“Can we substitute this?” means something different depending on when it's asked. Before a bid closes, the answer runs through an addendum. After the contract is signed, it runs through a submittal. Handle either one the wrong way and the saving disappears into a dispute.
Key takeaways
Both situations get called a “substitution,” and treating them as the same process is the mistake. Before bid close, a contractor proposing an alternate product or method is really asking the owner a question — and questions during the bidding period get answered the same way every other bid inquiry does. CCDC 23 groups “bidder inquiries and issuances of addenda” together for a reason: an inquiry that changes what's biddable has to become an addendum, or it never happened as far as the tender is concerned.
A bidder who emails the consultant asking “can we price Brand B instead of the specified Brand A?” and gets a verbal or private “sure” back has learned nothing that helps the bid. The duty a procuring authority owes every bidder is explicit on this point: “a procuring authority cannot selectively withhold information from some bidders” — which means an answer that changes what's acceptable to bid has to go out to every bidder as an addendum, not stay a private courtesy to whoever asked first. A bidder who prices Brand B on the strength of an informal answer, with no addendum confirming it, has priced something the tender documents still don't allow — and is exposed if the owner simply declines to honour an answer that was never formalized. See how a formal addendum actually binds every bidder equally for the mechanic underneath this.
Where the tender documents allow a base bid plus a priced alternate as separate line items — rather than a straight substitution of the base scope — the same discipline applies twice over, because now two prices have to survive the same addenda review instead of one. An addendum that revises the base specification without touching the alternate, or the reverse, leaves one of the two numbers current and the other quietly stale; a bidder submitting both without re-checking each against every addendum can end up compliant on the base bid and non-compliant on the alternate it also priced, which risks the alternate being struck from consideration even though the base bid stands.
The same principle cuts the other way when the request comes from the owner or consultant's side. A consultant who quietly tells one bidder an alternate is acceptable, without issuing an addendum, has created exactly the selective-disclosure problem the duty of fairness is meant to prevent — and a competing bidder who later learns about it has grounds to challenge the award, not just the bidder who priced the base scope straight and lost. Formalizing every substitution answer as an addendum protects the owner's own process as much as it protects the bidder who asked the question.
Once the contract is signed, the same question — can we use something other than what's specified — routes through a different, and slower, process on purpose. Procore's own definition of a submittal is the clearest description of what that process actually is: “the written and/or physical information provided by a responsible contractor… submitted to the design team for approval of equipment, materials, etc. before they are fabricated and delivered to the project.” Reviewing that submission is the consultant's job under the signed contract — CCDC 2 frames shop drawing and submittal review as part of “the role and authority of the consultant” in administering the work, and the decision gets recorded the same way any shop drawing review is: stamped proceed, revise, or reject. Digitally, Bluebeam's own interactive stamp template ships with exactly that set — Approved, Revise, Rejected — because the record of the decision matters as much as the decision itself. See how the submittal register tracks every one of these requests against a due date and what the review stamp itself is actually certifying. An email from a site superintendent approving a swap on the spot, with nothing routed through that record, is not a substitution that's been accepted under the contract — it's an undocumented instruction that can become a dispute the moment the finished work doesn't match what was specified.
Two processes, not one
Pre-bid alternate: raised as a bidder inquiry, answered by the owner or consultant, formalized as an addendum before close — binding on every bidder, or on none.
Post-award substitution: raised as a submittal, logged against the submittal register, reviewed and stamped by whoever holds contract-administration authority — binding once approved, not once proposed.
What both share: an answer given outside the formal channel — a verbal yes during bidding, a site-level yes after award — binds nobody, however reasonable it felt at the time.
A specified light fixture package prices at $18,400. A distributor offers an alternate fixture, functionally equivalent on paper, at $15,900 — an apparent $2,500 saving. Getting that alternate through the submittal process, though, means a second engineering review of the photometric layout to confirm equivalent light levels, plus revised coordination with the ceiling grid supplier already committed to the original fixture's mounting dimensions — a real cost the estimate has to carry even though no invoice calls it out by name. Priced conservatively at $600 for the extra coordination and review time, the net saving drops to $1,900 — still worth pursuing, but a very different number from the $2,500 the material quote alone suggested. The rule that makes the difference isn't the dollar figure, it's remembering that a substitution's true cost includes what the review and re-coordination take, not just what the new product costs on its own.
Only if the tender documents expressly allow alternates to be submitted with the base bid — many do, in a separate section, precisely so the owner can compare the base price against an alternate without the alternate itself changing what every bidder was required to price. Absent that provision, an unsolicited alternate priced into the base bid risks being treated as a non-compliant deviation from the specified scope, since the owner never disclosed that alternate as an acceptable basis of bid to every bidder equally.
Whoever holds contract-administration authority under the signed agreement — typically the consultant reviewing submittals under CCDC 2, not the site superintendent or project coordinator fielding the question in the field. An acceptance from someone without that authority doesn't bind the owner even if the contractor reasonably believed it did, which is exactly why a verbal field-level yes is worth confirming in writing through the submittal record before ordering or fabricating anything.
Usually just the time spent preparing and reviewing it, unless the contract specifically allocates re-review costs — but a pattern of rejected or poorly-supported substitution requests can affect how quickly future submittals from that contractor get reviewed, since a design team learns which contractors send well-documented requests and which don't. A submittal that clearly shows equivalent performance, not just an equivalent price, tends to move through review faster than one that leaves the reviewer to work that out.
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