How Do Contractors Maintain Cost Accuracy When Design Drawings Are Still Evolving?

[Jackson_Poole]

I’m currently involved in a building project where design drawings are being issued in stages, and several details are still under development. The challenge we’re facing is keeping cost projections reliable while quantities and specifications continue to change between revisions. Even small drawing updates are affecting material counts, trade scope, and procurement planning.

I’m trying to understand what processes experienced contractors use to keep budgets aligned during these evolving design phases. Some teams recommend relying on estimating services for construction that can continuously update quantities and cost impacts with each revision, helping decision-makers stay aware of real-time budget shifts before tender.

For those who’ve worked on fast-track or design-develop projects, how do you manage estimate accuracy while drawings are still progressing? Any workflows or controls that have proven effective?