public accompanied by detailed documentation.

As a result, the data format does not belong to a single software vendor. It is kept in the public domain and anyone can access it and freely build products and services on it.

This is the foundation of OpenBIM standards such as the IFC (Industry Foundation Classes) which is developed and maintained by BuildingSMART. BuildingSMART is an international organization driving the transformation of the Architecture, Engineering and Construction (AEC) industry through the creation and adoption of open international standards.

OpenBIM and the BuildingSMART IFC

While using the OpenBIM workflow, we start creating a building information model using commercial modelling software such as ArchiCAD, Revit or Tekla. In this case, we are working within native file formats such as .PLN (in ArchiCAD) or. RVT (in Revit). To share this with other project members, we will not send them the proprietary file format because they will be able to make changes to our model.

Since we are interested in allowing them to freely view and interact with our model without altering its contents, an open exchange file format is the best to adopt. We can choose to publish our BIM model as an IFC file to share with the rest of the project team. This is the OpenBIM practice.

When a structural engineer receives the IFC file, they will open it using any BIM software they are using. They don’t need to have Revit or ArchiCAD installed on their computer for them to read our IFC model. The challenge of interoperability posed by the differences in preparatory data formats is solved.

Benefits of using IFC to share BIM Models

We have seen IFC, the language for exchanging model information based on the OpenBIM workflow, as a driver of cooperation, collaboration and communication in the construction industry using digital technologies.

The following are the advantages of adopting the IFC and OpenBIM approach:

  1. It supports the transparent open collaboration of all project stakeholders regardless of the software they use.
  2. You can choose who to work with based on the quality of their work and not the software they use. This is possible because of the use of open data exchange formats that are compatible with most BIM software.
  3. OpenBIM creates a common language for widely referenced processes. This allows industry players and governments to procure projects with transparent commercial engagement, easier service evaluation and assured data quality.
  4. It improves the accessibility, usability, management and sustainability of digital data in the construction industry.
  5. OpenBIM together with a seamless digital workflow makes critical project information available to project participants on a timely basis to support decision making through the various phases of the project.

Principles of OpenBIM

The principles of OpenBIM (as stated by BuildingSMART and Graphisoft OpenBIM Community) recognise that:

  1. Interoperability is key to the digital transformation in the built asset industry
  2. Open and neutral standards should be developed to facilitate interoperability
  3. Reliable data exchanges depend on independent quality benchmarks
  4. Collaboration workflows should not be limited by proprietary processes or data formats
  5. The flexibility of choice of technology creates more value for all stakeholders
  6. Sustainability is safeguarded by long term interoperable data standards.


To conclude, we have seen OpenBIM as a building information modelling workflow that promotes sharing of project information in open data exchange formats. It promotes the free flow of project information for decision-making without burdening project members to work with the same commercial software.

Further, I would like to look at it as the introduction of freedom in collaboration and communication of project information. We don’t have to use the same software for us to work together, we can adopt OpenBIM digital workflows and share project data using the IFC format.

Also, it is a progressive approach because it mandates BIM software vendors to continuously improve their products in the search for a competitive edge.

Given that the problem of interoperability is solved by adopting an open data sharing and exchange workflow, the Architecture, Engineering and Construction (AEC) industry stand to gain lots of benefits. Fragmentation will no longer hinder us from working together as a team. The barrier that remains is our mindsets. With a positive mindset shift, project teams will realise huge efficiencies, time savings and seamless workflows aided by construction digital technologies.

Consequently, construction projects will save on time and costs as reworks and errors resulting from technicalities or communication inefficiencies will reduce. In the end, more value will be realised for the client’s money; with more and more projects becoming successful.

Let me know what thoughts you have on this OpenBIM workflow and the potential it has for the construction industry. If you are already implementing this in your organisation and projects, have you realised its benefits yet? Share your experience with this blog.

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