The Addendum Review Process
When an addendum is received, the first step is a complete review against the current model — not just reading the addendum in isolation. Every addendum change must be mapped to specific members, drawings, and connections currently in the model. Common impacts: member size changes that cascade through connection designs; plan revisions that shift columns or beams affecting multiple adjacent members; specification changes that affect bolt grades, weld procedures, or surface preparation requirements for all drawings in progress.
Documenting Addendum Impacts
Before making any model changes, document the full scope of the addendum's impact in writing and present it to the fabricator PM. If the addendum causes changes to members already modeled or drawn, that is a scope addition — potentially a change order. If changes are made without documenting the addendum's impact, the cost of those changes is absorbed invisibly into the base contract and the fabricator loses the opportunity to recover them through the GC.
Model Update Sequencing
Update the model from the most fundamental elements outward: columns and primary members first, then secondary members, then connections. Do not attempt to update connections before the framing geometry is finalized — connection geometry depends on member sizes and locations. After the model is updated, regenerate all affected drawings and issue them as a new revision, with revision clouds showing the addendum-driven changes. The revision description should reference the addendum number.
Specification Changes in Addenda
Not all addendum impacts are geometric. Specification addenda — those modifying Division 05 or referenced standards — can affect hundreds of drawings simultaneously. A specification addendum changing bolt grades from A325 to A490 requires updating the general notes, every connection callout, and every bolt list in the entire drawing set. A change from SSPC-SP6 to SSPC-SP10 surface preparation changes paint-area report requirements. These changes are less visible than member revisions but equally important. Review every addendum against the project specification as well as the drawings.
Tracking Addenda in the Model and Document Register
Every addendum should be entered into the project's document register with: its number, issue date, the drawing or specification sections it modifies, and the model objects affected. This register becomes the audit trail that demonstrates all addenda were incorporated and that any items missed were documented as pending. When addenda arrive in rapid succession — as is common in the final weeks before IFC issuance — the register prevents conflicts between addenda and ensures the model reflects the cumulative design intent, not just the most recent change.
- Addendum number and issue date recorded in document register
- Affected drawings and model objects identified before any changes are made
- Change-order notice issued to fabricator if addendum drives additional scope
- Model updated in dependency order — framing first, connections second
- Revised drawings issued with revision clouds and addendum reference in the title block note
Addenda Issued After Fabrication Has Started
The most difficult addendum scenario is one that arrives after a member has already been fabricated. The first question is always: does this addendum affect the already-fabricated member? If yes, evaluate the options: rework in the shop, field modification, or EOR acceptance of the as-fabricated condition. Document the conflict in a formal RFI or change-order notice before proceeding with any modification. The cost of addressing a post-fabrication addendum impact is almost always compensable — but only if it is documented promptly.