BIM Execution Plan (BEP) and Level of Development

A BIM Execution Plan (BEP) is the project-specific document that defines how a team will use building information modeling: who authors which model elements, what Level of Development each discipline reaches at each phase, how models federate together for coordination, and who owns clash resolution. It gets negotiated at kickoff, usually led by the architect or a BIM manager, and it's the reference every discipline points back to when a coordination dispute comes up mid-project.

Teams that skip a real BEP, or write one nobody actually agreed to, tend to find out the hard way: at a coordination meeting, when the MEP model is at LOD 200 and the structural model is at LOD 350, and neither side realized the mismatch until clashes that should have been caught months earlier show up during cross-discipline coordination.

What does a BIM execution plan actually define?

A BIM execution plan defines who models what, the LOD required at each phase, how models federate, and who owns clash resolution.

• Model authorship: which discipline models which building systems, and where responsibility overlaps (structural steel connections modeled by the fabricator, not the SEOR, for example).
• LOD by phase: the Level of Development every model element has to reach at schematic design, design development, construction documents, and fabrication.
• Federation strategy: how individual discipline models combine into a coordinated model, including software, file formats, and coordinate systems.
• Coordination responsibility: who runs clash detection, how often, and who owns resolving a conflict once it's found.
• Deliverables: what gets extracted from the model at each phase, including the 2D drawing sets required for permitting and field use.

How does Level of Development change phase by phase?

LOD describes how much a model element can be relied on, not how visually detailed it looks. A structural column modeled as a simple box at LOD 200 and a fully detailed column with connection plates at LOD 400 might look similar on screen, but only one of them is ready to fabricate from.

Mapping these levels against the drawing set phases a project issues (SD, DD, CD, IFC) keeps the model and the extracted drawings honest about how much detail each one is supposed to carry at a given point.

Why does drawing review still matter after the BIM model is complete?

Most jurisdictions still require a 2D PDF set for permitting, and most field crews still work from printed or PDF sheets rather than pulling up a live federated model on a tablet mid-pour. That means the drawing set gets extracted from the model at a point in time, and it can quietly drift out of sync as the model keeps evolving after that extraction, unless the team has a disciplined re-extraction process locked into the BEP itself. This is the mechanism behind the BIM-to-field gap: not that the model was wrong, but that the sheet in the field was extracted before the model's last revision.

That's also where a review approach that reads the drawing set directly earns its keep on a BIM-driven project, not as a replacement for model coordination, but as a check on whatever actually got issued for construction. Helonic reads the 2D sheets a project issues, whether they came from a fully federated BIM workflow or a traditional drawing-based process, and flags coordination conflicts on the documents crews actually build from, independent of whether the source model itself was current when the sheet was pulled.

What belongs on a practical BEP checklist?

A practical BEP checklist covers authorship, LOD, coordinates, clash cadence, and the 2D drawing deliverables extracted from the model.

• Get every discipline's sign-off on the BEP before design starts, not just the architect's.
• Set LOD targets per phase and per discipline, and revisit them if a discipline falls behind, rather than letting a mismatch surface at coordination review.
• Assign a re-extraction trigger for 2D drawing sets: what model change threshold requires pulling new sheets before the field gets stale ones.
• Name who owns clash resolution for each discipline pairing (structural-MEP, architectural-structural), not just who runs the clash detection software.
• Review the extracted drawing set itself, not just the model, since the drawing set is what most reviewers, inspectors, and field crews actually work from, following the same discipline described in how to review construction drawings.
• Run a completeness check on every extracted set before it goes out, confirming the sheet index and drawing set completeness match what the model actually contains at that revision.