The War Story Every Multifamily Developer Knows
Every multifamily developer has a war story. The one where the mechanical contractor opened up the ceiling and found a shear wall where the ductwork was supposed to go. Or the plumber roughed in the gas lines only to discover the equipment had been relocated three RFIs ago. MEP coordination failures aren’t rare edge cases — they’re the single largest source of change orders on multifamily projects.
The numbers are stark. Industry data shows the average RFI costs $1,080 to process. On a typical 200+ unit multifamily project, 30–50% of all change orders trace back to coordination gaps between mechanical, electrical, and plumbing disciplines. When those gaps are discovered during construction rather than design, the cost multiplier is 10x or more.
Why MEP Coordination Fails
The root cause is straightforward: each discipline designs in isolation. The mechanical engineer sizes ductwork without seeing the structural framing. The electrical engineer designs panel schedules without knowing the plumber added an electric water heater. The landscape architect specifies an irrigation controller that nobody tells the electrical engineer about.
Traditional plan review catches some of these — but it’s a human scanning hundreds of sheets across 6–7 disciplines. Cross-discipline conflicts are the ones that slip through because no single reviewer owns the space between disciplines.
Real MEP Coordination Failures from Actual Projects
The following examples come from real multifamily projects. Each generated documented RFIs and change orders.
Structural vs. Mechanical: Shear Wall Blocks Duct Routing
A clubhouse conference room had a structural shear wall extending through the south wall — directly in the path of three continuous HVAC duct sections. The conflict required approximately 6 feet of shear wall removal and structural redesign with new steel reinforcement. Discovered during construction, it generated a change order in the $28,000–$45,000 range and a 14–21 day delay. Had the structural wall footprint been overlaid against mechanical routing during design, this would have been a drawing revision — not a field rework.
Structural vs. Mechanical: Roof Trusses Obstruct Exhaust Vents
Roof trusses were positioned in direct conflict with exhaust vent routing paths. Vents couldn’t run without cutting or modifying trusses — discovered after framing was complete. Field photos documented wood blocking where vents needed to penetrate. This is one of the most expensive discovery timelines: full rework with framing already in place.
Electrical vs. Plumbing: Dog Wash Facility Power Missing
The plumbing plans showed an electric water heater for the dog wash facility. The electrical plans showed minimal power — no dedicated circuit for the heater. Cost to add after the fact: $1,800–$3,200. A simple cross-reference of equipment schedules would have flagged the missing electrical load.
Electrical vs. Landscape: Irrigation Controller Has No Power
This one appeared on two separate projects. Landscape plans specified irrigation controllers (requiring 120V service and dedicated circuits), but electrical drawings showed no corresponding power feed. Cost per controller circuit: $2,200–$5,600. It recurs because landscape and electrical work in silos — irrigation is treated as an afterthought by the electrical engineer. This is exactly the type of recurring pattern that AI plan review can flag automatically once the pattern is documented.
Mechanical vs. Plumbing: Gas Supply Removed but Equipment Remains
A markup note on one project’s plans read “Remove natural gas will be provided” — removing gas supply from scope. But the outdoor kitchen equipment (which requires gas) was still shown on the landscape plans. Nobody cascaded the scope change. This type of scope ambiguity generates RFIs, delays procurement, and creates finger-pointing between trades.
Electrical vs. Mechanical: Pool Equipment Relocated Without Electrical Update
Pool equipment was relocated per an earlier RFI, but the electrical service to the new location was never confirmed on the electrical drawings. Two additional RFIs were generated to resolve the power routing — each adding coordination time and potential schedule impact.
The Pattern: Missing Coordination Is the #1 Conflict Type
Across 161 documented conflicts from four real multifamily projects, the breakdown is revealing:
- Specification mismatches: 40% — conflicting dimensions, materials, or equipment ratings between disciplines
- Missing coordination: 35% — equipment shown on one discipline with no corresponding service on another
- Code violations: 15% — non-compliance with building codes, ADA, or fire protection
- Spatial clashes: 10% — physical interference between elements
Missing coordination alone accounts for more than a third of all conflicts. These aren’t hard clashes that BIM would catch — they’re soft coordination gaps where one discipline simply didn’t talk to another.
What Early Detection Saves
The economics are simple. A coordination conflict caught during design review costs $500–$2,000 to fix (drawing revision). The same conflict discovered during construction costs $5,000–$25,000+ (field rework, re-mobilization, schedule impact). On a project with 15–25 preventable conflicts, the math adds up fast.
AI-powered plan review doesn’t eliminate the need for MEP coordination meetings. It makes them dramatically more productive by flagging the conflicts before the first meeting happens — so the team spends time solving problems instead of finding them.