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Build a schedule and find the critical path

The critical path is the longest chain of dependent tasks from start to finish, and so it sets the earliest possible finish date (GAO). A delay on any task in that chain delays the whole project, so it is where your attention must go.

How

1. List every task from your phasing plan with an estimated duration, including permit decision times and inspection waits.
2. Mark which tasks depend on others. A typical off-grid chain: land purchase, then permits, then access road, then foundations and buried services (water, wastewater, cables), then shell, then roof, then systems, then inspections, then occupancy.
3. Draw the tasks as a simple chart or use free scheduling software and find the longest chain of dependent tasks: that is the critical path.
4. Put each inspection hold point from design-20 in the schedule as a task with its own waiting time.
5. GAO suggests also checking the longest path (the chain that actually drives a key date) because software flags can mislead when you fix dates by hand.
6. Long lead items often sit on it: permit decisions, well drilling slots, battery and inverter deliveries, custom windows.
7. Order long lead items early and book specialist trades well ahead.
8. Add weather allowances to outdoor tasks (see climate notes).
9. Be wary of squeezing the schedule: GAO guidance notes that accelerating work can cut short-term cost but often raises long-term cost.
10. Update the schedule weekly during the build.

Do these first

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Sources

1. Cost Estimating and Assessment Guide: cost estimating challenges. US Government Accountability Office, accessed 2026-11
2. Schedule Assessment Guide: The Critical Path and the Longest Path. US Government Accountability Office, accessed 2026-11

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