Open BIM vs Proprietary BIM: Which Strategy for Your Project and the IFC Format
IFC BIM: openBIM vs proprietary BIM compared, with benefits, limits and strategic choices for your project, whether public or private procurement.
💡 In brief
BIM comes in two competing approaches: openBIM, based on the open IFC format standardized by buildingSMART (ISO 16739), and proprietary BIM, confined to a single vendor’s ecosystem. openBIM guarantees interoperability, longevity and data sovereignty. Proprietary BIM offers integrated features, but creates dependency. For public procurement and long-term projects, the openBIM approach is the way to go. Kroqi, an openBIM platform backed by the CSTB and hosted in France, supports this strategy.
Choosing between openBIM and proprietary BIM commits your project for ten to fifty years. It is a data governance decision, not a simple choice of tools. The IFC format, an open standard defined by buildingSMART, is at the heart of this shift. This article sets out the benefits and limits of both approaches, the impact on French public procurement, the decision criteria and the conditions for successful implementation. A French openBIM platform backed by the CSTB supports the stakeholders who choose openness.
What is BIM and what distinguishes open from proprietary
Working definition of the two approaches
BIM (Building Information Modeling) refers to a collaborative methodology for the design, construction and operation of buildings, based on the digital model. This methodology can be applied in two distinct ways.
openBIM rests on a principle of open data. Models circulate between stakeholders in the IFC format, regardless of the software used to produce them. The promise is clear: no one is locked into a particular vendor.
Proprietary BIM confines the model within a single vendor’s ecosystem. Files are in the native format of the software suite, optimized for internal use but difficult to use outside that environment. The complete guide to understanding BIM in construction details these underlying principles.
IFC, the pivotal format of openBIM
IFC, short for Industry Foundation Classes, is the pivotal format of openBIM. It describes the geometry of a building and the properties of its building elements (walls, windows, equipment) in a way that any compatible tool can read.
IFC is standardized by buildingSMART, a non-profit international organization, and has held ISO 16739 status since 2013. This standardization guarantees the stability and longevity of the format, independently of commercial vendors.
What are the concrete benefits of openBIM
Interoperability between industry software
Interoperability is the central benefit. On a project, the architect, the structural engineer and the MEP engineering office often use different software. IFC lets each of them read the others’ contributions without changing tools.
This independence from vendors changes the dynamics of the project. The project owner can view the consolidated model without having to install or purchase a specific license. A platform natively connected to the BIM tools on the market amplifies this openness by making IFC imports and exports easier between all participants.
Longevity and life cycle
A building lasts fifty to a hundred years. The digital model must remain readable for just as long. With an open, standardized format, this longevity is ensured by the international standard, regardless of the commercial fate of the vendors.
Continuity across the design, construction and then operation phases is also better ensured. The operator who takes over from the builders can access the model without depending on software inherited from the project. This continuity is explicitly expected by the ISO 19650 standard.
What are the benefits and limits of proprietary BIM
Operational benefits of an integrated ecosystem
Proprietary BIM offers real benefits that it would be dishonest to ignore. Native performance in the original software is generally superior: no conversion, no loss of information during internal operations.
Integration between modules of the same vendor suite smooths internal workflows: an architect who moves from modeling to rendering and then to energy analysis stays within the same universe. Some advanced features appear first in proprietary ecosystems before being standardized in IFC.
The table below summarizes the strengths and weaknesses of the two approaches against the strategic criteria.
| Criterion | openBIM | Proprietary BIM |
|---|---|---|
| Reference format | IFC (open, ISO 16739) | A vendor’s native format (.rvt, .nwd, etc.) |
| Interoperability | Read and exchanged by any compatible tool | Limited to the vendor’s ecosystem |
| Long-term longevity | Readability guaranteed by an international standard | Dependent on the vendor’s survival |
| Public procurement | Compliant with ISO 19650 requirements | Risk of locking in the contracting authority |
| Data sovereignty | Possible with sovereign hosting | Often tied to a non-European vendor cloud |
| Total cost of ownership | Flexible licenses, free viewer possible | Vendor licenses, cost rising over the long term |
Strategic limits of a proprietary approach
The main limit is vendor dependency (lock-in through the ecosystem). Once a project is committed to a proprietary ecosystem, the cost of migration becomes prohibitive. The project owner loses bargaining power on license renewals.
Loss of information when exporting to open formats is another limit. Not every native function translates perfectly into IFC. Those who receive the model inherit a degraded version, which can lead to misunderstandings and technical trade-offs during the project.
The long-term cost of licenses is the third angle. Annual subscription models, now the norm, turn ownership into perpetual rental. Over the life of a building project, the bill becomes significant.
What is the impact on French public procurement and public contracts
openBIM requirements in public procurement
French public procurement increasingly refers to the ISO 19650 standard in the CCTP. This reference generally implies the use of open formats and the production of IFC deliverables at each contractual milestone.
Digital sovereignty of project data is the other rising requirement. The data of a public building, particularly a sensitive one, should not be hosted on infrastructure subject to the Cloud Act or the Patriot Act.
Risks of a proprietary strategy in public procurement
Imposing a proprietary format in public procurement exposes you to several risks. The difficulty of comparing bids is immediate: only bidders equipped with the mandated software can respond, which restricts competition.
The lock-in of the project owner to the selected vendor is the other major risk. In the long term, operation and any later renovations remain trapped in that ecosystem, with the associated license costs.
Finally, costly rework during the operation phase often occurs: if the operator does not use the same software as the designers, the model must be converted or rebuilt, with a loss of reliability.
How to choose between openBIM and proprietary BIM for your project
Criteria by project type
The right choice depends on the concrete context of the project:
- Single operation vs multi-year portfolio: a social landlord or local authority overseeing several operations over time has every interest in favoring openBIM to share practices and tools.
- Simple private contract vs complex public contract: a public contract will increasingly require openBIM. A simple private contract can make do with a proprietary ecosystem if all the stakeholders belong to it.
- New build vs renovation of existing assets: renovation operations generally involve several heterogeneous participants, which argues for openBIM.
Criteria by stakeholders and life cycle duration
The number of participants involved in the model is a decisive factor. The more numerous and diverse the stakeholders (architect, several engineering offices, quantity surveyor, OPC, contractors, operator), the more relevant openBIM becomes. For architecture firms that work with a variety of technical partners, openBIM is the only truly workable choice.
The planned retention and operating period also matters. For a building meant to serve for fifty years, betting on the longevity of a particular vendor becomes risky.
Finally, the level of sovereignty required (GDPR, NIS2, sensitive sectors such as healthcare or defense) often tips the decision in favor of a French openBIM platform.
How to implement a successful openBIM strategy
IFC-compatible tools and platforms
An openBIM strategy relies on several building blocks. An online IFC viewer accessible without industry software opens the model to all participants, including those who do not do any modeling. A collaborative platform compatible with IFC and BCF centralizes exchanges and annotations.
The common data environment (CDE) compliant with the ISO 19650 standard structures document flow. Models, drawings, meeting minutes and approvals are versioned and tracked there.
Good practices for exchange and governance
The project’s BIM execution plan (BEP) specifies the IFC exports expected at each milestone: required level of information, properties to include, quality checks. Without this clear agreement, openBIM degrades in practice.
The level of information need (LOD) for each milestone (sketch, preliminary design, detailed design, construction, DOE, operation) must be defined from the outset. Each IFC export is then checked against this expected level.
Finally, traceability of revisions and statuses secures the whole chain. An IFC deliverable carries a version, a document status (in progress, shared, published), an identified author and a timestamp. This discipline turns openBIM into a robust professional practice, and not a mere intention of openness.
The choice between openBIM and proprietary BIM is not just a technical debate. It commits data sovereignty, the longevity of the investment and the project owner’s freedom of action over several decades. For French public procurement and long-term projects, the openBIM approach is the obvious strategic choice. The tools and platforms exist to implement it today, within a French framework and in compliance with current standards.
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