LIBRARY // ACCURATE MODELLING AND RESEARCH

Federated Model Alignment Checks

Federated models only work if every discipline sits in the right place. Alignment checks confirm that they do.

A federated model combines models from different disciplines, such as Architectural, structural and MEP. Before coordination can start, the models must align. Misaligned models produce meaningless clash results and can hide real problems.

Why alignment fails

• Models using different coordinate systems
• Wrong shared coordinates acquired
• Different level datums
• Different units
• Models moved accidentally
• Export settings that don't carry coordinates

Agree setup first

At the start of the project, agree:

• Coordinate system and survey point
• Level datums and names
• Grid names and positions
• Units
• Exchange formats and settings

Record these in the BIM execution plan.

Check grids and levels

Grids and levels are the simplest alignment checks. In a federated model, grids from each discipline should overlay exactly, and levels should match.

Check key elements

Compare key elements, such as columns, cores and slab edges, between Architectural and structural models. They should align within agreed tolerances.

Check exports

When exporting to IFC or NWC, check that coordinate settings are correct. Export options can choose between internal, project and shared coordinates. Test exports before coordination starts.

Use a check model

Some teams create a simple model with grids, levels and a few reference objects. Each discipline links it to confirm alignment.

Check after updates

Models can move accidentally. Check alignment whenever new versions are received.

Units

Models in different units, such as metric and imperial, can cause scaling issues in some exports. Confirm units before federating.

Rotations

Report problems clearly

When models don't align, report the offset and which elements are affected, with screenshots. This helps the model author fix the setup quickly.

Record alignment checks

Record each check with the model versions and results, so alignment history is clear.

Simple alignment tests

Open the federated model and check a few known points, such as a grid intersection, a level and a corner of the building. If these line up across all models, alignment is probably correct. If they don't, stop and fix it before running clash detection.

1. 01Why alignment fails
2. 02Agree setup first
3. 03Check grids and levels
4. 04Check key elements
5. 05Check exports
6. 06Use a check model

Units and rotation

Many alignment problems come from mismatched units or a rotated true north. Check both when a model arrives looking far away or turned at an angle.

Confirming alignment before coordination makes clash detection meaningful and saves time for the whole team.

If your team needs extra production capacity for work like this, take a look at our Architectural production services, or tell us about your project.