■ MEP BIM INSIGHTS — BIM GUIDES

What Is a BIM Execution Plan — And Why It Matters Before Day One

Most BIM coordination problems are not technical problems. They are planning problems. The wrong LOD specified. File formats agreed on verbally but never written down. Clash detection responsibility assigned to no one in particular. The model delivered in a format the structural engineer can’t open.

A BIM Execution Plan (BEP) exists to prevent exactly this. It is the document that defines how BIM will be used on a project — before a single element is modeled.

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What a BEP Actually Is

A BIM Execution Plan is a project-specific document that establishes the rules of engagement for all BIM contributors on a project. It is typically prepared by the lead designer or BIM manager at project kickoff and agreed upon by all parties before modeling begins.

In the US, the BEP is referenced in AIA Document E203 (BIM and Digital Data Protocol) and the AIA G202 (Project Building Information Modeling Protocol Form). On public projects, owner agencies — including GSA, the US Army Corps of Engineers, and many state DOTs — mandate BEPs as part of their BIM requirements.

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What a BEP Contains

01. Project Information

Basic project data: name, address, owner, design team, contractor, and the schedule of BIM deliverables tied to project milestones. This section also identifies the BIM Manager — the person responsible for model coordination — and their counterpart on the contractor side.

02. LOD Matrix

The Level of Development matrix defines what LOD each model element will be developed to, by whom, and at which project phase. A typical commercial project BEP specifies LOD 100–200 at schematic design, LOD 300 at construction documents, and LOD 400 for prefabricated elements during construction.

Without a LOD matrix, every contributor models to their own interpretation of “enough detail.” The federated model becomes unreliable for coordination.

03. Software and File Formats

Which software each discipline uses. Which Revit version. How files are named (file naming convention). What formats are accepted for model exchange (RVT, IFC, NWD). What the coordinate system and project base point are — critical for federated model alignment.

A mismatched Revit version or an off-origin model can cost days of rework. This section prevents both.

04. Collaboration Workflow

How models are shared and updated. The Common Data Environment (CDE) — BIM 360, ACC, ProjectWise, or a shared server. Model issue frequency (weekly? bi-weekly?). How RFIs and design changes are communicated to the BIM team. Who has write access to which models.

05. QA/QC Process

Who runs clash detection. Which clash types are hard clashes (must be resolved) vs. soft clashes (reviewed case by case). Who reviews the clash report. What the resolution timeline is. Who signs off before the model is issued to the next phase.

06. Deliverables and Milestones

What gets delivered, in what format, and when. Coordinated Revit model at 50% CD. Clash-free federated NWD at 100% CD. As-built model at project closeout. IFC export for owner facility management system. COBie data if required by the owner.

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Pre-BEP vs. Post-BEP: What Changes

On projects without a BEP, the first coordination meeting is spent establishing what everyone should have agreed on at kickoff. Which Revit version is the structural engineer using? Who is responsible for updating the ceiling plenum zone model after the mechanical engineer reroutes? Is the contractor’s fabrication model in scope or not?

On projects with a well-prepared BEP, the first coordination meeting covers actual coordination. The ground rules are already set. Time is spent on design decisions, not process decisions.

The difference compounds over a project. Every hour spent re-establishing process in a coordination meeting is an hour not spent resolving clashes.

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When Is the BEP Prepared?

The BEP should be drafted before the first model file is opened — ideally at the same time as the project execution plan or design kickoff. In practice, this means:

• Design-build projects: At GC/design team kickoff, before schematic design begins
• Design-bid-build projects: A preliminary BEP is prepared by the design team; the contractor updates it at construction kickoff
• Renovation projects: Before point cloud scanning, so the as-built modeling scope is defined in advance

A BEP written after modeling has started is not a BEP. It is documentation of decisions that have already been made inconsistently.

What We Require Before Starting Any Project

At GEOMETRY-S, we require a project BEP — or prepare one with the client — before beginning any MEP modeling or engineering scope. Our kickoff call covers the six BEP sections above, and we provide a written scope confirmation that functions as a project-specific BEP for engagements where no formal document exists.

This is not bureaucracy. It is the single most reliable way to ensure that what we deliver is what the project actually needs — on the first submission, not the third revision.