Start at the water source

Irrigation estimates begin at the meter, not at the sprinkler heads. Check the static water pressure and the flow the supply can deliver, because that decides how many heads can run on one zone. A system that looks fine on paper will not work if the supply cannot feed it, and redesigning after the bid is on your dime.

Decide what kind of job this is. A new install, a system expansion, and a repair each scope differently: repairs are diagnosed piece by piece, while installs are designed zone by zone. Note the backflow prevention setup and whether the work touches the potable supply.

Backflow devices and irrigation connections are regulated in many areas. Check your local requirements and include any permit or inspection cost in the estimate.

Lay out zones and count heads

Zones are the unit of an irrigation estimate. Walk the property and sketch the zones: sprays for small turf, rotors for open areas, drip for beds. Each zone needs enough heads to cover its area at the spacing the nozzles are rated for, and the zone's total demand has to fit the water supply you measured.

  • Spray heads for small turf areas and strips
  • Rotors for large open turf
  • Drip lines and emitters for beds and planters
  • One valve per zone, plus a master valve where used
  • Rain sensor and controller inputs where required

Measure pipe runs and trenching

Pipe is priced by the foot, and trenching is priced by the foot and the soil. Measure the main line and lateral runs on your sketch, then add crossings: sidewalks, driveways, and tree roots change trenching from easy to slow. Boring under a driveway is a different line item than trenching a lawn.

Rocky soil, established landscaping, and tight access all add hours. Note what has to be restored after the trench is closed, because sod and bed repair belong in the estimate, not in your margin.

Controller, valves, and wiring

Count the valves and measure the wire runs back to the controller location. Valve manifolds, splices, and the controller itself are material lines, and running wire across the property is labor that estimators routinely undercount.

Price materials at your supplier cost and labor from your crew's pace per task: trenching, laying and gluing pipe, setting heads, wiring valves, and programming the controller. Add overhead and profit on your real costs. The contractor markup guide applies here the same as any trade.

Mistakes that sink irrigation bids

  • Designing zones without measuring water pressure and flow first
  • Undercounting heads and nozzles by sketching from memory
  • Pricing trenching as flat lawn work when crossings and rock exist
  • Forgetting wire, valve boxes, and fittings on the material list
  • Leaving lawn and bed restoration out of the price
  • No line for permits or backflow testing where required

Show the customer a system, not a number

The estimate should read like the system: zones and head counts, pipe and trenching, valves and wiring, the controller, restoration, and the total. State what is excluded, like landscaping repairs beyond the trench line, and how long the price holds.

EstimateBook can draft the line items while you are still on the property: describe the zones by voice or attach photos of the layout, review and edit quantities, prices, and markup, then share a PDF. Treat the draft as a starting point and verify it against your zone sketch before sending.