Every size and opening
If an opening or a cut-out is in the wrong place on the drawing, it will be in the wrong place on the part. Check each size against the site or the equipment.
British Columbia
British Columbia
WHAT HAPPENS TO YOUR ORDER AFTER YOU SIGN THE DRAWINGS
Each step after you sign turns more of the drawing into metal, so a change costs more the later it comes.
After shop drawing approval, your part is built exactly as the drawings show. It goes from a drawing to a cut sheet to a bent and welded piece. A change while it's still a drawing usually means a revised drawing and a second sign-off. Once the metal is cut, the same change usually means new metal. So check what you're signing, and send any change in writing as early as you can.
Send us the change, and we'll tell you which stage your part is at. The later the stage, the more of it has to be made again.
| Where your part is | What exists so far | What a change means |
|---|---|---|
| Approved, waiting for detailing | Your signed drawing and nothing else | The drawing is revised and comes back to you to approve again |
| Detailed | The flat pieces are worked out and the cutting files are written | The flat pieces and files are redone from the new size |
| Cut | Flat sheet cut to the old size | The cut pieces no longer match, so new sheet is cut |
| Bent and rolled | Formed sides, seams, and collars | The bends are set at the old size, so the piece is usually made again |
| Welded and finished | An assembled part, ground and cleaned | The part is remade, including its finishing |
| Released | Packed and labelled for pickup, delivery, or install | A new part, made from a new approved drawing |
How much of your part a change has to redo
The same change gets bigger at each stage after you sign. The jump comes at the cut.
Approved
Waiting for detailing. A change means a revised drawing
Detailed
Flat pieces and cutting files are redone
Cut
New sheet is cut to the new size
Bent and rolled
The bent piece is usually made again
Welded and finished
The whole part is remade and refinished
Released
A new part from a new approved drawing
HOW MUCH A CHANGE HAS TO REDO
Drawing
Files
Sheet
Part
Part and finish
New part
The cost of a change jumps most once the flat piece for your part is cut from the sheet. Sheet metal is cut flat and then bent, and a new size needs a new flat piece.
Approval turns the drawing into the order, and the part is built to what's on the page, not what was agreed on a call. Check each of these before you sign.
If an opening or a cut-out is in the wrong place on the drawing, it will be in the wrong place on the part. Check each size against the site or the equipment.
Gauge is the thickness of the sheet, and the spec usually sets it. Check that the metal and gauge on the drawing match your spec. The part follows the drawing.
Mark every face that will be on show, and the finish it needs, on the drawing. Any face that isn't marked gets the same finish as a hidden face.
Some parts come in mirror-image pairs. Check that the drawing shows the version your site needs, or the part won't line up once it's installed.
A flange is often formed from the same sheet as the part, while a slip joint slides into the next piece. Confirm how each end connects, because that sets the size of the flat piece.
The count on the drawing is the count that gets made. Check the revision number matches the set your team is working from.
On a job with an engineer or architect, the drawings go to them for review and come back stamped. The stamp says whether work can go ahead. The wording varies, and these are the common ones in Canadian project specifications.
| The stamp says | Can fabrication start? | What to do next |
|---|---|---|
| Reviewed, or No exceptions taken | Yes | Send the stamped set to the fabricator as the approved set |
| Make noted corrections, or Reviewed as modified | Yes, with every note built in | Make sure each note reaches the fabricator's copy before cutting |
| Revise and resubmit | No | Revise the drawings, send them again, and wait for the next stamp |
| Rejected, or Not reviewed | No | Submit new drawings that answer the reasons given |
Once a set is reviewed, it can't be changed again without going back for review. On a smaller job with no consultant, there's no stamp. Your written approval by email, or a signed drawing, does the same job. Either way, the review checks the general design, not your dimensions, and who owns a dimension explains what that means for fit. The time a review adds to your date is covered in when a sheet metal fabrication lead time starts.
On a bigger project, a change comes to you in writing from the owner or the consultant. Under the standard Canadian construction contract (CCDC 2), there are three kinds of change documents. What sets them apart is the price. One has the price agreed, one goes ahead before the price is agreed, and one doesn't change the price at all.
The owner and the contractor have agreed on the change, its price, and its effect on the schedule. If it changes our part, send the revised drawing with it, and we'll put our price for the change in writing.
Commonly used when the change is agreed before the work goes ahead.
The owner tells the contractor to go ahead before the price is agreed. If it changes our part, send it to us with the drawing it affects. We'll still send a written revision with our price before we cut.
Commonly used when a change is urgent and can't wait for a price.
A consultant's instruction that doesn't change the contract price or time, such as a clarification. If it moves a size on our drawing, it's still a change for us. Send it with a marked-up drawing like any other.
Commonly used for clarifying details. Some sites call it a site instruction.
If a change affects a part we're making, send the marked-up drawing and the document behind it together. That way, the size, the reason, and the approval travel as one.
A rectangular-to-round transition is approved, then the engineer moves the round outlet 50 mm to clear a beam. This is an illustration, not a Duct Duct Goose quote.
The drawing is revised and goes back for approval. No metal has been touched, so the change costs a revised drawing and another round of approval.
The flat pieces were cut for the old outlet position, so they're set aside, and a new sheet is cut. The change costs the sheet, the cutting, and a new slot in the schedule.
The transition is complete at the old position. It's made again from the start, and the first one is usually scrap.
The part and the change are the same in all three. What changed the cost was how far along the transition was when the change arrived.
A change can look small when it's one number on a drawing. Once fabrication has started, these ones still mean cutting new metal or redoing work.
| The change | Why it means new work | Usually means |
|---|---|---|
| An opening moved 25 mm | The flat piece is cut with the opening in it | A new flat piece if it's already cut |
| A heavier gauge | Thicker sheet bends differently, so the flat piece changes size | New sheet, and new flat pieces worked out |
| Galvanized to stainless | Stainless is a different metal, welded and finished differently | New material, and the part made again if it's already cut |
| A brushed finish on a face nobody planned to show | Before cutting, the grain direction and protective film are planned around the faces that will show | Extra finishing, and sometimes a remake |
| The part switched to its mirror image | A left-hand and a right-hand version are different parts | A new part if it's already bent |
| An access door or damper added | The part needs an opening and a frame it didn't have | New cutting and assembly, sometimes a new part |
A clarification that doesn't change the part, such as a delivery contact or a label, usually goes ahead without a revision. A change to a size, the metal, hardware, or the finish needs one.
Most remakes after approval come from how a change was sent, not from the change itself. Send it the right way, and the same change stays small.
| What happens | What it leads to | What to do instead |
|---|---|---|
| A change is agreed on a call and never written down | The part is built to the drawing on file, which still shows the old size | Follow every call with a marked-up drawing |
| A set is approved to keep the date, with a fix planned for later | The part is built as drawn, and the later fix becomes a remake | Approve only the parts that won't change, and hold the rest |
| A consultant's notes stay on their copy | The part is built without the correction | Send the stamped set with every note on it |
| The equipment is swapped after approval | The connection no longer lines up with the new unit | Send the new unit's spec sheet the day it changes |
| A revised drawing keeps the old revision number | Nobody can tell which version is the approved one | Give every revised drawing a new number and date |
A change sent before you approve the drawings costs even less. Why quote revisions happen shows how to settle the details while the job is still being priced.
Every change after approval goes through the same steps. They make sure the part we build matches the drawing you signed last.
You send the change in writing. A marked-up drawing or an email with the new size, sent to the person handling your order.
We find your part. We check how far along it is and tell you what the change affects.
We tell you what the change means. A clarification that doesn't change the part usually goes ahead as it is. A change to a size, the metal, hardware, or the finish comes back as a written revision.
You approve the revision. It carries any new price and the new date, and work on that part goes ahead from the new drawing.
We sort out what's already made. If the mistake was ours, we fix or remake it at no charge. If the part was built to the drawing you approved, the rework or remake is priced in the revision.
The same steps apply to custom duct fittings, HVAC ductwork packages, and stainless kitchen work. On a part made again and again, revision control on repeat parts keeps old and new versions apart.
The difference is usually timing and paperwork, not the size of the change.
If a remake will cost more than fixing the part on site, we'll tell you before you approve it. We'd rather point you to the smaller fix, even if it means a smaller order for us.
Each item closes a gap that would otherwise turn a change into a remake. What Duct Duct Goose Needs to Quote Custom Metalwork has the full list for the quote itself.
A change with a date that can't move can raise the price as well. What makes rush fabrication cost more explains why. More guides for getting a job priced and moving sit in Quote-Ready Resources.
Send the marked-up drawing, or a quick note with the new size and the part it belongs to. We'll tell you where that part is, what the change affects, and what it means for your date.
Standard ductwork and fittings price instantly on WebDuct, the online pricing and ordering portal, with a company account. Stainless, grease duct, installs, and other custom work start with a request or a call.
At Duct Duct Goose, we specialize in sheet metal fabrication and stainless steel services for commercial and industrial applications, including HVAC systems, ducts, and custom metalwork. Please note that we do not offer services for automotive-related projects, such as vehicle parts, repairs, or modifications.
