BCF Markups in OpenBIM Workflow: Collaboration on IFC Models

In the modern process of construction digitalization, the effectiveness of a project is not only measured by the geometric accuracy of the models but by the fluidity with which information flows between the various actors in the supply chain.

In an OpenBIM ecosystem, where interoperability is the fundamental requirement, the IFC standard ensures data solidity, but it is the BCF (BIM Collaboration Format) that represents the true engine of collaboration.

From the technical distinction between the “container” (IFC) and the “message” (BCF), in this article we will analyze the advantages of a lightweight and standardized format capable of drastically reducing errors and resolution times.

Through the examination of best practices for teamwork and the analysis of operational workflows based on cloud platforms and open tools, we will see how BCF is not just a file format but a true methodology to ensure quality, traceability, and success in every BIM project.

BCF Markups in OpenBIM Workflows: Collaboration and Coordination on IFC Models

If the geometric model is the body of the project, communication among stakeholders represents its nervous system. In this context, the BCF (BIM Collaboration Format) emerges as the essential standard for managing coordination in an agile and efficient manner.

The Role of BCF in Multidisciplinary Coordination

Multidisciplinary coordination is not simply the overlap of architectural, structural, and plant models; it is an iterative conflict resolution process. In the past, this exchange occurred through lengthy PDF reports or spreadsheets, often disconnected from the three-dimensional reality of the project.

BCF radically transforms this approach. It acts as a communicative bridge that allows isolating individual issues, documenting them, and transmitting them to team members without having to reload the entire information database. In an OpenBIM workflow, BCF is the enabler that allows the BIM Coordinator to assign specific tasks, tracking their evolution from “Open” to “Resolved.”

Difference Between IFC (Geometry) and BCF (Communication)

To fully understand the effectiveness of an integrated workflow, it is essential to distinguish the two main standards promoted by buildingSMART:

• IFC – is the exchange format for model data. It contains the geometry, properties, and hierarchical structure of the building. Essentially, it is the “snapshot” of the project’s state at a given moment. Modifying an IFC is a heavy operation that requires re-exporting the file.
• BCF – is an XML format (or managed via API) that exclusively carries “messages.” It does not contain geometries but pointers to specific objects within the IFC model. When a user opens a BCF note, the software automatically displays the same view, with the same selected objects and the same camera angle set by the person who identified the inconsistency.

Advantages of the Format: Lightweight, Interoperable, Standardized

The adoption of BCF in professional workflows offers tangible competitive advantages:

• extreme lightweight – since the BCF file contains only text snippets, snapshots (images), and camera coordinates, its weight is just a few Kilobytes. This eliminates the need to exchange heavy coordination files via email or slow servers;
• total interoperability – being an open standard, BCF ensures that an annotation created in a Model Checking software (such as usBIM.clash) can be viewed in other software that can read and interpret that type of information;
• traceability and standardization – each BCF report is equipped with a unique ID, date, author, and priority. This creates an immutable historical record of decisions made during the project phase, drastically reducing ambiguous responsibilities and margins of error on site.

Advantages of the format: lightweight, interoperable, standardized

Best practices for working with BCF markups in teams and different platforms

The effectiveness of BCF markups is directly proportional to the discipline of the project team. Without shared rules, the risk is to generate an abundance of reports that are difficult to manage. Here are the guidelines to optimize coordination.

Standardize the naming convention of issues

To filter and manage hundreds of reports, it is essential that each issue follows a predefined naming convention. An effective title should contain the code of the involved discipline, the area of the building, and a brief description of the error (e.g., [MEP-STR] – Floor 01 – Duct/Beam Interference). This allows the recipient of the report to immediately understand the urgency and scope of the intervention.

Define clear roles, responsibilities, and workflows

In a BIM workflow, not everyone can do everything. It is essential to establish who has the right to:

• open the issue – usually the BIM Coordinator or the person performing the Model Checking;
• assign the task – identify the person responsible for the resolution (e.g., the structural engineer);
• validate and close – once the issue is resolved, it should not be closed by the designer, but by the coordinator after verifying in the updated model.

Create clear and consistent viewpoints

A BCF markup without a good framing is useless. When creating a markup, it is advisable to:

• hide irrelevant elements to focus attention on the problem;
• use colors or transparencies to highlight conflicting components;
• add graphic annotations (arrows, circles) directly on the 2D snapshot attached to the issue.

Always link the issue to specific GUIDs

The true power of BCF markups lies in the dynamic linking. It is necessary and essential that each report is bound to the GUIDs (Globally Unique Identifiers) of the involved IFC objects. This allows the software to automatically select critical elements, avoiding the need for the designer to search for them manually within the model.

Manage versions of the IFC model

BCF issues must always refer to a specific version of the IFC model. For example, if a report is opened on version V.01 and resolved in V.02, it is crucial that the link between the comment and the geometry remains consistent. Using a Common Data Environment (CDE) helps maintain this temporal alignment.

Use platforms with centralized synchronization

Cloud platforms allow for real-time synchronization: as soon as the coordinator detects an error, the designer sees it appear in their software, eliminating the manual sending of files and the risk of working with outdated information.

Document and archive BCF markups in a structured way

At the end of the project, the database of BCF issues represents the project’s “logbook.” Archiving this data in a structured way allows for the analysis of process bottlenecks (e.g., which disciplines generated the most interferences) and provides documentary evidence of the decisions made, useful in case of disputes or for future maintenance of the work.

Best practices for working with BCF markups in teams and different platforms

Recommended workflow: from issue detection to closure

An effective BCF workflow is not just a simple exchange of messages, but a cyclical and structured process that ensures the “closure of the loop” between the detection of an inconsistency and its verified resolution. Without a defined process, the risk is that reports remain in an informational limbo, undermining coordination efforts.

Practical example of workflow

To concretely visualize the usefulness of this approach, let’s analyze the typical case of a clash detected during the execution design phase:

• detection by the BIM Coordinator – during a clash detection session on Model Checking software (e.g. usBIM.checker, Solibri, or Navisworks), it emerges that an air duct intersects a structural beam;
• issue generation – the BIM coordinator creates a BCF annotation. Here, they do not just report the error, but take a snapshot that highlights the involved objects, assigns a high priority, and indicates the MEP designer as responsible;
• communication and upload – the BCF file (or the issue package) is uploaded to the coordination platform or sent to the team;
• takeover by the MEP designer – the designer opens the report with a simple click and, using their BIM Authoring software (e.g. Edificius, Revit, or Archicad), proceeds to resolve the issue;
• resolution and response – the designer, after modifying the duct path, updates the issue status to “Resolved” and adds a comment: for example, “Duct path lowered by 20cm”.
• final validation – the BIM Coordinator receives the notification, uploads the updated IFC model, and verifies that the clash has disappeared. Only at this point is the issue set to “Closed”.

Recommended workflow: from issue detection to closure

Workflow with open and cloud-based tools

The evolution of OpenBIM is shifting the focus towards API (Application Programming Interface) management and Cloud, making coordination a real-time data flow.

• Synchronization via BCF Server – the use of cloud-based platforms (such as usBIM.bcf, BIMcollab, Revizto) allows for the elimination of manual file sending. Authoring software and model checkers connect directly to a central server. Every time a BIM coordinator creates a markup, it instantly appears in the designer’s task list.
• Software independence – in an “open” workflow, the structural team can use one software, the MEP team another, and the coordinator a third. The BCF standard ensures that communication flows without data loss, as it does not rely on the native format of the software, but on its ability to read the coordinates and GUIDs of IFC objects.
• Traceability and governance – cloud platforms maintain the complete history of every discussion. This is crucial not only for efficiency but also for contractual transparency: at any moment, it is possible to trace who requested a change, who executed it, and who approved it, creating a digital record (Audit Trail) essential in complex projects.

FAQ on BCF markups in OpenBIM workflows

What is the role of BCF in multidisciplinary coordination?

The BCF (BIM Collaboration Format) acts as a communication bridge that allows isolating individual issues, documenting them, and transmitting them to team members without having to reload the entire information database. In an OpenBIM workflow, BCF is the enabler that allows the BIM Coordinator to assign specific tasks, tracking their evolution from ‘Open’ to ‘Resolved’.

What is the difference between the IFC standard and the BCF standard?

IFC is the exchange format for model data that contains the geometry, properties, and hierarchical structure of the building; it is the ‘snapshot’ of the project’s status. BCF is an XML format or API-managed that exclusively carries ‘messages’. It does not contain geometries but pointers to specific objects within the IFC model and camera coordinates to automatically display the same view set by the person who identified the inconsistency.

What are the main advantages of the BCF format?

The main advantages are:

1. Extreme lightweight: the file weighs only a few Kilobytes containing only text, snapshots, and coordinates.
2. Total interoperability: being an open standard, it ensures that annotations are viewable in different software.
3. Traceability and standardization: each report has a unique ID, date, author, and priority, creating an immutable historical record of decisions.

What are the best practices for working correctly with BCF?

Guidelines include: standardizing the naming of issues (e.g. [discipline]-[area]-[description]), defining clear roles for opening and closing reports, creating clear viewpoints by hiding irrelevant elements, always linking the issue to the specific GUIDs of IFC objects, managing model versions through CDE, using cloud platforms for centralized synchronization, and storing data in a structured manner.

How does a typical workflow from detection to closure of an issue unfold?

The workflow includes: 1. Identification by the BIM Coordinator (e.g. through clash detection). 2. Generation of the issue with snapshot and assignment of responsibility. 3. Upload to the coordination platform. 4. Taking charge by the designer through BIM Authoring software. 5. Technical resolution and updating the status to ‘Resolved’. 6. Final validation by the BIM Coordinator and setting the issue to ‘Closed’.

What are the benefits of cloud and API-based BCF workflows?

The use of BCF Server and APIs allows for real-time synchronization, eliminating manual file sending. It ensures software independence, as each team can use different tools as long as they read the GUIDs of IFC objects. Additionally, it ensures governance and traceability, maintaining the complete history of every discussion for contractual transparency (Audit Trail).