Contractor involvement during design (Early Contractor Involvement / Design-Build) provides cost reality and constructability input at the point where design decisions are made — when changes are free — rather than after CDs are complete, when changes cost weeks and money. A contractor reviewing SD drawings can identify budget misalignments before the design is advanced. A contractor reviewing DD drawings can identify structural elements that are more expensive than alternatives, MEP routing conflicts with structural drawings, window specifications that don’t meet IECC Zone 5/6 compliance, and construction details that would produce field complications. The same information discovered after CDs are complete generates redesign fees, permit resubmittal delays, and schedule impacts. The industry’s cost-overrun epidemic is largely a coordination failure between designers who design and contractors who build, operating in sequence rather than in parallel.