The cost of BIM, according to ChatGPT

Estimating the budget for a BIM Management assignment during the design phase of a public building project depends on several parameters:

Here is a detailed estimate by phase:

• The complexity of the project (floor area, typology, specific requirements)
• The number of parties to coordinate
• The level of BIM requirements (LOD, LOI, BIM charters, client requirements)
• The tools and collaborative platforms used

1. SKETCH phase (ESQ) – 5 to 10% of the total budget

📌 Estimate: €4,000 to €8,000

• Defining the BIM objectives
• Drafting the BIM specifications
• Coordinating with the client on BIM strategy
• Initial exchanges with project stakeholders

2. PRELIMINARY DESIGN phase (APS) – 15 to 20% of the total budget

📌 Estimate: €8,000 to €15,000

• Drafting the BIM execution plan
• Defining Levels of Development (LOD) by discipline
• Setting up collaborative platforms
• Starting the structuring of digital models

3. DETAILED DESIGN phase (APD) – 20 to 25% of the total budget

📌 Estimate: €10,000 to €20,000

• Refining models and quality control
• Defining collaboration and verification processes
• Running the first clash detections
• Monitoring updates to the BIM execution plan

4. PROJECT phase (PRO) – 25 to 30% of the total budget

📌 Estimate: €12,000 to €25,000

• Checking BIM deliverables (LOD, compliance, data structuring)
• Verifying models for technical design studies
• Coordinating exchanges between consultants, architects and project management
• Preparing the digital as-built file (if required during design)

5. TENDER phase (DCE) – 10 to 15% of the total budget

📌 Estimate: €5,000 to €12,000

• Checking models before sending them to contractors
• Assisting in producing BIM deliverables for the tender
• Supporting contractors to ensure they understand the BIM requirements

Total estimated budget (Design phase):

💰 €39,000 to €80,000 depending on project complexity and BIM requirements.

👉 This budget may vary depending on project duration, the number of parties involved and the client's specific requirements.

Would you like a more refined estimate for a particular case? 😊

I then asked it to recalculate these estimates after analysing the BIM specifications of the Auvergne-Rhône-Alpes region against their BIM requirements

After analysing the Auvergne-Rhône-Alpes region's Digital Model Charter

, it appears that the region's BIM requirements are particularly demanding, notably regarding:

Given these heightened requirements, the budget initially estimated for the BIM Management assignment during the design phase needs to be reassessed. Here is an adjusted estimate by phase:

• Data structuring: implementing rigorous processes to guarantee rich, well-structured information on the asset.
• Roles and responsibilities: precise definition of the BIM Manager's and BIM Project Management Assistant's duties, with high expectations for coordination, supervision and verification.
• Expected deliverables: production of detailed digital models for asset management, operation and maintenance (BIM FM).

1. SKETCH phase (ESQ) – 10 to 15% of the total budget

Estimate: €8,000 to €12,000

• Tasks: Defining BIM objectives in line with the regional charter.
• Drafting the project-specific BIM specifications.
• Coordinating with the client on BIM strategy.
• Initial exchanges with stakeholders to align expectations.

2. PRELIMINARY DESIGN phase (APS) – 20 to 25% of the total budget

Estimate: €16,000 to €20,000

• Tasks: Detailed drafting of the BIM execution plan in line with regional standards.
• Precise definition of Levels of Development (LOD) by discipline.
• Setting up suitable collaborative platforms.
• Initial structuring of digital models according to regional requirements.

3. DETAILED DESIGN phase (APD) – 25 to 30% of the total budget

Estimate: €20,000 to €24,000

• Tasks: Refining models with rigorous quality control.
• Defining strengthened collaboration and verification processes.
• Running in-depth clash detections.
• Strict monitoring of updates to the BIM execution plan.

4. PROJECT phase (PRO) – 30 to 35% of the total budget

Estimate: €24,000 to €28,000

• Tasks: Exhaustive checking of BIM deliverables (LOD, compliance, data structuring).
• In-depth verification of models for technical design studies.
• Close coordination of exchanges between consultants, architects and project management.
• Preparing the digital as-built file in line with regional expectations.

5. TENDER phase (DCE) – 10 to 15% of the total budget

Estimate: €8,000 to €12,000

• Tasks: Thorough checking of models before distribution to contractors.
• Assisting in producing BIM deliverables for the tender.
• Supporting contractors to ensure they fully understand the BIM requirements.

Total estimated budget (Design phase):

Conclusion: the specific BIM requirements of the Auvergne-Rhône-Alpes region, as set out in its digital model charter, justify an increase on the originally estimated budget. This reassessment helps ensure optimal compliance with regional expectations and guarantees the quality of BIM deliverables throughout the design phases.

• Total: €76,000 to €96,000

And finally I asked... How many working days does this budget represent for each phase?

To estimate the number of working days per phase, we need to consider an average daily rate for a BIM Manager.

The daily rate can vary depending on experience and project complexity, but in the context of a public project complying with Auvergne-Rhône-Alpes requirements, we can estimate:

• BIM Manager: €700 to €1,000 / day
• BIM Coordinator: €500 to €700 / day (if technical support is needed)
• Estimated average: €800 / day

Analysis of time spent per phase

🔹 ESQ and APS phases: a lot of coordination with the client, defining BIM objectives and initial project structuring.🔹 APD and PRO phases: the most time-consuming phase, with quality control, clash detection and model verification.🔹 DCE phase: final checks and support for contractors to understand the BIM requirements.

💡 Conclusion: a BIM Manager will typically work 3 to 4 days a week over a 6-to-12-month period to cover the entire design phase. The actual need can vary depending on the real workload and the project's specific requirements.