If you’ve ever stared at a building model in Revit or another program and thought, “This would be easier with pencil and paper”, congratulations—you’ve already experienced the bittersweet charm of BIM. And now, dear reader, we’re stepping into the world of openBIM, where the expectations are high, the acronyms endless, and the coffee breaks never long enough. This is the first in a series of posts where we will try to unpack the mysterious (and occasionally frustrating) world of BIM standards. ☕📊🛠️

The Roots of openBIM

openBIM is basically the rebellious teenager of the construction industry. Back in the 1990s, when CAD was still king, a group of engineers and software vendors realised that everyone was speaking a different “digital language.” One software couldn’t talk to another, and project teams were stuck in data silos. And this is how buildingSMART International was born, which started its life as the International Alliance for Interoperability (IAI). Its mission? To create a universal way for construction data to move around freely without getting lost in translation. Thus, openBIM was born: a software-neutral approach where collaboration is supposed to be the rule — at least in theory. 🤝🔑📡

The Evolution of IFC: A Never-Ending Story

At the heart of openBIM lies IFC (Industry Foundation Classes), the data model designed to let software talk to each other. The first IFC file ever exported came from Allplan in the late 1990s. 🖥️📀📂

Since then, IFC has gone through versions that sound more like rocket launches than standards: IFC1.0, IFC2x, IFC2x3, IFC4, IFC4.3, and now there are whispers for the upcoming IFC5. Each promised to solve interoperability forever. Spoiler: they didn’t. Still, IFC2x3 became the workhorse everyone grudgingly relies on, while IFC4.3 is the shiny new model that includes infrastructure (rail, roads, bridges). The future? Relational structures reached their limits when hierarchies need to be changed or new aspects added. Although this is possible in principle, it is often very time-consuming. A move from the traditional STEP file-based exchange format toward graph-based data models seems inevitable. These would allow faster queries, easier linking between different kinds of data, and stronger support for Digital Twins. Instead of rigid file dumps, imagine a living network of information where components—like your bridge and your tunnel—are connected as relationships in a graph database. 🌉🤖📲

BIM as a Model and a Process

BIM isn’t just a 3D model; it’s both a model (digital representation of an asset) and the processes that create, share, and use that data. According to ISO 19650, it’s about having one reliable source of truth so people stop emailing 43 different versions of the same floor plan. The model holds geometry and alphanumeric data (think material, location, cost). The process? That’s the long, painful journey of making sure everyone actually uses the data correctly. 📊📧🔧

On top of that, BIM isn’t stuck in just three dimensions, it is a multidimensional beast: 3D for geometry, 4D for time (think schedules and sequencing), 5D for cost, 6D for sustainability and energy, and even 7D for facility management. Each extra “D” promises more insight but also adds more complexity—because why stop at 3D when you can juggle 7D and a migraine at the same time? 🎲⏱️💸🌱🏢

Why Digitalisation Matters in Construction

Construction used to be one of the least digitalised sectors (yes, even farmers with tractors had more tech). BIM and digitalisation bring huge benefits: 🏗️💻📉

• Cost reduction (fewer mistakes = fewer lawsuits).
• Transparency (no more “lost” Excel sheets).
• Efficiency (less waiting around for updated drawings).
• Sustainability (waste less, build smarter).
• Better communication (arguing over models instead of napkin sketches).
• And yes, you might finally impress that client who keeps asking about “digital twins.”

What BIM Brings to a Company

Introducing BIM in your company is like upgrading from a trusty old car to a sleek electric vehicle — it feels promising and efficient, but it takes time to adapt before it becomes second nature. Productivity dips initially, because staff need training, workflows must change, and contracts get rewritten. But once the dust settles, you gain: 🛠️💡📊

• Control: Better project oversight.
• Transparency: Everyone sees the same data.
• Reputation: Clients like working with “modern” companies.
• Savings: Less rework, more efficiency. In short, short-term pain for long-term gain.

Technical Aspects of openBIM (Acronym Soup Edition)

Here’s the dreaded acronym soup (with examples to keep you sane): 🏷️🔤📂

• IFC Data Schema: Think of it as the grammar of BIM — how objects and attributes are structured so all software speaks the same language. Example: a door isn’t just a rectangle; it’s an object with height, width, material, and fire rating.
• bSDD (buildingSMART Data Dictionary): A multilingual dictionary for building components. Example: whether you call it Fenster, window, or fenêtre, the bSDD ensures we all mean the same thing.
• MVD (Model View Definition): No one needs the entire IFC model all the time. MVDs are subsets tailored to specific tasks. Example: the “Coordination View” only includes geometry and basic properties needed for clash detection.
• IDS (Information Delivery Specification): Think of it as the shopping list for data. Example: “For this project, every window must include U-value, fire rating, and manufacturer.”
• BCF (BIM Collaboration Format): The sticky notes of BIM. Instead of emailing screenshots, you pin a comment to the model: “Hey, this wall collides with the HVAC duct. Fix it.”

openBIM Collaboration: Big vs. Little, Closed vs. Open

Collaboration is where theory meets reality. Let’s break it down: 🔧🗂️🤝

• Little BIM: BIM used inside one company. Everyone’s happy… until you need to collaborate with outsiders.
• Big BIM: Full project-wide collaboration across organizations. Much harder, but much more rewarding.
• closedBIM: Everyone uses the same software. Simple, but limiting.
• openBIM: Different software, same data standards (via IFC, bSDD, etc.). Harder to achieve, but the holy grail.

Here’s how these collaboration approaches usually play out in practice: 📝📊🖼️

• closedBIM: Works smoothly when everyone uses the same software, but breaks down once other tools join the mix.
• openBIM: Enables interoperability across platforms, though it can bring setup challenges and standardisation headaches.
• Hybrid models: Combine both—closed collaboration inside companies and open standards between them, with benefits and drawbacks from each approach.

And then come the BIM requirements: clear roles, clear deliverables, clear responsibilities. In other words: make sure someone actually knows who’s doing what, or chaos reigns. 📌📑⚠️

BIM Standardisation in Switzerland

In Switzerland, BIM standardisation follows the SN EN ISO 19650 series, which sets out the international framework for managing information over the entire lifecycle of a built asset. Section 3.1.4 of the handbook highlights how these standards are being implemented nationally, ensuring consistency and clarity for Swiss projects. For companies and professionals working in Switzerland, aligning with this standard is essential to stay compatible with international practices while also fulfilling local requirements.

You can explore and purchase the standards directly from the SIA (Swiss Society of Engineers and Architects) here: SIA Shop – ISO 19650. 📘🔗🇨🇭

Final Thoughts

openBIM is like conducting an orchestra 🎻🥁🎺: every musician shows up with a different instrument and their own sheet music. At first, the result can be chaotic — clashing notes, lack of coordination, and plenty of frustration. But once everyone tunes in and follows the instruction of the conductor, the music becomes harmonious and powerful. That’s exactly how openBIM looks like: confusing at first, full of competing inputs, but ultimately leading to a coordinated and worthwhile result. It promises better collaboration, smarter workflows, and fewer sleepless nights. Just don’t expect it to be easy. After all, if it were simple, we wouldn’t need handbooks, standards, and entire blog series to explain it.

👉 Stay tuned for the next post, where we’ll dive deeper into the weird and wonderful world of IFC and its many personalities. Spoiler: it’s less about classes and more about avoiding clashes. 🎬📖🔍

💬 Have you wrestled with BIM or openBIM in your own projects? Share your stories, frustrations, or small victories in the comments — I’d love to hear your stories, lessons learned, or tips on how you’re surviving in the era of digitalisation in construction — so don’t be shy, share them in the comments below!