Units of measure for plumbing
Each piece of plumbing work has its own unit, and keeping them apart is what makes the estimate checkable. These are the units estimators use and how each is measured.
| Item | Unit | How it's measured |
|---|---|---|
| Fixtures | each | Counted by type from the fixture schedule and plans, with carriers and trim. |
| Waste and vent pipe | LF | By size and material, underground and above ground separately. |
| Domestic water pipe | LF | By size and material, with insulation where specified. |
| Fittings and hangers | each or allowance | Counted on detailed takeoffs, or an allowance per foot of pipe. |
| Equipment | each | Water heaters, pumps, interceptors and backflow preventers. |
| Testing | lump sum | Pressure tests, disinfection and inspections per system. |
How estimators take off plumbing
- Count fixtures and equipment. Count every fixture by type and every piece of equipment from the schedules and plans.
- Measure underground piping. Measure waste lines under the slab by size, with trenching and backfill if it's in your scope.
- Measure above-ground piping by system. Waste and vent, hot and cold water, each by size and material, riser by riser.
- Add fittings, hangers and insulation. Count fittings on complex systems or use an allowance on straight runs; add hangers by spacing.
- Price labor. Use crew production per foot of pipe and per fixture set, adjusted for height and access.
Waste factors and order quantities
Waste covers cut-offs, breakage, laps and spillage, and it's added to the net quantity before rounding up to what the supplier sells. These are typical planning figures; your own job history is the better number.
| Item | Factor | Notes |
|---|---|---|
| Pipe | 5 to 10% | Typical planning figure for cut-offs; fittings counted or allowed separately. |
Crew production rates
Labor is quantity divided by production. These rates are per 8-hour crew-day for commercial work, from the same library as the crew-day production estimator: typical mid-range planning values with a low-to-high range, not a promise of output. Crew skill, layout, access and weather move them, and your own crews' records beat any library.
| Activity | Crew | Low | Typical | High | Labor |
|---|---|---|---|---|---|
| PVC DWV underground, 3 to 4 in | 2 plumbers | 120 | 160 LF | 220 | 10.0 hrs per 100 LF |
| Copper water pipe, 3/4 in, with hangers | 2 plumbers | 150 | 190 LF | 250 | 8.4 hrs per 100 LF |
| Set and connect plumbing fixtures | 2 plumbers | 6 | 8 each | 10 | 2.00 hrs per each |
- PVC DWV underground, 3 to 4 in 120 to 220 LF, typical 160
- Copper water pipe, 3/4 in, with hangers 150 to 250 LF, typical 190
- Set and connect plumbing fixtures 6 to 10 each, typical 8
Worked example: 2,400 LF of 3/4 in copper water pipe
The activity is copper water pipe, 3/4 in, with hangers, with a crew of 2 plumbers at the typical rate of 190 LF per crew-day:
- Crew-days: 2,400 LF ÷ 190 = 12.6 crew-days.
- Labor hours: 12.6 crew-days × 2 workers × 8 hours = 202 hours.
- Range: 9.6 crew-days at the high rate to 16 at the low rate, a spread of 6.4 crew-days on the same quantity.
Multiply the labor hours by your burdened hourly cost to price the labor. The spread between the low and high rate is why production is the assumption to check first on a plumbing bid: the same takeoff can carry very different labor. Run your own quantities in the crew-day production estimator, and get the burdened rate from the labor burden calculator.
What drives the cost
- Underground conditions. Rock, water and unsuitable soils make trenching unpredictable; say who carries them.
- Material. Copper, PEX, cast iron and PVC differ in both material and labor per foot.
- Fixture specification. Owner-selected or specialty fixtures, carriers and sensor trim move the fixture cost a lot.
- Site utilities. Where your scope ends outside the building needs to be stated clearly.
Common exclusions and clarifications
A plumbing price is only as good as the scope it describes. These exclusions come from our scope library for plumbing (CSI 22 00 00); list the ones that apply so the GC levels your number fairly.
- Site utilities beyond five feet from the building.
- Utility tap, meter and impact fees.
- Fire sprinkler and fire protection systems.
- Owner-furnished fixtures and equipment beyond final connection.
- Rock excavation, dewatering and removal of unsuitable soils.
- Saw cutting, patching and replacement of existing concrete slabs unless listed as included.
Clarifications that often go with them:
- Scope ends five feet outside the foundation unless noted.
- Owner-furnished fixtures set and connected only.
Pick, edit and export these in the scope inclusions and exclusions library, or load them straight into a proposal with the bid proposal builder.
Free tools for plumbing estimating
- Crew-day production estimator: turn plumbing quantities into crew-days, duration and labor hours with the rates on this page.
- Labor burden calculator: find the true cost of a crew hour, with taxes, insurance and benefits.
- Scope inclusions and exclusions library: pick proposal-ready plumbing exclusions and clarifications.
- Bid proposal builder: send a branded plumbing proposal with the scope language loaded.