BIM & Tekla
Tekla vs AutoCAD for Steel Detailing
A practical comparison of Tekla and AutoCAD for steel detailing: model-first versus drawing-first offices, deliverables, skills, file exchange and hybrid setups that actually work.
Offices argue about Tekla versus AutoCAD as if one of them were incorrect. Both can produce a buildable steel package. They fail at different moments. AutoCAD fails when the same beam is drawn on a plan, an elevation and a piece sheet that nobody updates together. A manufacturing modeller such as Tekla Structures fails when the team has no numbering standard, no drawing layout standard, and a reviewer who still expects a 2D approval set the office cannot issue cleanly. The useful comparison is about deliverables and staff, not about which splash screen looks more modern.
AutoCAD remains the lingua franca of 2D engineering drawings. Consultants mark up DWG and PDF. Many PEB approval sets are still authored in CAD because the sheet list is standardised and the geometry is not highly congested. Tekla and similar tools earn their keep when members, bolts and drawings must stay in lockstep, or when NC data is part of the deliverable. Neither tool removes the detailing process. Both still need typicals, a checker and a revision letter before anyone cuts steel.
This article does not inventory menus. Software versions move; the office questions do not. Who authors geometry? Who stamps the record? How do you send a file to a consultant who does not own your modeller? How do LISP Programs still help a hybrid team that plots CAD sheets from or beside a model? Answer those, and the purchase argument usually shrinks to a sized decision rather than a conversion fantasy that tries to finish a live job in a new tool.
Office patterns, not scores
| Situation | Often a better fit | Watch-out |
|---|---|---|
| Standard PEB approval packages, light congestion | AutoCAD (2D) | Keeping piece data consistent by hand |
| Congested industrial steel, NC to the shop | Model-based (e.g. Tekla) | Approval PDFs and consultant DWG exchange |
| Consultant mark-up in DWG, fabricator models | Hybrid | Two geometries claiming to be current |
| Small job, two people, stable typicals | The tool the staff already run well | Buying software instead of writing a standard |
What each tool is actually used for
AutoCAD is a drawing editor. It does not know that a line is a beam unless you treat it as one with layers, blocks and discipline. Tekla is a manufacturing model of parts and assemblies that can create drawings. Comparing them as if they were the same category of program is how demos mislead.
If your contract deliverable is a stamped 2D set and your shop reads plotted sheets, AutoCAD can be the whole authoring world. If your shop reads NC files and your connections are dense, a modeller is doing a different job: it is the parts database from which drawings are a report.
Model-first versus drawing-first offices
Drawing-first means the sheet is the source. Change the sheet, then maybe update other sheets. Model-first means the part is the source. Change the part, then update drawings and lists. Mixing the two without a rule produces duplicate marks and missing clouds.
- State the source of geometry for each project in the kickoff note.
- If model-first, forbid parallel CAD copies of members except as disposable backgrounds.
- If drawing-first, forbid a coordination model that people treat as shop-ready.
- If hybrid, name the sheet types that come from each world.
Deliverables, not features
List what you must issue: approval PDFs, shop PDFs, DWG backgrounds, BOM, bolt lists, NC, IFC for coordination. Then ask which environment produces each item without a second typed copy. Features that do not map to that list are distractions.
| Deliverable | Typical AutoCAD path | Typical model path |
|---|---|---|
| Approval plans/elevations | Direct authoring | Drawings from model views |
| Piece drawings | Manual or semi-automated 2D | Created from parts |
| BOM / bolts | Extract or Excel | Reports from the model |
| NC / DSTV | Usually separate | From the same parts |
| Consultant DWG | Native | Export; check layer mapping |
Staff skills and file exchange
A modeller without trained detailers is a slow CAD. AutoCAD without a standard is a slow modeller with worse consistency. Count the people who can check a connection in the tool you choose, not the people who can orbit a view.
Hybrid offices
Many fabricators model for shop and still produce a 2D approval set the consultant expects. That can work if approval geometry comes from the model or is explicitly allowed to lead the model for a short stage. It fails when a CAD plan and a model plan show different brace locations.
CAD skills remain useful in a model office: cleaning exported DWGs, title-block discipline, and plot hygiene. That is still a place for LISP routines. Do not throw them away because a modeller arrived.
Choosing without a conversion project
Switching authoring tools mid-job is rarely cheaper than finishing in the current tool. Switch between jobs, after a standard and a sample package exist. Pilot one typical product line — a portal frame, a mezzanine — before you declare a company conversion.
A practical workflow
- Write the deliverable list from the contract, not from a sales matrix.
- Mark each item as drawing-first, model-first, or Excel.
- Pick the authoring tool that covers the expensive items without double entry.
- Define the export the other party still needs.
- Run a pilot package through issue and one comment cycle.
- Only then train a second job on the same standard.
Engineering tips
- Judge a modeller by the drawing it produces on your title block, not by the 3D screenshot.
- Judge AutoCAD by mark consistency across ten sheets, not by how fast a line is drawn.
- Keep one numbering system even if two programs are in play.
- Archive native files plus PDF. An export alone is a lossy record.
Common mistakes
Buying software to fix an unwritten standard
If piece marks are already inconsistent in CAD, they will be inconsistent in a model. Write the mark system first.
Assuming the consultant will review in your modeller
Most will mark PDF. Some will mark DWG. Plan for those, then offer a model view as extra.
Exporting DWG once and never checking layers
A spaghetti export becomes the consultant’s background and then your next xref. Map layers on the pilot.
Stopping CAD training on the day the modeller arrives
Sheets, plots and exchanges still exist. Under-trained CAD is a second bottleneck.
Checklist
- Deliverable list written from the contract
- Source of geometry named
- Mark system identical across tools
- PDF layouts match the office title block
- DWG/IFC export path tested with the actual receiver
- Pilot comment cycle completed
- CAD plot hygiene still assigned to someone
Frequently asked questions
Is Tekla always better for steel?
No. It is better when parts, drawings and machine data must stay aligned and the team can run it. It is worse when the product is a simple 2D approval set and nobody can issue drawings from the model to the reviewer’s standard.
Can AutoCAD be used with a 3D model?
Yes. Some offices model simply in CAD or import backgrounds. The limit is manufacturing data and automatic piece drawings, not the ability to draw a line in space.
How long does a switch take?
Count a pilot project, a standard (templates, marks, drawing layouts), and training on that standard. Offices that skip the standard spend the training period inventing it under deadline.
Do we still need checkers if the model produces drawings?
Yes. The model will faithfully report a wrong hole you told it to put there. Checking is still engineering and fabrication review, not a software feature.
Where this leaves the work
Choose the tool that can issue your actual package without typing the same member twice. For many approval-led PEB jobs that remains AutoCAD. For congested fabrication work a modeller often wins. Hybrids work when one geometry is current.
Whatever you pick, the profession is still steel detailing and the shop still reads fabrication drawings. Software is the editor, not the obligation.
This article provides general educational information. Project-specific structural design, calculations and drawings should be reviewed by appropriately qualified engineering professionals and checked against applicable project requirements and standards. StruTools does not replace engineering judgement or professional design review.