Brownfield Expansion Playbook

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Adding new production lines to an existing manufacturing facility is a brownfield project. It carries a fundamentally different risk profile than greenfield construction and requires a distinct estimating approach.

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Greenfield vs. Brownfield

Factor	Greenfield	Brownfield (Expansion)
Site	Undeveloped land	Existing operating facility
Design flexibility	High — blank canvas	Constrained by existing structure, utilities, layout
Risk profile	More predictable	Higher uncertainty (hidden conditions, as-built accuracy)
Cost vs. greenfield	Higher total, but predictable	Often lower total, but higher risk of overruns
Schedule	Can be faster	Coordination with operations adds complexity
Key estimating challenge	Accurate parametric benchmarking	Site investigation quality and tie-in complexity

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Pre-Estimate Site Investigation

For a brownfield expansion, estimate quality depends on how well you know the existing facility. Before developing a Class 3 or better estimate:

1. Review All As-Built Documentation

• As-built drawings of existing structure (structural, mechanical, electrical)
• Utility plans — existing underground and above-ground utilities
• Original equipment documentation; prior renovation records
• Red flag: As-built drawings are often inaccurate on older facilities. Budget for a field verification survey.

2. Conduct a Conditions Assessment

Walk with the lead estimator, structural engineer, and MEP engineer. Document:

• Existing slab condition (cracks, heaving, oil contamination)
• Electrical capacity: available at nearest panel/switchgear; utility transformer capacity
• Mechanical capacity: compressed air SCFM available; chilled water capacity; gas pressure and volume
• Structural capacity: can existing columns take additional loads? Are existing footings adequate?

3. Geotechnical Investigation

• Obtain borings at the expansion footprint
• Confirm soil bearing capacity
• Check for existing underground structures in the expansion area

4. Hazardous Materials Survey

Older industrial facilities commonly contain ACM (asbestos), LBP (lead-based paint), PCBs in old electrical equipment. Phase I and Phase II environmental assessment before estimating. If hazmat confirmed, abatement cost must be in estimate or explicitly excluded with allowance.

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Tie-Ins — The Highest-Risk Element

Tie-ins are connections between new work and the existing facility. They most frequently cause brownfield overruns because:

1. Existing systems are often not as documented
2. Tie-in work often requires production shutdowns
3. Existing conditions revealed during demolition are unpredictable

Tie-In Categories and Risk

System	Risk Level	Estimating Approach
Structural — connections from new addition to existing wall/column	Medium	Engineer-designed connection; quantify from structural drawings
Slab — saw-cutting existing slab for new drains	Low–Medium	Measure LF of saw cut; confirm existing slab thickness
Electrical — new feeds from existing switchgear; MCC additions	High	Electrical engineer to confirm available capacity; include feeder run + panel work
Compressed air — tap into existing header	Medium	Measure existing header size; confirm capacity with owner’s maintenance team
Chilled water — tap existing CW loop	High	Confirm existing tonnage and available capacity; BTU load calcs from new equipment
Natural gas — extension from existing main	Medium	Gas utility sizing; confirm pressure requirements
Process drains — connect to existing process drain system	Medium	Confirm invert elevations; check existing system capacity
Fire suppression — extension of existing sprinkler system	Medium	Hydraulic calc to confirm existing system can support additional heads
Building envelope — opening in existing wall for expansion joint	High	Structural work; temporary weatherproofing; production protection

Estimating Tie-In Work

• Always include a separate tie-in allowance line item — not buried in each division
• Typical tie-in allowance: 5–10% of process mechanical/electrical scope
• Get mechanical and electrical subs to walk the site before quoting
• Flag all tie-ins explicitly in the BOE as areas of uncertainty

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Phasing and Operational Continuity

Construction must be phased to:

1. Avoid shutting down production unless absolutely necessary
2. Control dust, noise, vibration, and fire risk near food/pharma production
3. Comply with FDA, FSMA, HACCP requirements during construction

Phasing Cost Items to Include in the Estimate

Cost Item	How to Estimate
Temporary dust/contamination wall	LF of partition × $/LF ($15–$40/LF depending on spec)
Temporary overhead door in existing wall	EA × unit cost; note if fire-rated
Weekend/night-shift premium on tie-in labor	Hours × premium (typically 1.5–2.0× day rate)
Temporary re-routing of existing utilities	Allowance; confirmed with owner’s operations team
Food safety compliance during construction	Allowance for additional cleaning, air monitoring
Enhanced security (keep construction workers out of production)	Additional supervision hours

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Applied Workflow: 35,000 SF F&B Expansion, Two New Filling Lines

Phase 1: ROM (Class 5) — Day 1

1. Calculate gross SF: 35,000 SF
2. Apply $/SF from historical F&B plant additions: $180–$280/SF (building only, excluding process equipment)
3. Add process equipment estimate from owner’s preliminary equipment list
4. Add soft costs (design, permits): 10–15%
5. Add Class 5 contingency: 30–40%

Phase 2: Feasibility (Class 4) — Week 3–4

1. Get budgetary vendor quotes for 2 filling lines
2. Apply Lang factor to equipment FOB cost for TIC estimate
3. Develop building cost from preliminary floor plan (assembly-level unit costs)
4. Issue preliminary sub packages to mechanical/electrical; get 30-day budget prices
5. Apply 20–25% contingency

Phase 3: FEED / GMP (Class 3) — Week 6–10

1. QTO from FEED drawings: concrete, structural steel, envelope, site work
2. Issue formal sub packages (3 contractors per major scope)
3. Receive and level sub quotes
4. Price all tie-in scopes as separate allowances
5. Price phasing premiums for night/weekend tie-in work based on owner’s shutdown schedule
6. Build risk register (6–10 specific site/scope risks); calculate risk-based contingency
7. Assemble GMP proposal with complete BOE

Phase 4: Construction

1. Establish SOV and first pay application
2. Track EVM monthly
3. Process change orders formally
4. Coordinate production shutdowns for tie-in work with plant operations (written shutdown schedule)
5. Monitor contingency consumption vs. risk register

Phase 5: Closeout

1. Final cost reconciliation: actual vs. GMP by CSI division
2. Capture $/SF, $/ton, $/LF final actuals for historical cost library
3. Document lessons learned — especially tie-in surprises