Addendum vs bulletin vs ASI: which is which, and when

Three instruments, three moments

An addendum belongs to bidding. It is issued before the contract exists, to every bidder at once, and the bidders price it. Because they price it, it never produces a change order; it changes what the contract sum will be before there is a contract sum. An ASI belongs to construction and to the architect alone. It is the instruction the owner-contractor agreement lets the architect give without anyone else signing, on the strict condition that it changes neither the price nor the schedule. A bulletin also belongs to construction, and it exists precisely because something does change the price or the schedule: it is the package of revised drawings the contractor prices, and the price becomes a change order.

Two more instruments sit beside these and are worth placing in the same table so the picture is complete: the construction change directive, which orders work to proceed before a price is agreed, and the change order, which is the agreement itself.

The official definitions

The words have definitions, and the definitions are short enough to quote. These are from the AIA documents in force in 2026, as published at aiacontracts.com; the clause numbers are given so a reader can check them against a licensed copy.

• Addenda (A701-2018, Instructions to Bidders, §1.3): “written or graphic instruments issued by the Architect which modify or interpret the Bidding Documents by additions, deletions, clarifications or corrections.” Section 3.4 sets out how they are issued and acknowledged. AIA summary of A701-2018.
• Minor changes in the Work (A201-2017, General Conditions, §7.4): “The Architect may order minor changes in the Work that are consistent with the intent of the Contract Documents and do not involve an adjustment in the Contract Sum or an extension of the Contract Time. The Architect’s order for minor changes shall be in writing.” The written order is the ASI.
• Architect’s Supplemental Instructions (G710-2017): in the AIA’s words, the form “is used by the architect to issue additional instructions or interpretations, or to order minor changes in the work,” and “should not be used to change the contract sum or contract time.” AIA instructions for G710.
• Proposal Request (G709-2018): “used to obtain price quotations required in the negotiation of change orders.” The AIA adds that it “is not a change order or a direction to proceed with the work.” AIA instructions for G709.
• Change Order (A201-2017 §7.2.1): “a written instrument prepared by the Architect and signed by the Owner, Contractor, and Architect stating their agreement upon all of the following: the change in the Work; the amount of the adjustment, if any, in the Contract Sum; and the extent of the adjustment, if any, in the Contract Time.” The form is G701-2017. AIA on change orders.
• Construction Change Directive (A201-2017 §7.3.1): “a written order prepared by the Architect and signed by the Owner and Architect, directing a change in the Work prior to agreement on adjustment, if any, in the Contract Sum or Contract Time, or both.” The form is G714-2017. AIA summary of G714.
• Bulletin: no AIA definition. It is the industry’s word for the package of revised drawings that goes out with a proposal request, and in many offices for the request itself. Because no document defines it, this page does, below.

Addenda: changing the set before anyone has signed

Bidding is the one phase in which the architect can change the drawings and nobody has to be paid for the change, because nobody has committed to a price yet. That is what an addendum is for. A bidder asks a question, the answer changes a detail, and rather than tell one bidder, the architect issues the answer to all of them as a numbered addendum with a date. Each bidder acknowledges every addendum on the bid form, so there is no argument later about who saw what.

An addendum can carry anything: a corrected dimension, a replaced sheet, a new specification section, a changed bid date. The discipline is in the numbering and the distribution. Addendum 3 goes to everyone who received Addendum 2, on the same day, and it says on its face what it changes, sheet by sheet. When the contract is awarded, every addendum is folded into the drawings to make the conformed set, which is the set the contract is signed on.

ASIs: the minor change

A201-2017 §7.4 gives the architect the authority to order minor changes in the work that are consistent with the intent of the contract documents and involve no adjustment in the contract sum or the contract time. The written form of that order is the Architect’s Supplemental Instruction, AIA G710. An ASI is therefore not a request and not a proposal. It is an instruction the contractor is obliged to carry out, and its only limit is the one in the clause: no money, no time.

That limit is what the arguments are about. The architect believes a moved outlet is minor; the electrician has already roughed it in. A201-2017 handles this in the same clause: a contractor who believes an ASI does affect the sum or the time is to say so in writing before carrying it out, because carrying it out is taken as agreement that it does not. The practical consequence for an architect is that an ASI should be issued early, read carefully by the contractor, and converted to a bulletin the moment anyone credibly says it costs something.

A typical ASI package is short: the G710 form with a one-paragraph description, and either a sketch or a revised sheet with the change clouded. The revised sheet gets a new revision number and the revision block names the ASI, so that a sheet’s history reads as a sequence of instruments rather than a sequence of dates.

Proposal request, bulletin, change proposal request: the change that needs a price

The AIA’s instrument for a change that will cost money or time is the Proposal Request, G709-2018, which the AIA describes as “used to obtain price quotations required in the negotiation of change orders” and which “is not a change order or a direction to proceed with the work.” The architect fills it in, describes the change, references the drawings by number and the specifications by section, and sends it to the contractor. The contractor’s priced answer is the change proposal, and if the owner accepts it, the change order follows.

Around that one form the industry uses several words, and they overlap. A bulletin is the practice term for the package of revised drawings that goes with the proposal request, and in many offices for the request itself: Bulletin 3 is both the clouded sheets and the request to price them. A change proposal request, CPR, is the same request under the name some owners and some forms of agreement use, and in those forms it is the owner rather than the architect who issues it. A proposed change order or potential change order, PCO, is the contractor’s or the construction manager’s tracking number for the same change on its way to a change order, though some regions use PCO for the request as well. The project manual usually defines which word the project uses; where it does not, the architect should.

What the package contains is the part worth being precise about, whatever it is called. A cover narrative that says what changed and why, in plain language. A list of every sheet in the package with its new revision number. The sheets themselves, with the changes clouded and a revision triangle in the title block naming the bulletin. And a statement of what the contractor is being asked to do with it, which is almost always to price it and not to build it.

That last line is the one that gets lost. A proposal request is a request for a price, and the AIA says so in the form’s own instructions. The work in it becomes contract work when a change order is signed, or when the owner directs it under a construction change directive. A superintendent who builds from Bulletin 3 before it is priced has built something the contract does not yet contain, and a field office that is still framing from Addendum 2 after Bulletin 3 was priced and signed has built something the contract no longer contains. Both happen, and both are a document-control failure before they are anyone’s fault.

CCD vs change order, briefly

A change order, AIA G701 under A201-2017 §7.2, is the three-party agreement: “signed by the Owner, Contractor, and Architect stating their agreement” on the change, the adjustment to the contract sum and the adjustment to the contract time. A construction change directive, AIA G714 under §7.3, is “directing a change in the Work prior to agreement on adjustment”: the owner and architect sign, the contractor proceeds, and the adjustment is settled afterwards, by agreement or by the method in the clause. Most proposal requests end as change orders. One that is holding up the schedule ends as a CCD first and a change order later. The AIA on the difference.

Reading a revision block

The title block is where all of this is recorded, and reading one correctly is the skill the whole page is about. Each revision to a sheet gets a number in a triangle, in sequence, and a line in the revision block with the date and the instrument: Rev 1, Addendum 2; Rev 2, ASI 03; Rev 3, Bulletin 1. The triangle on the drawing marks where the change is; the line in the block says what caused it. A sheet whose revision block names only dates, with no instruments, is a sheet whose history has to be reconstructed from email.

The sheet index does the same job for the set. It lists every sheet and the revision it is on, so that a reader can tell in one glance whether the A201 in hand is the current one. When the index and the sheet disagree, the sheet has moved on and the index was not updated, and the next question is always which other sheets moved with it.

Which one do I issue?

The three questions, in order.

• Has the contract been signed? No: it is an addendum, to every bidder, numbered and dated. Yes: read on.
• Does the change affect the contract sum or the contract time? No, and it is consistent with the design intent: an ASI on G710. Yes, or you are not sure: a proposal request on G709, with the bulletin package behind it.
• Does the work need to start before the price is agreed? Yes: ask the owner for a construction change directive. No: wait for the change order, and say so on the bulletin cover.