F&K Estimatings
Field Case Study #04

The $85,000 VFD Disconnect

Catching the margin bleed between Division 23 (Mechanical) and Division 26 (Electrical) during the GMP validation phase.

1. The Problem

We were hired by a regional General Contractor to perform a third-party estimate review on a $14M high school renovation prior to finalizing their Guaranteed Maximum Price (GMP) contract with the school district. The GC had already received bids from their preferred mechanical and electrical subcontractors.

2. The Scope Gap

During our Constructability Review, our MEP estimators overlaid the Mechanical Equipment Schedule (M-601) with the Electrical One-Line Diagram (E-401).

The mechanical schedule listed 14 large Air Handling Units (AHUs) requiring Variable Frequency Drives (VFDs). The mechanical specs stated: "VFDs provided by Div 23, installed by Div 26." However, the electrical drawings showed standard motor starters, not VFDs, and the electrical specs explicitly excluded "mounting of mechanical VFDs and associated control wiring."

3. The Pre-Bid RFI

MEP Coordination Blueprint Markup
RFI CATCH: Unclaimed VFD Mounting & Terminations
Bluebeam Coordination

Plan Review: MEP Coordination

Generic takeoff services just click lines. Our estimating team reviews the architectural details against the structural and MEP notes. When we find a conflict, we highlight it on the plans and generate an RFI before you bid.

Our Resolution Strategy:

We issued an immediate RFI: 'Please confirm which trade is responsible for mounting the 14 VFDs, providing the fused disconnects ahead of the drives, and pulling the 0-10v control wire from the BAS panel to the drives. Neither Div 23 nor Div 26 has claimed this scope.' The engineer responded: 'Div 26 to mount and terminate. Div 23 to provide low-voltage control wire.'

4. The Bid Leveling Catch

We reviewed the actual bids submitted to the GC. The lowest electrical bidder (Sub A) had rigidly followed the electrical drawings and explicitly excluded "mechanical equipment mounting and DDC wiring."

If the GC had simply awarded the contract to Sub A based on the raw low number, the GC would have been hit with an $85,000 change order on day one to mount the drives, upsize the disconnects, and pull the low-voltage wire.

Electrical (Div 26) - Bid Leveling Matrix

GC Preconstruction Tool
Scope Line Item Subcontractor A Subcontractor B Subcontractor C
Raw Base Bid $1,450,000 $1,520,000 $1,550,000
GC Plug: VFD Mounting, Disconnects & Control Wire (RFI #12) + $85,000 INCLUDED INCLUDED
True Leveled Bid $1,535,000 $1,520,000 $1,550,000
If you only looked at the raw base bid, you would have awarded the contract to the wrong subcontractor.

5. Margin Protected (The Result)

By using the "Plug" methodology in our bid leveling matrix, we proved that Subcontractor B was actually the lowest responsible bidder, as they had proactively included the VFD mounting labor. The GC awarded the contract to Sub B, preventing an $85,000 hit to their contingency and completely eliminating the inter-trade dispute before construction began.

Case Study Summary

  • Project Type K-12 Education ($14M)
  • Failure Point Div 23 / Div 26 Interface
  • Margin Protected $85,000.00
Request a Bid Review
Bid-Risk Management

Don't Sign the GMP Yet.

Let our estimators run a constructability review and level your subcontractor bids before you lock in your fee.

Upload Project Plans for Review

NDA Protected & Confidential

Chat with us