Subcontractor Bidding and Bid Leveling

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Sub quotes typically represent 60–80% of total GMP cost on a manufacturing plant project. If you use a sub bid that’s missing scope, you’re carrying a loss. If you use a bid that’s overpriced, you don’t win the job. Bid leveling makes all bids comparable.

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Step 1: Write the Scope of Work Package

Before sending anything to subs, write a clear scope of work for each trade. A weak scope package produces incomplete sub bids that can’t be leveled.

What belongs in a scope package:

• Written scope of work narrative (what is included; what is excluded)
• Drawing list with revision numbers (exactly which drawings to price)
• Applicable specification sections
• Specific inclusions required in the bid:
  • Material type and grade
  • Labor basis (prevailing wage? union? open shop?)
  • Startup and commissioning support hours (specific number, not open-ended)
  • As-built drawing preparation
  • Warranty terms
• Statement of what the GC will provide (scaffolding, cranes, temporary power)
• Bid date and format instructions

Scope Package by Trade — Manufacturing Plant Expansion

Trade / Division	Items to Specify
Site work / Civil (31–33)	Earthwork volume (your estimate), existing utility locations, compaction spec, paving spec
Concrete (03)	Slab thickness, rebar spec, flatness F-number spec for industrial floors, vapor barrier
Structural Steel (05)	Erection only vs. supply & erect; bolt torque requirements; painting spec
Roofing (07)	Membrane type, insulation R-value, warranty year requirement
Mechanical / Plumbing (22–23)	Process utilities scope boundary (where does process pipe end and HVAC begin?), equipment connections, test & balance
Fire Suppression (21)	System type (wet/dry pipe), hydraulic calc submittal required
Electrical (26)	Voltage/phase, equipment connections, MCC supply vs. install, testing
Process Equipment Install (40–45)	Vendor-furnished scope, rigging & setting plan, startup support hours

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Step 2: Solicit Bids

• Send invitations via BuildingConnected, SmartBid, or email blast
• Allow minimum 10 working days for mechanical/electrical; 5 days for concrete/steel
• Send a reminder 2 days before due date
• Seek minimum 3 quotes per major scope; settle for 2 if market is tight

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Step 3: Receive and Review Bids

1. Log each bid in your bid tab immediately
2. Read the bid letter / cover page carefully before looking at the number
3. Note all exclusions, qualifications, and clarifications
4. Flag any bids that use different materials or methods (substitutions)

Warning signs in a sub bid:

• Unusually low bid with no exclusions (what did they miss?)
• Long list of exclusions (many items pushed back to GC)
• Unit prices but no lump sum (can’t put in GMP cleanly)
• “Pricing valid for 30 days” — get extensions in writing on long projects

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Step 4: Build the Bid Leveling Sheet

The bid leveling sheet takes every sub bid apart line by line and adjusts each to the same scope basis.

Structure

Line Item	Your Scope	Sub A	Sub B	Sub C
Base bid	—	$A	$B	$C
Exclusion: startup hours	Included	Not included	Included	Not included
ADD: startup (our est.)	—	+$8,500	—	+$8,500
Exclusion: permits	Owner provides	$2,200 extra	$2,200 extra	Not included
ADD: permits (if applicable)	—	—	—	+$2,200
Leveled Total		$A+8,500	$B+2,200	$C+10,700

The leveled total is what you use to compare bids — not the base bid number.

Common Scope Gap Items to Check on Every Bid

• Permits and fees — included or excluded?
• Sales tax on materials (varies by state)
• Startup and commissioning labor hours
• As-built drawings and O&M manuals
• Equipment startup supervision
• Temporary protection (dust walls, temporary HVAC during construction)
• Testing (pressure tests, megger tests, hydrostat tests)
• Warranty — 1 year standard? Callback clause?
• MBE/WBE/DBE requirements if applicable
• Prevailing wage compliance if required

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Step 5: Scope Clarification Calls

After leveling, call the 2–3 lowest bidders:

1. Confirm their understanding of the scope
2. Ask about specific exclusions: “Your bid excludes startup — what would it cost to include?”
3. Confirm schedule availability
4. Get pricing validity extended in writing if needed

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Step 6: Select the Sub and Record the Decision

• Use the leveled total, not the raw bid number
• Consider: schedule availability, bonding capacity, recent project experience, references
• Document selection rationale in the project file
• Never select purely on low price if there are quality or schedule concerns

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Step 7: Apply to the Estimate

• Enter the leveled sub total under the appropriate CSI division
• Note sub’s name, bid date, and key inclusions/exclusions in estimate notes
• This documentation becomes part of the BOE

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Handling Scopes With No Sub Quote

1. Estimate using RSMeans unit prices × your quantities (note “unit price estimate, no sub quote” in BOE)
2. Add 5–10% scope gap contingency allowance on that scope
3. Flag for follow-up sub bidding after award if possible

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Trade-Specific Scope Checklists

Standard checklist items apply to every trade (see Step 4 above). The following checklists add process trade-specific items commonly missed on manufacturing plant projects.

Mechanical — Process Piping

• Pipe material specified (carbon steel, SS 304/316, HDPE, PVC) — not just “process piping”
• Pipe spec (schedule, end connections, fitting standard) included
• Insulation included? Specify type, thickness, cladding material, and who provides jacketing
• Pipe supports — included in mechanical sub or structural sub? Define boundary clearly
• Specialty fittings (strainers, sight glasses, sample points) called out specifically
• Hydrostatic / pressure test included — who provides test water, test pump, isolation blinds?
• Flushing and cleaning after test — included or separate?
• P&ID revision level used to price — document in bid leveling notes
• CIP (Clean-in-Place) piping scope: sanitary fittings (tri-clamp), drainability slope, spray ball connections
• Utility piping (plant air, nitrogen, steam, condensate) — confirm which utilities are in scope

Mechanical — HVAC

• Process HVAC vs. comfort HVAC — scope boundary defined (who owns the process exhaust and supply for production areas?)
• Make-up air unit (MAU) — included or owner-furnished? If included, equipment furnished by whom?
• Exhaust fans and ductwork for process areas — fume/dust rated vs. standard?
• Test, balance, and commissioning (TAB) — explicitly included; who provides TAB report?
• Controls — BAS/DDC integration by HVAC sub or separate controls sub?
• Kitchen/sanitary exhaust if food processing: Type I/II hood, grease duct, fire suppression
• Freeze protection on refrigerated spaces: heating coils, radiant heat, door heaters
• Energy recovery (ERV/HRV) — if specified, confirm included

Electrical — MCC / Switchgear

• MCC furnished by sub or owner-furnished, contractor-installed (OFCI)? Confirm clearly
• Coordination study and arc flash labeling — included or separate?
• Short-circuit and load flow study — who provides? Required before MCC can be labeled
• Conduit and wire to all equipment connections — sub’s scope ends where? At MCC terminals? At equipment junction box?
• Equipment grounds — bonding to structure, grounding electrodes, included?
• Testing and commissioning (megger tests, loop checks) — included; who witnesses?
• Switchgear seismic anchorage if required by jurisdiction or owner spec
• VFD programming and startup support — included for each drive?
• As-built one-line diagrams — included

Electrical — Instrumentation and Controls

• Instrument list revision level used to price
• Field instruments (transmitters, valves, analyzers) — furnished by sub or owner? OFCI?
• Instrument loop drawings (ILDs) / loop tubing — included in scope?
• Control panel fabrication — UL 508A listed panel, sub builds vs. vendor-supplied?
• PLC/SCADA programming — included or separate contract? Define scope of programming (I/O count, screen count)
• Loop checkout and commissioning hours — specify per loop or lump sum
• Calibration of instruments — included? Traceability documentation required?

Industrial Refrigeration (Ammonia — PSM Facilities)

[!warning] PSM scope — additional diligence required Ammonia refrigeration systems with >10,000 lb charge are subject to OSHA PSM (29 CFR 1910.119). Confirm sub has PSM-competent engineering resources and refrigeration mechanic crew.

• PSM compliance documentation — PHA (Process Hazard Analysis), P&IDs, operating procedures — included in sub scope or separate?
• IIAR (International Institute of Ammonia Refrigeration) standards compliance confirmed (IIAR 2, IIAR 5)
• Pressure vessel certification (ASME VIII stamps on vessels and receivers)
• Relief valve sizing and discharge piping per IIAR 2 Section 13
• Leak detection system (ammonia detectors, alarm panel) — included?
• Engine room ventilation — IIAR minimum 0.5 CFM/SF or 30 air changes/hour, whichever is greater; confirm design included
• Emergency pressure control system (high-pressure safety cutouts) — included
• Refrigerant charge quantity and initial fill — included in contract value?
• Startup and commissioning support — defined in hours; IIAR 5 Section 5 startup checklist compliance

CIP / Sanitary Piping (Food & Beverage)

• Sanitary fitting standard specified (3-A, ASME BPE, DIN 11851) — confirm sub’s experience with required standard
• Welder qualifications — ASME BPE or 3-A weld documentation required?
• Weld inspection: borescope inspection of interior welds specified? Who provides report?
• Drainability slope (minimum 1/8” per foot toward drain points) — sub confirms in layout review?
• Dead leg elimination — maximum dead leg length per owner’s SOP or FDA guidance (typically <2× pipe diameter)
• CIP supply/return routing — confirm flow velocities designed for turbulent cleaning (>5 ft/sec)
• Surface finish (Ra) of interior welds — specified (typically 32–63 µin Ra for product contact)
• Passivation after installation — included? Who provides certification documentation?
• Pressure test (water) before passivation — included with documentation