How BIM Saved a Skyscraper Project: A Clash Detection Case Study

 From the Project Files of a BIM Manager on a 72-Story Challenge

When I first walked into the coordination meeting for SkyRise 72—a 72-story mixed-use skyscraper in the heart of a seismic zone—I had no idea that Building Information Modeling (BIM) would soon become our project's lifeline. What began as an ambitious tower almost became a coordination nightmare—until clash detection turned chaos into clarity.

The Project: Vertical Complexity in Action

• Location: Urban metro zone in a high-seismic-risk region
• Height: 312 meters / 72 floors
• Use: Commercial + Residential + Podium Parking + Helipad
• Tools Used: Revit, Navisworks Manage, BIM 360, Dynamo, and later, Tekla Structures for steel coordination

Our BIM Execution Plan (BEP) defined Level of Development (LOD) 300 for design coordination, escalating to LOD 400 for structural and MEP elements during shop drawing development. Weekly model updates were mandated through a CDE (Common Data Environment), synced to BIM 360 Docs.

The Problem: Hidden Clashes Below the Surface

By the time we reached 30% construction documentation, our federated model was teeming with hundreds of micro-clashes—many of them between:

• HVAC ductwork and transfer beams
• Sprinkler risers intersecting shear walls
• Cable trays clashing with raised floor systems
• Most dangerously: a vertical shaft that unknowingly intersected a post-tensioning zone of the core slab.

Had this gone unnoticed, the cost of rework during post-tensioning installation would’ve exceeded $450,000, not to mention delay penalties.

Enter Clash Detection: The Game Changer

I scheduled a detailed clash detection session in Navisworks Manage, using the following matrix:

Discipline A	Discipline B	Priority	Tolerance
Structure	MEP	High	5 mm
Architecture	HVAC	Medium	10 mm
MEP	Firefighting	High	5 mm

We ran over 42 clash tests with set rules using “search sets” and “selection trees.” Then came the moment of truth—1,160 clashes detected, with 172 marked “Critical.”

One standout clash: an electrical bus duct running through a diagonal bracing beam on Level 39. A structural compromise and electrical risk!

The Fix: Coordinated Collaboration through BIM

After clash reports were issued, we entered coordination mode using the BIM 360 Issues tool. Each clash was tagged, assigned, and monitored through real-time markups. Key solutions included:

• Offsetting HVAC ducts via Dynamo scripts to automatically reroute around beams
• Reconfiguring electrical risers using vertical stacking strategies
• Reshaping the core shear wall geometry for better shaft alignment (approved after a structural peer review)

Weekly coordination meetings were never the same again. The live clash matrix gave our architects and consultants a single source of truth. And instead of endless RFIs and change orders, we resolved 93% of clashes virtually—before a single duct was hung on-site.

Field Feedback: BIM in the Real World

Our construction lead said something that stuck with me:

“Usually we mark and move on-site. This is the first time our sleeves and core drillings are going exactly where the model says. No rework, no second guessing.”

BIM didn’t just save money—it gave the site team confidence. Pre-coordinated hanger layouts and point cloud scans aligned with the model within ±15 mm tolerance. That precision prevented rebar hits, penetrations in post-tensioned slabs, and change orders from subcontractors.

The ROI: Measurable and Mind-Blowing

Key Outcomes:

• Cost Avoidance: Estimated $780,000 saved in avoided rework
• Schedule Saved: 21 days recovered in vertical MEP riser installation
• Risk Reduced: 100% of post-tension slab penetrations pre-approved
• Digital Twin Foundation: Clash-free as-built model now serves FM (Facility Management)

Final Thoughts: Clash Detection Isn’t Just a Feature—It’s a Strategy

This project taught me that clash detection isn’t about avoiding conflict. It’s about facilitating communication between disciplines, aligning intent, and reducing ambiguity.

Without BIM and its clash detection capabilities, SkyRise 72 could have been a cautionary tale. Instead, it became a benchmark for integrated project delivery.

Want to Level Up Your BIM Coordination?

At Roots BIM LLC, we bring lessons like these to every high-rise, hospital, or hyperscale data center we touch.
Because smart modeling does not just build—it prevents failure before it starts.

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From clash detection to full-scale digital twins, we ensure your models don’t just look good—they build smarter.

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