OpenBIM

What is openBIM?

openBIM is a collaborative workflow where project participants exchange Building Information Models using open, non-proprietary standards instead of a single vendor's file format. The term was coined by buildingSMART International (bSI), the standards body behind Industry Foundation Classes. In practice, openBIM means your architect's model, the structural engineer's model, and the MEP consultant's model can all be created in different authoring software, exported to a common format (typically IFC), imported into a Common Data Environment, and checked for conflicts without anyone needing to own a shared software licence.

The core principle is vendor neutrality. No single tool is required; instead, the standards define what data must transfer and how. This is particularly relevant for small practices like solo architecture firms in Slovakia that may work with consultants across different countries, software preferences, and budgets.

How does openBIM differ from traditional BIM workflows?

Traditional BIM often revolves around one authoring platform. The architect designs in Revit, the structural engineer receives the Revit file (or a CAD export), and the MEP consultant either receives the Revit file or works from PDFs and manual coordination. This approach works when all parties use compatible software and versions, but it creates dependency on a single vendor and leaves the client without a format-independent record at project end.

openBIM decouples the workflow from any single tool. Each discipline author works in their preferred software, then exports to IFC at defined coordination milestones. The coordinated IFC model becomes the single source of truth for clash detection, area verification, and handover. At project close, the client receives an IFC model that any free viewer can open, decades after the original software is obsolete.

What standards and formats make up the openBIM ecosystem?

openBIM is not a single tool or file format but a constellation of buildingSMART standards:

IFC (Industry Foundation Classes) is the foundational data schema. Since 2013, IFC has been an ISO standard (ISO 16739). It defines how building elements (walls, doors, beams, MEP components) and their properties are structured so any compliant software can read and write them. Current versions like IFC 4.3 also handle infrastructure data.

BCF (BIM Collaboration Format) is a lightweight XML-based format for communicating issues, comments, and clash results without requiring anyone to open or modify the full IFC model. A structural engineer can flag a clash in the coordinated model, and the architect can respond with corrections in their native tool, then re-export the updated IFC.

IDS (Information Delivery Specification) defines validation rules for IFC files. Instead of saying export IFC and hope it is complete, the project team can define what data must be present in each model (for example, every wall must have a U-value property) and validate exports against those rules before import.

bSDD (buildingSMART Data Dictionary) provides standardized terminology and classification across projects. It ensures that when the architect labels a wall type External Wall - Timber Frame and the energy consultant references it, they are referring to the same definition.

Why should a small architecture practice care about openBIM?

A solo architect's leverage is efficiency and clarity. Traditional workflows often mean chasing consultants for missing data, re-modelling their contributions in your native format, or manually verifying coordination. These tasks are invisible cost drivers that erode margins on residential projects.

openBIM addresses this by making data explicit and exchange automatic. When a structural engineer exports to IFC, you can load their model directly into your coordination environment and run clash detection. When an MEP consultant works from your IFC export, they can flag conflicts using BCF without you needing to re-import their file or make subjective judgements about priority. For passive-house work, consultants can extract thermal properties from your IFC model rather than asking you to fill out spreadsheets by hand.

For solo practitioners in Slovakia collaborating with international consultants (common on EU-funded projects or when sourcing specialist expertise), openBIM removes the friction of software incompatibility. Your tool choice no longer constrains your consultant network.

How does openBIM workflow typically work on a residential project?

A typical scenario: You design a residential building in your chosen BIM tool. At 50% design, you export the architectural model to IFC and send it to the structural engineer and MEP consultant. They import it into their tools, set it as a reference, and model their disciplines. At coordination milestone, they export their models to IFC. All three IFC files (arch, struct, MEP) are loaded into a free Common Data Environment tool or a lightweight viewer. Clash detection runs automatically. Clashes are reported as BCF files with snapshots and comments. You and the engineers review clashes asynchronously, make corrections in your native tools, and re-export IFC. The cycle repeats until coordination is clean.

For handover, you export a final coordinated IFC model to the client and all consultants. This IFC remains the long-term record of design intent and as-built geometry, independent of software obsolescence.

What are common misconceptions about openBIM?

Myth: openBIM requires everyone to use IFC natively. False. You work in your native tool; IFC is the interchange format only at defined points. No one is forced to model directly in IFC or adopt strange workflows.

Myth: openBIM is only for large, complex projects. False. The coordination benefit of openBIM scales down. Even on a small residential project with a structural engineer and MEP consultant, automated clash detection and audit trails save time and reduce error.

Myth: IFC export is straightforward and reliable. Partially false. IFC export quality varies by authoring tool and version. Preparation matters: naming conventions, classification systems, and property mappings must be configured correctly in your tool before export. The first IFC export on a new project often requires troubleshooting, but it becomes routine once standards are established.

Myth: openBIM eliminates the need for drawings. False. Building permits, construction documentation, and specifications still require traditional drawings under Slovak building law. IFC is the coordination and record layer, not a substitute for permit documentation.