Reconcile the estimate summary to the detailed takeoff

Why summary agreement is not enough

The summary is a rollup of many decisions. If two detail lines move in opposite directions, the total can look stable while the scope has changed. A reconciliation compares the detail and the summary, not just two totals.

Start with the cost code structure and the detail records that feed each summary line. The goal is to explain every difference, including zero differences that hide offsetting changes.

Reconcile the line structure

Check that each detail line maps to one summary line, that no line is counted twice, and that no active detail line falls outside the summary. Review recent corrections and manual overrides first. A line with a zero value may still carry scope, an assumption, or a note that affects another line.

Treat zero-value lines as records to review, not as automatic deletions. The routine is easier to hand off through cost estimator support.

Test rollups and rounding

Recompute a sample of rollups from the detail, including one high-value line and one line with several components. Check the rounding rule at the detail, subtotal, and summary levels. If the summary uses a different rounding rule from the detail, the difference may look small on one line but grow across many.

Record the rule and the reviewer. The evidence path is described in the takeoff audit trail.

Document the release decision

The reviewer signs off with the detail version, summary version, sample references, and any unresolved difference. An unresolved difference should have an owner and a deadline.

At handoff, the next reviewer should be able to move from a summary line to the supporting detail without guessing which workbook or revision was used. For a broader review frame, use the AACE recommended practices.

Source notes

External reference: AACE International recommended practices. Background sources: GAO cost estimating guide and Census construction spending program.

Frequently Asked Questions