Why alternates need their own record
An alternate is a defined change to the base offer, not a second version of the whole estimate. If the team edits base quantities to test an alternate, the base offer can drift without a visible decision. The alternate record should identify the bid form item, the scope included, the quantity basis, the add or deduct direction, and the person who approved the mapping.
Map the bid form to the takeoff
Start with the owner's bid form and copy the alternate labels exactly. Then link each label to the estimate lines that support it. Do not rename an alternate to match an internal cost code until the original label is preserved.
A unit quantity alternate needs a clear basis, such as a count of fixtures or a measured area. A lump-sum alternate needs a scope narrative that says what is included and what remains in the base. The routine is easier to hand off through bid coordinator support.
Test the add and deduct direction
The reviewer checks the sign, the base condition, and the quantity. An alternate that adds a canopy should not remove the base canopy line unless the bid documents say the base excludes it. Run a small reconciliation: base estimate, alternate additions, alternate deductions, and the resulting offer.
Differences should be explained by scope, not by spreadsheet order. The evidence path is described in the bid package coverage map.
Protect the base offer at release
Freeze the base estimate before the alternate review begins. If the alternate exposes a base scope error, record the correction as a separate change with its own evidence and approval. The bid-close note should list every alternate, its status, and the exact bid form label.
That note lets a reviewer reproduce the offer without reopening every takeoff file. 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.
| Bid form item | Estimate link | Release check |
|---|---|---|
| Add alternate | Added scope and quantity basis | Confirm the base does not already include it |
| Deduct alternate | Removed scope and base condition | Confirm the deduction is supported by documents |
| Unit quantity alternate | Measured count or area | Confirm the unit and rounding rule |
