Preconstruction is the project phase between contract award and the start of physical construction. The contractor (typically under a CMAR or design-build delivery, or as paid pre-construction services in DBB) collaborates with the owner and design team on: estimating at multiple design milestones, constructability review, value engineering, schedule development, long-lead procurement strategy, subcontractor pre-qualification, permitting strategy, and budget control.
Well-executed preconstruction reduces total project risk far more than its cost. Constructability comments at 30% drawings cost 1/100th of the same change at 90%. Long-lead orders placed during preconstruction save weeks of total schedule. Pre-qualified sub list ensures bid coverage on every trade. Owner education through preconstruction also reduces change-order conflict during execution because the owner already understands what is in the budget and what is not. The contractors who deliver projects on time and on budget consistently invest heavily in preconstruction.