Planning & documentation
Documenting Steel Building Bid Alternates
Keep steel building bid alternates comparable by documenting changed assemblies, affected trades, acceptance reviews, and base-scope exclusions.
Define the condition and its scope
An alternate changes a defined requirement and should identify every affected interface.
A steel building proposal is a boundary between several businesses: the building-system supplier, concrete contractor, erector, enclosure installer, and trades that complete the occupied space. Cold-formed components may be included in one package and field-installed under another. Comparing the headline amount alone hides these handoffs. Start with the issued scope and give every bidder the same drawings, revision list, delivery assumptions, and request for written exclusions. Keep owner decisions visible beside contractor commitments so that an unresolved preference does not become an assumed inclusion.
References: Project Planning Guide · Commissioning documents: process, contents, and acceptance
Gather the inputs before deciding
Describe the base requirement before evaluating an alternate. Request the proposed product or assembly, the requirement it changes, the affected drawing references, and the bidder's written inclusions and exclusions. Review support, openings, control-layer transitions, installation sequence, maintenance, and compliance documentation as applicable to that alternate. Ask adjacent trades whether their accepted scope changes. Do not treat a catalog statement of similar performance as confirmation of project compatibility. Multiple alternates should each receive their own identifier so the owner can accept one without accidentally accepting another linked assumption.
- Base assembly description
- Proposed alternate assembly
- Adjacent trade effects
- Required acceptance reviews
References: Project Planning Guide · Commissioning documents: process, contents, and acceptance
Set observable handoff deliverables
A roof alternate may change supports, openings, insulation, and installation sequencing.
| Input | Evidence to keep with it | Review status |
|---|---|---|
| Base assembly description | Current base requirement | Identify reviewer and written decision |
| Proposed alternate assembly | Alternate detail and product data | Identify reviewer and written decision |
| Adjacent trade effects | Affected-trade acknowledgment | Identify reviewer and written decision |
Sequence review and release
Route the alternate to the responsible reviewers while the base bid remains intact. Obtain the technical disposition, adjacent-trade effects, and any revised procurement commitments. Summarize the whole change for the owner, including unresolved conditions rather than hiding them behind a favorable price difference. If accepted, issue the required revised documents and purchasing authorization, then confirm which base items are deleted or retained. If rejected, preserve the disposition and proceed with the unchanged base requirement. The supplier must know the final accepted combination before package release.
- Locate base assembly description in the current record.
- Compare proposed alternate assembly with the table's evidence.
- Document the decision: Accept alternates only with documented downstream scope changes.
Worked project coordination example
A bidder offers a different wall assembly. The comparison lists panel, transition, support, and energy-document changes, allowing the owner to evaluate the complete alternate rather than only the panel price difference.
Apply the stated release decision to the case: Accept alternates only with documented downstream scope changes. The responsible team determines acceptance for the actual project and records any condition that still requires resolution.
Keep a closeout record another team can use
Keep an accepted-alternate record linking its identifier, reviewed information, owner decision, affected scopes, and issued revision. Carry the selected assembly into takeoffs, submittals, installation details, and handoff product information. An accepted wall alternate, for example, should not leave the old insulation or opening-transition details in the field set. Preserve rejected options separately so they are not mistakenly ordered later. If an installer proposes another substitution during construction, treat it as a new proposal with its own review rather than extending the previous acceptance to a different product.
For this issue, include affected-trade acknowledgment in the handoff. If review remains pending, identify the dependent work and its owner; do not present the record as a completed technical acceptance.
Common questions
Should alternates be blended into the base bid?
No. Keep the base and each proposed change independently reviewable.
How should base assembly description be documented?
Accept alternates only with documented downstream scope changes. Retain current base requirement and check that the decision reached the team performing the dependent work.
Sources & further reading
Use the current documentation for the exact product and project. Source links do not imply a partnership or endorsement.
- Project Planning Guide U.S. General Services Administration / WBDG
- Commissioning documents: process, contents, and acceptance Whole Building Design Guide
Prepared with AI assistance. Linked references require current project-specific review. How these guides are prepared.
Prepare a supply inquiry
- Record the project drawing or detail and the specified product, profile, or system.
- List the complete configuration, physical units, quantities, and cuts per piece.
- Request current manufacturer documents; confirm compatibility, price, and availability before ordering.
- Obtain the responsible professional's review for loads, code requirements, or installation.