3.3 Bid Scope, Addenda, Change Orders & RFIs

3.3 Bid Scope, Addenda, Change Orders & RFIs

Quick Answer: Bid documents define what you are pricing. Addenda change that package before the contract. Change orders change the work after the contract. Review invitation, instructions, agreement, conditions, drawings, specs, and addenda with a supervisor, then use RFIs — question, sheet/spec cite, proposed solution, date needed — when the scope is still unclear.

Task 1.2.2 is learning the scope of contracts by reviewing bid documents with a supervisor. You are not the estimator sitting first chair, but you will lay out whatever was sold. If the bid missed the attic, your overlay will be asked to "just add it" for free.

What sits in the bid set

A complete bid package is more than drawings. Walk the list with your supervisor before you start CAD.

After award, AIA-style general conditions usually define the contract documents as the agreement, conditions, drawings, specifications, addenda, and later modifications (change orders). The invitation and instructions to bidders often drop out of the contract itself. That is why a "see the invitation" note is a weak cite after you are under contract — point to the agreement, the specs, or an addendum instead.

Worked review with a supervisor (30 minutes, not a full estimate):

1. What occupancy and which NFPA standard does Division 21 name?
2. Are engineer fire-protection sheets criteria-only or fully sprinklered?
3. Which addenda numbers are listed on the bid form acknowledgment?
4. Which alternates is the owner likely to accept, and which allowances are in the base number?
5. Where do RFIs go, and who in your shop is allowed to send them?

If you cannot answer those five, you do not yet know the scope of the contract.

Addendum versus change order

An addendum is issued before bids are due, or before the contract is signed, depending on the instructions. It can add a dry-pipe attic, switch NFPA 13 editions, move the FDC, or replace sheet A-101 revision 3 with revision 4. Every bidder is expected to include it. Layout trainees must replace backgrounds and re-read Division 21 after each addendum. Working from the original download is how shops miss entire systems.

A change order is issued after the contract exists. It modifies the work, the price, the time, or all three. Adding twelve heads in a tenant demising wall that was not on the bid drawings is a change, not a courtesy. Trainees do not issue change orders. They flag extra-scope work so the project manager can price it.

Do not call a post-award drawing revision an addendum. Call it what the contract calls it: ASI, bulletin, proposed change, or change-order exhibit. The label controls whether you are still in bid-time or in paid extra work. A clouded beam issued two months after the notice to proceed is not free just because it arrived on an architectural sheet.

Worked example: Bid day is Thursday. Tuesday's Addendum 2 adds a loading-dock canopy with dry pendents and issues A-101 revision 4. You replace the background, add the canopy to the overlay, and tell estimating the head count changed. Six weeks after award, the owner wants those same canopy heads chrome instead of brass. That finish change is a change order (or a change-order proposal), not Addendum 3.

Allowance versus alternate

An allowance is a stipulated sum (or quantity) baked into the contract for work that is not fully defined. Example: "Include an $8,000 allowance for additional sprinklers in future tenant rooms." You draw and track what is spent against that bucket. You do not treat the allowance as free extra profit, and you do not omit the rooms from coordination just because walls are not drawn yet.

An alternate is an optional price on the bid form that the owner may accept. Example: Alternate 1 — add dry-pipe protection in the attic; Alternate 2 — provide chrome pendents in lieu of brass in corridors. If Alternate 1 is not accepted, do not lay out the attic as base scope. If it is accepted, it becomes contract work as if it had always been in the base bid.

Worked example: The bid form lists Base Bid (wet system, occupied floors), Allowance No. 1 ($5,000 for additional heads during tenant improvement), and Alternate A (attic dry system). Addendum 2 adds a loading-dock dry pendant canopy to the base bid. You layout occupied floors plus the dock canopy (base plus addendum). You layout the attic only if Alternate A is marked accepted. You track TI heads against the allowance with a running count so the project manager knows when the bucket is empty.

Unit prices on the bid form (for example $185 per additional pendent, installed) are cousins of allowances. They pre-price extra heads so a later change order has a rate. They are not permission to add heads without documentation.

Design-build layout versus design-bid-build install-from-engineer

Design-bid-build (DBB) in the building sense means an architect and engineers produce a set, contractors bid it, and one contractor installs it. Fire sprinklers are often still performance specified: Division 21 says provide a complete system meeting NFPA 13, and the engineer's fire-protection sheets may be criteria-only (riser location, performance, maybe a schematic). The sprinkler contractor then produces working drawings.

Some DBB projects instead include complete engineer-of-record sprinkler drawings with head locations and pipe sizes. In that case the installing contractor's layout is closer to shop drawings that follow the engineered locations, with coordination shifts documented rather than a from-scratch design.

Design-build layout, as the trade uses the phrase, means the sprinkler firm is responsible for the design documents: hazard, spacing, pipe sizing, hangers, and calculations. Backgrounds come from the architect and structural engineer; the sprinkler overlay is yours. That is the common delegated-design model even when the building contract is design-bid-build.

At trainee depth, the phrase "complete working drawings per NFPA 13" usually includes scaled floor plans showing sprinklers and piping, riser details, a legend, occupancy and hazard notes, ceiling and construction information, water-supply data, and the other working-plan items NFPA 13 lists in its working-plan chapter. You are not expected to recite that entire list here (a later chapter covers working-plan content). You are expected to know that a criteria sheet plus a product spec is not yet a working drawing, and that "complete" is a contract word you verify against both Division 21 and NFPA 13 — not against a verbal "just get some heads on the plan."

If your supervisor says this job is install-from-engineer, your first overlay checks whether the engineered heads clear the current RCP and structural joists. If they do not, that is an RFI or a documented coordination shift, not a silent move of a head 4 feet because it was easier.

RFI anatomy

A request for information (RFI) is how the contractor asks the design professional to resolve missing or conflicting information. Level I trainees draft the technical question; a supervisor usually issues it.

Minimum anatomy:

• Question — one conflict or gap, written so a stranger can understand it
• Sheet / specification reference — exact sheet number, revision, detail, and spec section or paragraph
• Proposed solution — what you think is correct, with a sketch if it helps
• Date needed — when shop drawings freeze or when the fabricator needs an answer

Worked RFI: "Sheet A-201 (rev 4) RCP shows a continuous gypsum soffit 3'-0" wide along grid C. Sheet S-101 (rev 3) shows 18-inch bar joists at 5'-0" on center perpendicular to grid C. Specification 21 13 13 requires quick-response pendents at the finished ceiling. Question: should sprinklers be located under the soffit only, at the deck in the joist channels, or both? Proposed: pendent sprinklers under the soffit at the 9'-0" ceiling, and confirm whether the adjacent 18-inch joist bays require additional heads under obstructed-construction rules. Date needed: 2026-10-03, two weeks before the shop-drawing due date."

That proposed solution is not you deciding the design. It is you helping the reviewer answer faster. An RFI with only "please advise soffit" wastes a week.

Transmittals belong mainly to later correspondence chapters. For this section, know only that a transmittal is the cover sheet that records what was sent (drawings, RFIs, shop drawings), to whom, and on what date. It is not the RFI itself. Do not put the technical question only on the transmittal and leave the RFI form blank.

Close the loop: after the design professional answers, replace backgrounds if a new revision arrived, update the overlay, and tell estimating if the answer added heads, a dry system, or a product upgrade. An answered RFI that nobody posts onto the layout is how shops build the conflict they already paid to resolve.