DWG, DXF, PDF or IFC: Which File Should You Ask Your Drafter For?

“Just send me the files” is where a lot of drafting jobs go sideways. You get a PDF when you needed something editable, or a DWG your fabricator’s software mangles, or an IFC nobody on the project knows what to do with. Every format encodes a different assumption about what happens next — and asking for the wrong one costs a round trip. Here’s what each format actually is, and which one to ask your drafter for.

The six formats you’ll actually be offered

1. DWG — the working file. AutoCAD’s native format and the default currency of Australian drafting. Fully editable: layers, blocks, dimensions, the lot. Ask for DWG when anyone downstream needs to change the drawing — your engineer, your fabricator, the next consultant. It is the format you want to own at the end of a job, because owning the DWG means owning the drawing.
2. DXF — the interchange file. A published format designed to move CAD data between different programs. If your fabricator runs BricsCAD, DraftSight, or a CNC/laser package rather than AutoCAD, DXF is the safe handover. Slightly less faithful than DWG on exotic objects, dramatically more portable.
3. PDF — the read-only record. What you issue for approval, tender, site and archive. It prints exactly as drawn, it is un-editable by accident, and everyone can open it. It is not a substitute for the DWG — you cannot meaningfully build from a PDF without converting it back, which is a job in itself.
4. IFC — the BIM exchange file. The open standard for exchanging building models between Revit, ArchiCAD, Tekla and coordination tools. IFC carries objects with meaning — this is a wall, that is a duct — not just lines. Ask for IFC when the project runs a federated BIM model and someone is doing clash detection.
5. RVT — the native Revit model. The full BIM authoring file. Only useful to a team also working in Revit, but for them it is the real thing: parametric, editable, complete. On a BIM project, agree upfront whether you are getting the RVT or only an IFC export, because they are not equivalent.
6. STEP — the 3D mechanical file. Neutral 3D solid geometry that moves cleanly between SolidWorks, Inventor, Fusion and CNC toolpaths. This is the one your machinist wants for a manufactured part. STL, its rough cousin, is a mesh good enough for 3D printing but useless for machining.

DWG or DXF? The question people actually mean

They hold much the same content. The difference is ownership versus portability. DWG is Autodesk’s format — richer, more compact, and perfectly faithful if everyone in the chain runs Autodesk software. DXF is the neutral middle ground, designed to be readable by anything, and it is what you send when you do not know what the other side is running. In practice: keep the DWG as your master, hand out DXF when a fabricator or CNC shop asks. If someone offers you “the files” and means PDFs only, that is not a handover — that is a picture of a handover.

What to ask for, by situation

• Council or certifier submission → PDF (issued, stamped, to scale). Keep the DWG for yourself.
• Steel fabricator or workshop → DWG, plus DXF if they run non-Autodesk software. Confirm before issue.
• CNC cutting, laser, waterjet → DXF for 2D profiles; STEP for anything machined in 3D.
• BIM coordination / clash detection → IFC to the coordinator, RVT if the team works natively in Revit.
• 3D printing a prototype → STL or STEP. STEP if the part may still change; STL if it is final.
• End of project, closing the file → all of it. Native (DWG/RVT), neutral (DXF/IFC), and issued PDFs. Sort this in the contract, not at handover.

The trap: only being given PDFs

Plenty of people discover, years later, that they never received an editable file for their own building or product — just PDFs, or worse, paper. Recovering from that means converting the drawings back into CAD, which is real work: someone redraws the geometry, layer by layer, from the flattened image. It is entirely doable — we do it constantly for renovations of older stock and for factories whose original drawings are long gone — but it is a cost you avoid entirely by asking for the native file at the time.

The rule of thumb: issue in PDF, own in DWG. And if you are commissioning drafting work, put the deliverable formats in writing before the job starts.

Common questions

Can a PDF be converted back to DWG? Yes, but it is a redraw, not a button. Automatic PDF-to-DWG tools produce a mess of disconnected line segments on random layers — technically “CAD”, practically unusable. Proper CAD conversion means redrawing with correct layers, blocks and dimensions so the file is genuinely workable.

Which DWG version should I ask for? Specify one your whole chain can open — DWG 2013 or 2018 format is a safe common denominator. A newer file opened in older software will simply refuse.

Do we hand over native files? Yes — every job we do, the client gets the native working files along with the issued PDFs. You paid for the drawing; you should own the drawing. If you need drafting work done or old drawings brought back into CAD, tell us what you have and we’ll come back with a fixed price.