Scheduling

How to schedule subcontractors

Put the schedule in the subcontract, give each sub written notice with enough lead time to staff the job, confirm manpower in the weekly meeting, and only call them in when their area and materials are truly ready.

Two construction professionals review paper plans beside a tablet at a jobsite workbench.
Plan reviews connect field conditions, drawings, and the next decisions on a job. AI-generated illustration.

To schedule subcontractors well, tie each sub's work to the project schedule in the subcontract, share the schedule with their dates and durations before they sign, give written notice to mobilize with the lead time the subcontract sets, confirm crew size every week in the look-ahead meeting, and only call a sub in when the area, materials, and approvals they need are ready. Most no-shows are not laziness. They are a sub who got a vague text, saw a half-ready area last time, and put the crew on another GC's job.

Subs run several jobs at once. They give their crews to the general contractor whose schedule they trust. Your job is to be that GC.

How to schedule subcontractors in 7 steps

  1. Ask for durations and crew size at bid time. When you level sub bids, ask each bidder how many people, how many days, and what lead time they need. A low bid with a crew of two on a six-week scope is a schedule problem, not a bargain.
  2. Write the schedule into the subcontract. Attach the current schedule as an exhibit and state that the sub must perform in line with it and its updates. Include the notice period for mobilization, required manpower, and what happens if they fall behind. What to include in a subcontract agreement covers the clauses.
  3. Build sub input into the master schedule. Use each sub's durations, then review the sequence with them before you baseline. Subs spot conflicts you will miss, like the sprinkler fitter who needs the ductwork in first.
  4. Give written notice to mobilize. Send a dated notice with the start date, area, scope, and site contact. Send it with the lead time the subcontract requires, and earlier if you can. Follow up by phone, but keep the written record.
  5. Confirm readiness before the call-in. Walk the area 2 or 3 days before the sub arrives. Is the previous trade done? Is material on site or confirmed? Are inspections passed and submittals approved? If not, move the date and tell the sub right away.
  6. Manage the week in the look-ahead meeting. Every sub foreman confirms manpower and dates for the next three weeks. Use a three-week look-ahead so conflicts surface early.
  7. Track performance and act fast. Compare planned manpower to actual headcount from the daily log. If a sub is short two days in a row, call their office the same day, then follow the subcontract's notice process in writing if it continues.

What a good call-in notice includes

  • Job name and address, and the gate or entrance to use.
  • Start date and the expected duration for this mobilization.
  • Exact area or rooms ready for them, and what the previous trade left.
  • Required manpower per the subcontract or the agreed look-ahead.
  • Material status: delivered, staged, or theirs to bring.
  • Site contact, work hours, and any site rules such as badge or safety orientation.
  • Open items that affect them, like an outstanding RFI or a pending inspection.

Worked example: scheduling subs on an office TI

Say a GC is running a 9,000 SF office tenant improvement. The subcontracts require 10 working days notice to mobilize. Framing starts week 2. Here is how the PM schedules the next wave of subs.

Example: call-in plan for the rough-in trades
SubPlanned startNotice sentReadiness checkCrew confirmed
PlumberWeek 3, MondayWeek 1, MondayRestroom walls framed by end of week 23 people
ElectricianWeek 3, WednesdayWeek 1, WednesdayEast half framed, panel location set4 people
MechanicalWeek 3, MondayWeek 1, MondayDuct delivery confirmed for week 33 people
Fire sprinklerWeek 4, MondayWeek 2, MondayShop drawings approved2 people
Low voltageWeek 4, WednesdayWeek 2, WednesdayElectrical rough substantially done2 people

On the Thursday of week 2, the super walks the floor. Framing is done in the restroom core and the east half, but the west half is two days behind. Instead of letting the plumber and electrician show up to half a floor, the PM calls both: plumber starts Monday as planned in the core, electrician starts Wednesday on the east half only, and west half starts the following Monday. The sprinkler shop drawings are still at the architect, so the PM sends a written update to the sprinkler sub the same day pushing their start a week, and escalates the review. Nobody arrives to a site they cannot work.

How to handle a sub who will not show up or keep up

First, find out why. Is your area really ready? Are they waiting on payment, a change order, or an answer? If the problem is on your side, fix it. If it is theirs, follow the subcontract. Most subcontracts require a written notice to cure, a set number of days to fix the problem, and then allow the GC to supplement the crew or terminate for default and charge the cost. Keep the daily logs, manpower counts, and notices. See how to terminate a subcontractor properly before taking that step.

Payment and paperwork are part of the schedule

A sub who has not been paid for last month, or whose change order has sat unsigned for six weeks, will quietly move crews to a job that pays. That shows up as thin manpower, not as an argument. Before a big push, check that pay applications are current and open change orders are moving. The paperwork can block the start too: an expired certificate of insurance or a missing safety orientation can keep a crew at the gate on day one. Clear those items when you send the notice to mobilize, not when the truck arrives. A clean, fast-paying job is the cheapest scheduling tool a GC has.

Mistakes to avoid

  1. Calling subs in by text with no written notice or date.
  2. Calling them in before the area is ready to keep them on the hook. It burns trust fast.
  3. Signing subcontracts without the schedule attached, so dates are not enforceable.
  4. Ignoring manpower until the job is already late.
  5. Stacking three trades in the same room on the same day.
  6. Changing the sequence without telling the subs it affects.

Templates, terms, and tools

Use the subcontractor scope of work template so durations and manpower are part of the scope, and the three-week look-ahead template for weekly coordination. Related terms: subcontract, mobilization, and cure notice. Also see how to sequence trades on a construction project and how to manage subcontractors on the job site.

Smart Business Automator tracks each subcontractor by job, including insurance status and open items, so the PM can see before a call-in whether a sub is cleared to work and what they are waiting on. See construction workflow automation.

Frequently asked questions

How much notice should I give a subcontractor to start?

Whatever the subcontract says, and more when you can. Put a specific notice period in the subcontract so both sides know the rule, and confirm dates in the weekly look-ahead well before the formal notice.

Should subcontractors get the full project schedule?

Yes. Give them the full schedule or at least every activity that affects their work, plus updates. Subs plan crews across several jobs, and they cannot do that from a single start date.

What if a subcontractor has a conflict with another job?

Find out early, ideally in the look-ahead meeting. Agree on minimum manpower in writing. If they still cannot staff your job, follow the subcontract's notice and cure process and keep records of the shortfall.

Who schedules subcontractors, the PM or the superintendent?

Usually both. The PM handles the subcontract, formal notices, and procurement. The superintendent sets day-to-day sequence and checks that areas are ready.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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