IFC Model Comparison
for Structural Member Geometry

StructMatch is an IFC model comparison tool focused on structural member geometry.

You can load two IFC files, and the system will try to find corresponding columns, beams, and braces, then check whether their section, length, horizontal position, elevation, angle, or shape is different.

It is not intended to list every changed property or parameter in the model. The goal is to narrow the result down to one question: did the structural member geometry change?

A complete BIM model can contain a large number of properties, names, tags, classifications, and nonstructural objects. General version comparison can easily generate many changes that are technically real but not relevant to the check you are trying to perform.

StructMatch deliberately narrows the scope to structural members such as beams, columns, and braces, then separates the differences into section, length, horizontal position, elevation, angle, and shape.

This makes it easier during coordination or pre-issue review to answer a simple question: are the structural members in these two models geometrically consistent?

If you have two IFC files and what you actually care about is whether beams, columns, and braces are geometrically consistent, StructMatch is a good fit.

• Compare different versions of the same structural model and find modified, added, or removed members
• Compare beam and column sizes and positions between Revit and ETABS / SAP2000 models
• Check major structural members during architecture–structure coordination
• Verify primary member geometry between design and fabrication / detailing models
• Quickly check whether length, section, or position shifted after model conversion or exchange

The system mainly reads two core pieces of information for each member: section and axis.

The section represents member size, such as RECT-500x800, BOX-300x300x12, or H-400x200x8x13.

The axis can be understood as the centerline along the member length. After extracting it, the system uses the axis to describe position, angle, shape, and length, together with other geometry information to find likely corresponding members. Once pairing is complete, section and geometry differences are checked item by item.

The system reads the member section and uses the axis as the basis for position, angle, shape, and length checks.

During pairing, the system uses each member in Model A as a reference and searches nearby for possible corresponding members in Model B.

If the two model coordinate systems are not aligned, corresponding beams or columns may be too far apart, causing the system to miss the correct pairing.

Therefore, when the two model origins or coordinates differ significantly, it is recommended to align the models first. The system can then search for corresponding members within a reasonable range and proceed with comparison.

“Pairing” determines which member or members in Model B correspond to a member in Model A. Common pairing situations include:

• One member in Model A corresponds to one member in Model B
• One member in Model A corresponds to multiple members in Model B due to different modeling methods
• Multiple members in Model A correspond to one member in Model B due to different modeling methods
• A member exists only in Model A when no corresponding member is found
• A member exists only in Model B when no corresponding member is found

“Comparison” checks whether paired members have differences, such as position, angle, section, shape, or length differences.

Simply put, pairing finds “which members belong together,” while comparison checks “whether there are differences within the pair.”

After pairing, the system marks position, length, section, and other differences within the same member group.

Ideally, the system can directly read each member’s section size from the IFC data.

In real projects, some members may be affected by joins, cuts, end trimming, conversion, or software-specific IFC export methods, making it difficult to infer the original section from geometry alone.

For example, a rectangular beam may be cut by columns, walls, or other elements at its ends, so its geometric shape is no longer a clean rectangle. In this case, geometry alone may not be enough to identify the correct section.

Section naming rules are used when geometry-based section detection is insufficient. The member name can then be used to specify the section size.

For example:

• Map member name G50x80 to RECT-500x800
• Map member name BOX150 to BOX-150x150x12
• Map member name G402 to H-400x200x8x13

Automatic section naming detection: the system first attempts to find patterns in existing member names and apply possible section naming rules. Users can confirm, edit, or add rules to match project or company naming conventions.

Module rule: parse the section from size modules in the name
For example: G{B}x{H}.

Section name rule: map a specific name directly to a standard section
For example: H-148x100x6x9.

If the automatic result is not as expected, you can correct it based on the type of issue.

• If section parsing is incorrect, add or adjust section naming rules, or directly map a type of name to a section.
• If pairing is incorrect, use manual pairing, unpairing, or rerun local pairing.
• If some members should not be compared, add them to the ignore list.
• If the comparison is too strict or too loose, adjust comparison tolerances such as position, angle, length, or shape thresholds.

These features help the tool adapt to different company modeling habits, IFC export results from different software, and project-specific checking requirements.

Yes.

Users can adjust comparison items and certain tolerances based on project needs. For example, you can choose whether to compare position, angle, shape, section, or length, and adjust thresholds for position offset, angle difference, and length difference.

This is useful at different stages of model checking. During early coordination, you may only care about the section and position of major beams and columns. Before drawing issue or model delivery, you may use stricter tolerances for horizontal position, elevation, angle, and length.

The system temporarily processes uploaded IFC files and comparison results in order to complete the model comparison workflow.

The system regularly clears uploaded data and generated results. Temporary data is generally removed within 24 hours.

If you choose to provide IFC files through the feedback form and describe the issue you encountered, it will greatly help improve section parsing, pairing accuracy, and compatibility with IFC exports from different software.