Worked example ยท fictional quantities
Follow one revision through a material record
This example demonstrates an information check. The members and lengths are invented; no design capacity or completed client outcome is implied.
Assume a preliminary list contains four W18X35 beams, each 20 feet long. The designation's nominal linear weight is 35 lb/ft, as shown in the AISC-derived W18X35 reference. The starting list therefore contains 80 feet and 2,800 pounds of nominal member weight.
Illustrative revision delta using nominal member lengths| Issue | Recorded members | Total length | Nominal weight |
|---|
| A | Four beams at 20 ft | 80 ft | 2,800 lb |
| B | Two beams at 20 ft; two at 21 ft | 82 ft | 2,870 lb |
| Difference | Two affected beam records | +2 ft | +70 lb |
The arithmetic is only one check. A useful revision record also identifies the two affected marks, the drawing issue authorizing the change, whether any material was already ordered or cut, and which lists or sheets need to be superseded. Connection material, fabrication allowances, coatings, procurement lengths, and actual shipping weight are outside this simplified calculation.
Source record
Keep the original list and revised issue separately identifiable. Record the source sheet or response that establishes the new length; do not overwrite the source trail with an unexplained total.
Review record
Compare changed quantities and lengths, then inspect related connections, references, and scope holds under the project's review process. A small weight difference does not mean the change has little coordination impact.
Handoff record
State the issue, affected marks, superseded files, unresolved items, and recipient. Keep nominal takeoff quantities distinct from the purchasing or cutting decisions that follow them.
You can enter this fictional list in the material takeoff, save issue snapshots in a project dashboard, and assemble the chosen records in a handoff package. The process page explains where accountable review belongs.