Coordination

Top 5 MEP vs. Structural Clashes

The most expensive coordination failures happen where MEP systems meet structure. These clashes cause delays, change orders, and field rework. Learn where they happen and how to prevent them.

Understanding Clash Types

Hard Clash

Physical overlap between two elements—a duct intersecting a beam, pipe through a column. These must be resolved; the building cannot be constructed as drawn.

Soft Clash (Clearance)

Elements don't physically touch but violate required clearances—not enough space for insulation, maintenance access, or code-required separations.

Workflow/4D Clash

Installation sequence conflicts—one trade cannot install their work because another trade's incomplete work is in the way. Common with ceiling systems.

The Most Common Clashes

Ductwork vs. Structural Beams

HVAC + StructuralHigh Impact

Main supply and return ducts often run perpendicular to structural framing, creating conflicts at beam intersections. This is the most common and costly clash on commercial projects.

Common Causes

Ceiling plenum height assumed without verifying beam depths

Duct sizes increased during design development without re-routing

Structural engineer adds moment connections that deepen beams

Mechanical contractor selects different equipment with larger duct connections

Prevention Strategies

Establish ceiling plenum zone early with beam bottom elevations

Route major ducts parallel to beams in corridors

Request structural beam schedule before mechanical design

Add 6" vertical buffer in BIM clash detection tolerance

Plumbing Risers vs. Structural Columns

Plumbing + StructuralHigh Impact

Vertical plumbing stacks and structural columns compete for the same core locations. Moving either element post-construction is extremely expensive.

Common Causes

Restroom stacks not coordinated with column grid

Columns shifted during structural optimization

Multiple chase locations shown on different drawing sets

Plumbing designer using outdated architectural backgrounds

Prevention Strategies

Lock vertical chase locations in schematic design phase

Require plumbing designer to overlay structural column grid

Create dedicated coordination drawings for core areas

Include chase locations in early interdisciplinary reviews

Conduit/Cable Tray vs. Beams & Joists

Electrical + StructuralMedium Impact

Electrical conduit runs and cable trays frequently conflict with secondary structural framing, particularly bar joists and composite deck framing.

Common Causes

Electrical designer routes conduit at constant elevation

Bar joist depth not accounted for in routing

Large conduit runs added for data/low voltage late in design

Equipment locations move, requiring re-routing through structure

Prevention Strategies

Route large conduit runs in dedicated corridors

Verify joist bottom elevations before conduit routing

Reserve chase locations through bar joist bays

Consider cable tray for flexibility in routing

Fire Sprinkler Mains vs. Structure

Fire Protection + StructuralHigh Impact

Fire protection mains and branch lines must maintain proper pitch for drainage while navigating around beams. Conflicts often discovered during installation.

Common Causes

Sprinkler design completed after structural steel fabrication

Branch line pitch requirements forgotten in tight plenums

Main drain locations conflict with footings or grade beams

Sprinkler heads centered in ceiling tiles hit beams above

Prevention Strategies

Include fire protection in early design coordination

Route mains parallel to structural bays

Verify head locations against beam layout

Coordinate drain-down and test connections with site civil

Mechanical Equipment on Structure

Mechanical + StructuralMedium Impact

Rooftop units, air handlers, and pumps require structural support that is often undersized or mislocated, especially when equipment is selected late.

Common Causes

Equipment weights estimated low in early design

Vibration isolation requirements not communicated

Equipment pads shown schematically, not coordinated with structure

Dunnage and curbs added without structural review

Prevention Strategies

Require mechanical equipment schedule with weights early

Coordinate housekeeping pad locations with slab reinforcing

Include vibration isolation in structural loading

Review equipment anchorage and seismic requirements

Clash Detection Best Practices

Run Checks Early & Often

Don't wait for 100% CD. Run clash detection at 50% DD, 100% DD, 50% CD, and 100% CD. Early clashes are cheap to fix.

Set Realistic Tolerances

Hard clashes need 0" tolerance. Soft clashes for maintenance access might need 18-24". Insulation clearances need 2-4".

Assign Clash Ownership

Every clash needs one responsible party. Unassigned clashes don't get resolved. Track resolution status weekly.

Focus on High-Value Areas

Mechanical rooms, vertical shafts, and ceiling plenums cause 80% of coordination issues. Prioritize these zones.

Catch Clashes Before They Cost You

Don't have time to manually overlay every structural and MEP sheet? Articulate's AI can scan your PDFs and identify potential coordination conflicts in seconds—without expensive BIM software or 3D modeling.

Find clashes on 2D drawings before they become 3D problems in the field.

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Based on industry coordination best practices and common construction project data. Every project is unique—always conduct project-specific coordination reviews.