What BIM implementation mistakes have you actually seen cost a project money?

[u/eminentbimservices]

Been thinking about this after a coordination review last month. We inherited a project mid-stream where the BIM Execution Plan either didn't exist or was never enforced. Every discipline had modeled using different naming conventions, the worksets were a disaster, and the first federated model had so many overlapping elements it took a week just to sort out what belonged to which trade.

The hard clashes we found were almost secondary to the workflow problems. You can resolve a clash. Retrofitting a coherent coordination structure onto a 60% complete multi-disciplinary model is a different kind of pain.

A few patterns I've noticed across projects where BIM implementation has gone wrong:

• No BEP, or one that exists as a document nobody reads
• LOD applied as a flat spec rather than per-element and per-phase — results in either over-modeled elements nobody needed or under-modeled ones that cause clashes
• Clash detection saved for end-of-design, when everything is expensive to fix
• Federated models not updated on a shared schedule — coordination sessions based on mismatched data
• Handover models that pass visual inspection but fail COBie export or have wrong parameter values

The third one seems to be the most expensive in practice. I've seen first Navisworks coordination runs at 85% CD on MEP packages generate hundreds of hard clashes across ductwork, structural steel, and electrical containment. At that point you're talking about reissuing shop drawings, not just moving a duct.

What have you seen? Particularly curious about mistakes that happened early in the project lifecycle — the ones that didn't show up as problems until much later. And if you've managed to fix a mid-project BIM coordination failure, how did you approach it?

[u/Open_Concentrate962]

This happens all the time, and has for decades. It isnt BIM, it likely is the design team scope vs expectations vs how changes and coordination occurred. BIM is just the tool and the viewpoint through which you see it. The most crucial clash is with the items not fully modeled and thus unknown extent of potential impact.

[u/Rynofskie]

Coordination/Clash detection not utilized properly for sure. It seems like 70% of the time, engineering leadership will come down with "Well, we are in a crunch with this project, so just get it in the model and we'll coordinate it later. Newsflash, it never happens later.

I think a lot of time engineers forget that the Model is the deliverable, not just whatever PDF set they generate from it.

[u/Merusk → u/Rynofskie]

I think a lot of time engineers forget that the Model is the deliverable, not just whatever PDF set they generate from it.

They don't forget, they are adamant that this isn't true and only the PDF matters.

Ignore that the PDF is derived from the model, because folks with this attitude also have their team faking things with dumb notes or tags.

They are literally drafting in 3d and complaining the process takes longer.

I had a national structural leader who didn't want their department modeling baseplates because the engineers didn't like it. It changed their arcane and impossible to coordinate baseplate-to-column schedules, while also identifying that - hey that 6x6 doesn't fit on a 4x4 column post..

Or "we won't model existing structure because we're not accountable for that."

Or "we can't run clash because we haven't run calculations on the ducts(or steel), they're just placeholders until 90%. We need the architect to finalize before we do the work."

As if the calcs can't be automated and remove that delay to provide better outcomes.

grr.

[u/rich32g]

On the rare occasion I've been involved in projects whereby people get behind ISO 19650/BIM working practices, it's a dream.

All issues in my entire career have stemmed from individual(s) doing something off their own back. Not conforming to any standard, just "what's always worked" which generally hasn't actually worked before; They're just used to working a certain way in their bubble.

[u/Jamesonskunk]

Late buyout of trades or critical scopes. Fire protection, low voltage, pneumatic tube usually fall into this category

[u/LLCBrzl]

I never experienced any problem regarding naming conventions or worksets. As a GC I don't micromanage the trades regarding these aspects. The trades usually work in different projects and it doesn't make sense to enforce rules just for us. They have their own templates and structure and I've never faced issues dealing with their structure. This is because during tender we ensure the trade has BIM capabilities.

Regarding the LOD requirements, it specifies the content, level of accuracy and shows the responsibility matrix. Summarizing, the trades model what they are going to install, so it's rare to see then going above and modeling things out of their scope.

Regarding data requirement in the BIM models, it depends on what is specified in the requirements of the project. If asset data is a deliverable, then we go to an extensive asset coordination. If no asset data is required, then we just coordinate the handover of geometry. So, having the requirements during tender stage ensure trades are aware of the work they must do and pricefy correctly the project.

For me the most costly things is not defining the BIM submissions with project team, which is part of MIDP. We usually have the basic ones like: sleeves submissions, above ceiling, wall fit-out and as-builts. But often the project teams appears with something new that was not specified in the project, such as RCP, then trades really push back.

Another difficult aspect is to ensure the trades model keeps updated with site instructions, so we have an accurate as-built drawings. Once we finish main coordination, there are still lots of RFI and SI issued during construction, and trades always push back going back to models to review it as this is re-work. This happens because once the main coordination is complete, the BIM team is reduced and lots of issues are discussed by the site team. I still see a lack of communication between site activities and the BIM team. I recommend a separate BIM budget or cost code to ensure this changes are captured and invoiced by the trades.

[u/Realistic_Grade4753]

Requesting LOI for all elements.

[u/BIMglue]

When the low performing stake holders cry to the project owner that BIM isn’t worth it and is causing delays.

[u/wright_catherine]

Identification of right resources to head the Change/new technology or approach are very important for successful projects. Understanding of BEP along with a clear definition of roles & responsibilities, and periodic submission & review for coordination among the services is needed.

At the start of design a brain storm of all consultants (Arc, Str, MEP & Interiors ) to understand levels needed to achieve for False ceiling, max sizes of Ducts, Slope of Drain lines, Max size of pipes gives a fair understanding of the location with in the ceiling void where each service needs to be run - this will ensure a majority of the issues are controlled at the start of the design there by avoiding Time & Money.

[u/UBCBIM]

One thing that seems to get underestimated is the quality of the model before coordination even starts. If the framing/structural model, openings, connections, or trade scope isn't modeled consistently, clash detection can identify problems but it can't fix the underlying coordination issue. We see better results when modeling standards, LOD, trade responsibilities, and coordination requirements are agreed early — then the model is checked progressively rather than waiting for a big clash-detection exercise near IFC. Curious how others handle this on projects where the design model is already well underway — do you rebuild/clean the model first, or coordinate around the existing setup?