about project
A general contractor preparing a bid for a 220-unit multifamily development required a full plumbing estimate covering domestic water, sanitary, vent, storm drainage, and gas piping systems. The project included six buildings with various unit configurations, multiple piping materials, and extensive underground infrastructure.
Project Scope
- Six multifamily buildings (3–4 stories each)
- 220 total dwelling units
- Full plumbing systems:
- Hot/cold domestic water
- Sanitary and vent systems
- Gas piping distribution
- Underground utilities and site plumbing
- Storm risers and roof drains
- Hot/cold domestic water
All fixtures, fittings, equipment, and accessories included
Client Requirements
The contractor needed an estimate that was:
- Bid-ready and 100% itemized
- Completed within a compressed timeline
- Compatible with their internal estimating format
- Based on accurate pipe sizing and fixture calculations
- Easy to adjust for multiple alternates and unit types
Challenges
- Over 340 combined sheets across architectural, civil, mechanical, and plumbing disciplines
- Five-day deadline, leaving no room for internal review delays
- Multiple fixture types and unit configurations (studio, 1BR, 2BR, specialty units)
- Recent design revisions, requiring careful comparison to avoid overruns
Complex underground routing involving grade beams, site utilities, and tie-ins
Drawing Review & Plan Coordination
Before quantification, our team:
- Cross-checked all discipline sheets for inconsistencies
- Identified conflicting notes, missing dimensions, and ambiguous risers
- Flagged three design discrepancies and notified the client
- Verified fixture schedules, isometrics, and equipment locations
- Compared latest revision clouds to previous sets to avoid quantity duplication
Our Approach
1. Digital Takeoff Execution
Using Bluebeam Revu and PlanSwift, we quantified:
- PEX, copper, and CPVC domestic water lines
- PVC and ABS sanitary/vent systems
- Gas piping runs with BTU load verification
- Underground DWV and water distribution
- All fixtures: tubs, showers, toilets, sinks, washer boxes, hose bibs
All fittings, cleanouts, carriers, valves, traps, hangers, supports
2. Pipe Sizing & Calculation Validation
- Applied local code fixture-unit tables
- Sized mains, risers, and branch lines
- Performed demand and pressure-loss checks
- Adjusted gas pipe sizes based on longest-run method
3. Labor & Production Analysis
Labor hours were determined using:
- Crew productivity rates
- Difficulty factors (ceiling height, congestion, unit layout)
- Terrain conditions for underground runs
- Material handling and staging time
- Equipment needs (trenching, compactors, lifts)
4. Costing & Assemblies
We built complete cost assemblies including:
- Material lists with current regional pricing
- Labor hours for every system
- Equipment, subcontract items, and consumables
Insulation, sleeves, firestopping, and restoration quantities
5. Final Report Delivery
The completed report included:
- A 156-page itemized plumbing estimate
- System-by-system breakdowns
- Unit-type summaries (studio, 1BR, 2BR)
- Alternates for fixture upgrades
- A value-engineering section with cost-saving options
Delivered within 48 hours, ahead of the deadline.
Results
- The GC submitted a competitive bid with complete confidence
- Awarded the project with the estimate being within 3.4% of final contract value
- Vendor negotiations improved copper/fixture pricing by 5%
- The internal estimating team saved over one week of work
- The client requested our support for ongoing monthly progress estimates
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