An ASI, or Architect’s Supplemental Instruction, is the architect’s written instruction, interpretation or order for a minor change in the work that does not change the contract sum or the contract time. Many ASIs arrive with revised sheets, and the clouds on those sheets do not always show everything that moved. Drawing Revision Delta, a Windows app from Automata Labs, compares the sheets you are building from with the sheets the ASI issues, lists which sheets changed and where, and lets you step through every change on your own PC.
This guide explains where the ASI sits among the other change documents on a project, why its sheets deserve a full comparison rather than a glance at the clouds, and a repeatable way to check them.
Compare the current set with the sheets an ASI reissues and see every change, clouded or not.
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What is an ASI in construction?
On projects that use AIA contract documents, the ASI is AIA Document G710, Architect’s Supplemental Instructions. The AIA’s summary of G710-2017 says the architect uses it “to issue additional instructions or interpretations, or to order minor changes in the work,” and that G710 “should not be used to change the contract sum or contract time.” The minor changes it covers are authorized under Section 7.4 of AIA Document A201-2017, the general conditions.
The AIA’s instructions for G710 add a practical detail that matters to whoever reviews the drawings: written instructions may be enough, “but drawings or other graphic material should be provided as necessary,” and attached sheets “should be clearly identified, numbered and dated.”
So an ASI can be a single paragraph, or it can be a paragraph plus a handful of reissued sheets. When sheets come with it, those sheets replace what the field is building from.
Not every project uses AIA forms. Owners and design firms often have their own supplemental instruction or bulletin forms. The checking steps below apply to any instrument that reissues sheets.
How is an ASI different from a change order or a CCD?
The difference is money and time. AIA’s own summaries draw the lines this way:
| Document | AIA form | What it does | Changes contract sum or time? |
|---|---|---|---|
| Architect’s Supplemental Instruction (ASI) | G710 | Instructions, interpretations or minor changes | No |
| Proposal Request | G709 | Asks the contractor to price a proposed change | Not by itself |
| Construction Change Directive (CCD) | G714 | Directs a change before sum or time is agreed; the contractor must promptly proceed | Adjustment decided later |
| Change Order | G701 | Records a change all parties agree to | Yes, as agreed |
The G714 summary describes a CCD as a directive “where the owner and contractor have not agreed on proposed changes in the contract sum or contract time,” used for changes which, “if not expeditiously implemented, might delay the project.” The G701 summary says executing a change order “indicates agreement upon all terms of the change, including any changes in the contract sum (or guaranteed maximum price) and contract time.”
The G710 summary also points out that the parties “should use a different form if the Contractor believes that a change in Contract Sum or Contract Time is involved.” That sentence is the reason careful drawing review matters. If an ASI’s revised sheets carry a change that costs money or time, the contractor needs to see it before the work is built, not after.
Why check an ASI’s sheets against the current set?
Because the clouds are drawn by hand. The sheet that comes with an ASI usually has a revision cloud and a delta tag around the change the architect meant to make. Anything else that moved on that sheet, a dimension nudged while the drafter was in the file, a note reworded, a detail reference renumbered, may carry no cloud at all.
Our article on revision clouds and delta tags covers how clouds are meant to work, and our guide to finding unclouded changes on drawings covers why they miss things. For an ASI, the stakes are specific:
- Scope that arrives as “no cost.” An ASI is by definition a no-change-in-sum instrument. A missed change on its sheets can turn into work done for free, or a claim raised after the fact.
- Sheets the field already has. ASI sheets usually replace sheets that are printed, marked up and in use. The superintendent needs to know exactly what is different, not just which sheet numbers were reissued.
- Sheets that are not in the ASI. Sometimes a change to one sheet implies a change to another that was not reissued. A comparison that lists every changed sheet helps you notice when a related sheet did not change.
How do you check the revised sheets in an ASI?
A routine that works for one ASI or for twenty:
| Step | What to do | Why |
|---|---|---|
| 1 | Log the ASI number, date and every attached sheet number | You need the list to confirm nothing is missing |
| 2 | Pull the matching sheets from the set the field is building from | Compare against the current sheets, not the bid set |
| 3 | Compare old and new sheet by sheet | Finds every visual change, clouded or not |
| 4 | Read changed words and dimensions | Small text edits are easy to miss in an overlay |
| 5 | Mark anything that affects cost or time | Raise it before the work is built |
| 6 | Issue the updated sheets with a short change summary | The field sees what changed, not just that something did |
| 7 | File the report with the ASI | Your record of what you checked and when |
Step 2 is where errors creep in. If an earlier ASI or a bulletin already replaced a sheet, the current sheet is that later version. Comparing against the original bid sheet will show every change since bid, which is noise. Our addendum drawing review checklist covers the same discipline during bidding.
Drop the current sheets and the ASI sheets into Drawing Revision Delta and get a changed-sheet list in minutes.
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How does Drawing Revision Delta compare ASI sheets?
Drawing Revision Delta compares an earlier revision with a later one. For an ASI, the earlier revision is the current sheets and the later revision is the ASI’s sheets. According to its Microsoft Store listing, it works like this:
- Pick the two sides. Choose a folder or files for the earlier revision and another for the later one. PDFs, scanned TIFFs and other images are accepted, and multi-page files are split into sheets.
- Sheets pair up by number. Sheets are matched by the sheet number in the title block. When a sheet has no text layer, as with scans and many CAD plots, the app reads the title block with the text recognition built into Windows. You can correct any pair by hand.
- Alignment first. Each pair is aligned for shift, rotation and scale, then corrected locally for the slight stretch that different plotters and scanners introduce.
- Most changed first. The Pairs table shows how much of each sheet changed and sorts the most changed sheets to the top. Sheets that are new in the later set, or missing from it, are listed.
- Three ways to look. Overlay (red only in the earlier revision, blue only in the later one), Blink or Side by side, with revision clouds around each change.
- Changed words in plain terms. Where both PDFs have text, changed words are listed, for example 2x6 to 2x8, so small dimension and note edits are not missed.
- Title block mask. A mask over the title block ignores date and revision-letter edits, so every ASI sheet does not light up just because its issue date moved.
Because an ASI usually reissues only a few sheets, you can compare just those sheets: put the current versions of the attached sheet numbers in one folder and the ASI sheets in the other.
What should you send to the field after an ASI?
Drawing Revision Delta’s exports fit the step 6 and step 7 hand-off:
| Export | What it contains | Use it for |
|---|---|---|
| Clouded PDF | The later sheets, unchanged, with a revision cloud around every change, as PDF markups rather than drawn into the sheets | The set the field prints or opens on a tablet |
| PDF change report | The changed-sheet list, then one section per sheet, with a SHA-256 hash of every input file | Filing with the ASI as a record of what was compared |
| CSV files and PNG snapshots | A sheet summary and every change as rows, plus images | Your ASI log or a quick email to a sub |
The SHA-256 hashes in the report identify exactly which files were compared, which helps months later when someone asks which version of a sheet you reviewed. Our post on comparing two drawing revisions covers the general method in more depth.
Frequently asked questions
Does an ASI change the contract price?
Not under AIA G710. The AIA says G710 should not be used to change the contract sum or contract time. If the contractor believes cost or time is involved, the AIA points to a different form, such as a proposal request, a construction change directive or a change order.
What is the difference between an ASI and an RFI?
An RFI is a question, usually from the contractor. An ASI is the architect’s instruction. An RFI response sometimes leads to an ASI when the answer changes or clarifies the drawings.
Do ASI sheets always have revision clouds?
Usually, by convention, but clouds are drawn by people and can miss changes. Comparing the ASI sheets with the current sheets shows every visual difference, whether or not it is clouded.
Can I compare scanned ASI sheets?
Yes. Drawing Revision Delta accepts scanned TIFFs and other images as well as PDFs, reads title blocks on sheets without text using Windows text recognition, and corrects for the stretch that scanners introduce.
Does anything get uploaded?
No. Drawing Revision Delta runs on your PC, has no account, no sign-in, no telemetry and no ads, and reads only the files and folders you pick.
Try Drawing Revision Delta
Drawing Revision Delta is a one-time purchase in the Microsoft Store with a free trial, so you can run your next ASI through it before you buy. There is no subscription. More detail is on the Drawing Revision Delta product page and in our guide to comparing drawing revisions.
Check every ASI’s sheets against the current set and file a hashed change report with it.
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AIA Contract Documents, A201 and G710 are trademarks of The American Institute of Architects. Drawing Revision Delta is not affiliated with the AIA.
Last updated 21 October 2026. Published by Automata Labs, a software company in Canada.