Building Design

BIM Is Becoming More Difficult

7 Mar, 2017 By: Robert Green

CAD Manager Column: Paradoxically, as building information modeling (BIM) becomes more commonplace, it’s not getting any easier — it’s just the opposite.

It's a simple rule: The more you do something, the easier it becomes. Well, maybe that’s the rule for most things, but not for building information modeling (BIM). Now that BIM has become an expectation on many design projects and more parties are drawn into it, the process is getting more challenging, not less. In this edition of the CAD Manager’s Newsletter, we’ll flesh out some of the increasingly complex issues I’m asked about by a variety of CAD and BIM managers. Here goes.

Complicating Factors

So why is BIM getting harder? Here are the complaints I hear most often, along with some background information:

It’s no longer limited to the building and the core systems. Five years ago, a building with the basic mechanical, electrical, and plumbing (MEP) discipline systems placed inside it would have been considered a completed BIM project. Now the expectation is to include many more elements, such as fire protection systems, electrical schematic integration, energy analysis, tie-ins to geographic information system (GIS) data for utilities location and water runoff analysis, interior building components (including machinery and office layouts), etc.

The magnitude of the projects has grown. Higher-powered workstations and server architecture software tools are allowing much larger projects to be tackled in BIM than just a few years ago. The expanded size and scope of the projects brings us to our next problem …

Big projects require larger, more specialized staffs. The inclusion of additional disciplines and systems means that more specialized design talent will be used on the project. Many times these specialized contributors may be outside resources — think structural or MEP contractors — and all these laborers will have their own preferred software tools that must be coordinated with the master BIM project.

Nobody is quite sure how to fit it all together. Ask an executive from Autodesk or Bentley Systems how they propose you handle all these complexities, and you won’t receive a complete answer. The reality is that the software vendors are struggling with how to get all this stuff coordinated, just like we are.



Network infrastructures are far more complex. Even if you can solve all the coordination issues and make all the software work together in theory, getting it to work in the real world with multiple cloud providers, sluggish WAN connections, and varying security policies make the IT part of BIM a real headache.

Management doesn’t get it. Now that senior management teams have heard the word BIM for a few years, they think it’s a familiar technology that’s as simple as running a CAD application, so they don’t worry about it anymore. This lack of understanding often means that BIM coordination isn’t included in customer or vendor contracts, so the CAD or BIM manager ends up dealing with it.

Where Is It All Leading?

So what can we conclude from these increasingly difficult problems? Here are the consensus conclusions many of my clients have come to over the years, listed in an order that makes the most sense for most companies:

Clash detection is the best thing BIM brings to the table. Sure, it’s cool to have takeoffs and material lists for purchasing, and to have all the information about a building after it is complete, but the best benefit of BIM is eliminating construction timeframe clashes before they happen. Therefore, getting everything into a consistent format to check for system clashes becomes the Holy Grail of any BIM project.

No single BIM tool can do it all. But as software companies try to get everything into a single package to facilitate clash detection, it becomes increasingly clear that no BIM software tool can do it all. The fact is that executing large-scope BIM projects requires a patchwork of software, and a robust set of best practices and standards to make them work together.

But interoperability between software products is sorely lacking. Imagine creating a BIM model of something like a semiconductor chip manufacturing plant that uses building components from Revit, MEP and structural components from Revit add-ons, gas handling schematics, separate gas handling trays, safety drawings and P&IDs for evacuation plans, equipment modeled in SolidWorks, exhaust gas handling plenums for equipment hookups, fire protection systems, electrical controls, etc. In these examples alone we could encounter RVT, SLD, DWG, XLS, MDB, and PDF files to manage BIM, parts, drawings, spreadsheets, databases, and non-editable output, respectively. How in the world can all these be linked together?

Coordination of disciplines creates a software need. Due to the lack of interoperability associated with all these software products, BIM managers must use Swiss Army knife–style tools such as Navisworks to pull together all the diverse file types required to execute a BIM project. In many ways, the success of the BIM project is driven more by how the various files are coordinated than anything else.

Keeping it all in sync is a big problem. With all the players, file types, and disciplines located in multiple offices with varying degrees of network connectivity/speed between them, keeping everybody on the right set of files is problematic. In many firms, IT departments are an integral part of BIM execution, because server synchronization and bandwidth optimization are crucial.

Action Items

So now that you have a list of potential problems, how should you approach the difficulties of the growing scope of BIM? Here are my recommendations, in order of importance:

Make sure your boss and IT grasp the problem. If they don’t, you’ll never get the authority and budget to deal with the issues, so this is priority one!

Fight for a seat at the project table. Do not let large-scale BIM projects get started without being involved in the planning. Strive to be a constructive member of the project team who seeks to optimize BIM execution. Stress that by making smart choices now, your company will save time later.

Know your formats. You must know which file formats your customers need to receive and your vendors will use, and have all the software versions identified. It is hard enough to control all these issues without having to guess about file versions and formats. Note: Having a seat at the project table will help greatly!

Benchmark file coordination. Will all these file formats actually work? Can you meet the client demands? How will software versions change over the course of the project? If you don’t know these answers going into a project, you’re likely to preside over a train wreck later so test, test, and test some more. If you don’t see it work, assume it doesn’t.

Don’t get bullied into accepting unknown software. Unless you understand and have tested the software in question, do not allow it to be used on your project. As the CAD/BIM manager, you’ll be responsible for it in the end, so you’re totally within your rights to veto anything that could be problematic.

Get everything in the contracts. Define all the file formats, versions, and deliverables in all project contracts so there is no doubt about the specifics. This way if things change later your company can charge extra for additional tasks, and you won’t have to fix anything submitted incorrectly by subcontractors.

Summing Up

It all seemed so simple when BIM started: We’d learn some new 3D software and design buildings, and 2D CAD problems would give way to a nirvana of automated clash detection. But like so many things in the software world, the reality hasn’t been as easy as the demo led us to believe. And now CAD and BIM managers everywhere are figuring out how to cobble it all together.

What’s your take on the increasingly complex nature of BIM software and project management? I’d love to get your input for an upcoming edition of the newsletter. Please send me your thoughts at Until next time.

About the Author: Robert Green

Robert Green

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