Millwork BIM Coordination Done Right: IFC Workflows for LOD 350 vs LOD 400 & Production Readiness

Your team just finished the fabrication-ready model for a hotel reception desk. Every joint, every dowel, every cam lock, every CNC toolpath was included in one detailed file.

To be thorough, you export the whole file and send it to GC as your coordination submission.

Two days later, you get a call. Their coordination software has become very slow. The clash detection tool is showing hundreds of conflicts, but most of them are not real problems like internal screws touching internal plywood.

But, somewhere in that long list, there is an actual clash between your desk and an HVAC duct. This unnoticed clash becomes a real problem on site after a couple of weeks.

See, nothing was wrong with your model. You simply shared more information than the GC needed at this stage.

This is the exact problem in millwork BIM coordination that causes the most confusion for millwork shops and GCs: not whether IFC works, but how much of your model you should share, and at what stage.

Sharing too little, GC cannot properly coordinate your millwork with the rest of the building. Sharing unnecessary fabrication detail, you create a large, cluttered coordination model filled with information the wider project team does not need.

That is the real issue behind most millwork submittals today. In Part 1, we explained what IFC is and why it matters. Here, keep reading to know what should be included in your IFC export, at what stage to ensure submittal goes well.

The LOD 350 vs LOD 400 Boundary

Level of Development, or LOD, describes how complete and reliable the information in a model is at a given stage. For millwork, two levels matter most, and understanding the difference between them is the foundation of good millwork BIM coordination.

• LOD 350 helps the GC and architect see how your millwork fits with walls, floors, MEP lines, and other parts of the building i.e. removing clashes and maintaining coordination between disciplines.

• LOD 400 includes full fabrication detail such as joinery, hardware, dowels, and CNC toolpaths, used for manufacturing on the shop floor.

There is no fixed rule that says LOD 400 information can never be shared with the GC or architect. What actually needs to be shared should follow your project’s BIM execution plan (BEP) and submittal requirements.

Some projects only need a simple LOD 350 model for coordination. Others, depending on the contract, may require more detail.

What stays the same across projects is the purpose of each level:

The simple approach is this: use a light model for coordination that everyone can work with easily and use a detailed model for fabrication that your production floor actually needs.

A Reception Desk in Motion: IFC on a Real Project

Now let’s look at the same type of hospitality millwork project as discussed in intro.

An architect designs a reception desk for a hotel lobby. It is eighteen feet long, with a stone countertop, veneer finish, built-in electrical outlets and LED lighting underneath.

Full LOD 400 fabrication model includes panel thickness, joinery, hardware, drawer runners, hinges, fasteners, and manufacturing tolerances. This detailed version stays inside your shop.

For coordination, you export a simpler LOD 350 model instead. It includes only the outer dimensions, attachment points and MEP clearances.

Simultaneously, other work is also happening on the project. The MEP engineer has routing conduits below the desk. The electrical consultant is adding sockets. The contractor is adjusting floor levels for the lobby finish.

Everyone exports their own coordination-level IFC file. GC brings all of these files into Navisworks or a similar platform.

So, if the floor level was changed after the model was finalized, it gets showed up clearly in the combined model. Everything is done during the coordination meeting i.e. long before a single plywood or material is cut.

How IFC Helps Prevent “Model Mismatch” Submittal Rejections

A typical millwork submittal usually includes shop drawings, material specifications, finish schedules, hardware schedules, and, increasingly, a BIM model.

IFC does not remove the risk of mismatch by itself. What it does is support a clearer review process. The general sequence looks like this:

1. the source model is exported correctly

2. checked for accuracy

3. added to the coordination model

4. reviewed for clashes

5. revised if needed and then approved.

This is different from reviewing flat 2D drawings. An architect looking at a drawing can only see what is shown on that one page. An architect looking at a properly prepared IFC model can see your millwork placed directly inside the building, next to everything around it.

Questions about clearances, ADA requirements, knee space and outlet placement are answered within minutes with BIM 3D Model. Unlike going emails that take weeks to resolve!

Fewer open questions lead to fewer rounds of revisions. Fewer revisions mean the submittal gets approved sooner.

How IFC Drives True Interoperability Across Project Stakeholders

Consider everyone involved in a commercial project: architect, interior designer, structural engineer, MEP consultant, general contractor, millwork fabricator, and owner. Each of them works in different software, but all of them need to see the same building the same way.

Without a shared format for exchanging data, each team ends up rebuilding parts of someone else’s model just to check their own work.

This takes REAL TIME and EFFORT!

Even though it never appears as a separate cost on an invoice. It still affects your project’s margins and bottom line.

With IFC, everyone works from the same coordinated model, even though each team still creates its own part of it separately.

No one has to guess what changed since the last update. No one has to rebuild geometry from scratch just to check the clearance. This saves real time throughout the project, not only during the submittal stage.

A Common Misconception About IFC Files for Millwork

At BluEnt, a common statement we hear is, “IFC is just another file format.”

See, that’s not true. IFC is a schema.

It’s a defined structure that describes how elements like walls, doors, materials etc. along with their properties are organized. This is done so that different BIM software can read and understand them the same way. It works less like a single file type and more like a shared set of rules that different software programs agree to follow.

IFC versions also matter. IFC2x3 is still the most commonly used version across the industry. IFC4 and IFC4.3 are being used more, especially for projects that need more detailed data. IFC5 is still being developed. Knowing which version your project requires, before you export, prevents confusion later.

Without IFC, teams spend more time converting and fixing files than solving actual construction problems. This is the main reason IFC exists.

How IFC Works Alongside Millwork Shop Drawings

A reasonable question at this point is, if we already produce millwork shop drawings, why do we also need IFC?

IFC and shop drawings are not competing with each other. Each one serves a different purpose on the same project.

Your shop drawings remain necessary on the production floor. Your IFC model is useful during coordination, because it lets the GC and architect see your millwork placed correctly within the building, instead of on a flat page.

Neither one replaces the other. Together, they cover the full process from design to a finished, installed piece.

BluEnt’s Checklist for Delivering Coordination-Ready IFC Files

Most IFC problems start with something simple such as missed information, wrong LOD, wrong version, or unclear naming. BluEnt’s millwork engineering team performs QC checks to help catch that early, before it becomes a bigger issue later.

Every IFC export at BluEnt goes through the same checks before it is sent out.

• Confirm object classification, so BIM software correctly identifies the millwork

• Preserve model hierarchy and element properties, so nothing turns into a flat, uneditable shape

• Check coordinates and project base points, so the model is placed correctly on site

• Review object naming for consistency across the model

• Avoid default export settings. Adjust them to match the project’s LOD requirement, IFC version, and classification codes

• Run clash detection before submission, not after

• Check exported files in a neutral BIM viewer, to confirm the geometry is correct before sending it to the client

• Coordinate any revisions with architects and contractors before fabrication begins

How BluEnt Supports Millwork BIM Coordination

Adjusting to openBIM workflows can feel difficult when your in-house detailing team already has a full workload. This is where BluEnt, the USA’s leading millwork drafting company, can help.

With over two decades of experience in architectural detailing, millwork engineering, and BIM coordination, we work alongside your team rather than replacing it. We help millwork shops, fabricators, and GCs turn detailed production data into clean, coordination-ready IFC models. In practice, this means:

• Faster submittal approvals ( fewer revision rounds, RFIs)

• Fewer surprises on the job site because clashes are identified early

• More capacity for your in-house team without hiring additional staff

If you want millwork BIM coordination to be more predictable, reach out to BluEnt’s millwork detailing experts today.

Final Thoughts

An IFC file does not manufacture a cabinet and neither does it replace shop drawings.

But what it does is give everyone, the architect, the GC and millwork shop, a reliable way to stay coordinated across different BIM software, at different stages of the same project.

This is the main goal of good millwork BIM coordination. It is not about one perfect file, it’s about knowing what information to share, at what stage, and why.

Get the LOD 350 vs LOD 400 decision right and the rest of the coordination process becomes much easier to manage.

FAQs

What’s the actual difference between LOD 350 and LOD 400 in millwork?LOD 350 is typically used for coordination between disciplines and includes outer dimensions and connection points. LOD 400 is typically used for fabrication and includes full joinery, hardware, and manufacturing detail. The level you share with the GC depends on your project’s BIM execution plan.

What is millwork BIM coordination?Millwork BIM coordination is the process of combining 3D millwork models with architectural, structural, and MEP models to identify and resolve clashes before fabrication or installation. IFC files help teams exchange this model information between different BIM software platforms for better coordination.

Does IFC replace the need for shop drawings?No, an IFC file shows the overall architectural design intent, spatial layout, and 3D coordination. Millwork shop drawings show how the custom woodwork will actually be built and installed. Both are needed together.

Will exporting an IFC model expose our proprietary fabrication methods?Not necessarily. Actually, what gets shared depends on what you choose to model and export. A properly scoped millwork BIM coordination export shares spatial and material information without including your internal joinery and production methods.

Does using IFC guarantee that our submittal will be approved faster?IFC supports a clearer coordination process, which reduces the risk of mismatch, but it is not a guarantee by itself. Approval speed still depends on model accuracy, proper checks and how quickly clashes are resolved.

Who decides what LOD level should be shared with the GC?The project owner, the lead architect/design team, and the General Contractor (GC) collectively decide what Level of Development (LOD) should be shared, rather than a single individual making the decision. This is usually defined in the project’s BIM execution plan and submittal requirements.