A drawing is not a picture: it is a document with a state
A drawing issued for review binds nobody. One issued for construction does, and whoever builds something else answers for it. The geometry can be identical; what changes is the commitment.
| Issue state | What it means | Can you price from it? |
|---|---|---|
| For review or comment |
Marks are expected on it. It is still being argued about | Not firm. An order of magnitude at most |
| For coordination | Goes to the other disciplines to be cross-checked. The scheme should be settled | No. Its own author does not consider it settled yet |
| For permit | Satisfies what the authority requires. Careful: it may lack construction detail | With care. Information the site needs is missing |
| For bid | This is the priced set. Anything asked here is answered by addendum | Yes. That is exactly what it is for |
| For construction | The governing set. From here on, every change leaves a trail and usually an invoice | Yes, and it is what gets built |
The right question about a drawing is never «is this up to date?». It is «what was it issued for, and when?».
The three marks of a revision
When a drawing is reissued, being new is not enough. It has to say what changed, where and why. There is a language for that, it is essentially the same everywhere, and it is three marks that only work together.
The rules almost nobody writes down
- Cloud only what changed, not the whole sheet. A sheet covered in clouds is a sheet nobody will review.
- Clouds from the previous revision get deleted. If they pile up, by revision four nothing is legible.
- The description has to give the reason, not the obvious. «General update» is useless; «wall at grid C changed per RFI 042» is not.
- Many offices use letters before issuing for construction (A, B, C) and numbers after. It is not universal, but when you see it you know letters are design and numbers are construction.
- The superseded sheet is withdrawn. If two versions circulate at once, somebody is building the wrong one and you will find out too late.
Addendum, ASI, change order: what each one is
Every document that modifies a project falls into one of two worlds, and the line between them is contract signature. Confusing them means confusing who pays.
| Document | When | What it does | Does it change the price? |
|---|---|---|---|
| Addendum | Before signing | Modifies the bid documents while pricing is still open. Every bidder receives it | No: it is priced in. If you missed it, you pay the difference |
| RFI | After | A question to the designer. Its answer can trigger everything else | On its own, no |
| Supplemental instruction | After | Clarifies without changing scope | It should not. If extra work is slipped in, say so in writing the same day |
| Proposal request | After | You are asked to price a change. Not approved yet | Not yet. It is a quotation |
| Change order | After | Signed by both parties. It amends the contract | Yes, and the time as well if applicable |
| Construction change directive | After | The owner directs the work before the price is agreed | Yes, but settled later. Keep records of everything |
Traceability: where every number came from
All of the above exists for this. A quantity, a price or a date is only as good as your ability to reconstruct where it came from. And reconstructing means answering three things without hesitating: which sheet, which revision and which date.
Somebody points at any number in your estimate and you have to reach the drawing in under a minute. If you cannot, you do not have traceability. You have memory.
What to do when a new revision lands
This is where more money is lost than in any measurement error. Revision 3 of sheet A-201 arrives. The correct sequence is:
- Read the cloud and the block, not the whole sheet. The drawing already tells you what changed; there is no need to rediscover it.
- Identify which take-offs touch that area. This is where measuring by location pays for itself: if you measured by list, you have to check everything.
- Measure only the difference. You do not redo the whole take-off; you measure the delta and record which revision it is against.
- See which divisions and activities move, and whether any of them was already billed.
- Decide whether it is a scope change, and if it is, raise the paperwork the same day.
Frequently asked questions
What is a revision cloud?
The wavy line enclosing exactly the area of the drawing that changed since the previous issue. It always travels with a delta triangle carrying the revision number, so you know which revision it belongs to, and its reason is spelled out in the revision block in the title block.
What is the difference between an addendum and a change order?
An addendum comes before contract signature: it modifies the bid documents while pricing is still open, every bidder receives it, and it is priced in — it costs nothing extra. A change order comes after: it amends a signed contract, is signed by both parties, and does change the price and, where applicable, the time.
Can you price from a drawing issued for coordination?
Not firmly. Its own author does not consider that sheet settled: it is circulating so the other disciplines can cross-check it. The issue state is printed on the sheet itself, and it is the first thing to read before measuring anything.
Why do some revisions use letters and others numbers?
It is an office convention rather than a universal standard, but a very widespread one: letters (A, B, C) during design, before issue for construction, and numbers (1, 2, 3) after. When you see one, you know which side of that line the document sits on.
What happens if two revisions of the same sheet are in circulation?
Somebody is building the wrong one. That is why a superseded sheet is actively withdrawn rather than left around «just in case»: the cost of the old version being available is always higher than the cost of losing it.