Direct Answer
An RFI response triggers a change order when the engineer's clarification requires fabricating more material than the original contract scope, upgrading section sizes, changing connection types, or performing additional engineering. If the RFI simply clarifies something ambiguous without adding scope, it typically does not trigger a change order — but you should review the original contract documents to confirm the work was not already included.
Full Explanation
The threshold is: did the design change add cost? If an RFI asked 'what size is this column splice plate?' and the answer is '3/4" × 8" × 12" A36 plate' — and that plate was already in your BOM estimate — no change order. But if the answer is '1-1/2" × 12" × 18" A572 Gr 50 plate with 4 bolts added that were not on the original drawings,' you have a change. Document the original contract assumption (what was in your BOM) versus the new requirement, and submit a COP.
What This Means for Your Shop
Train your project managers to review every RFI response against the original drawing set and BOM. The gap between the original scope and the RFI-revised scope is your change order. Many fabricators miss this review step and absorb scope growth.
Common Mistakes
Assuming that because an RFI was a 'clarification,' it has no cost impact. Clarifications that change member sizes, add members, or change connection types always have cost impacts — they just have to be identified quickly.
Recommended Process
Within 24 hours of receiving an RFI response, have your estimator or detailer compare the response to the original drawings. If scope changed, issue a written notice and COP to the GC within 5 days.