When a structural engineering firm hands a package of calculation notes and drawings to a subcontractor, the real question is not "can they draw?" but "how will I know it is right before it reaches my own checker, my client or the contractor?" Distance, language and unfamiliar templates make that question sharper. This article describes the routine we apply at Vifatec in Hanoi to every deliverable: a two-step check, where the author is never the last person to look at the work.

Why one pair of eyes is not enough

A calculation note and the drawings that follow it are produced by the same person, from the same model, at the same moment. If an assumption is wrong, or a section was changed in the model but not in the drawing, the author is the person least likely to notice, because he or she sees what was intended rather than what is on the sheet. A second, independent reader breaks that blind spot. Two steps do not replace the responsibility of the design lead; they reduce the number of avoidable errors that reach you.

Step 1: the author works to your rules, not ours

Before production starts we agree on what "right" looks like. You send a brief or a sample task: scope, standards, templates, deadline. We use your templates, layers, title blocks and naming. The first sheets go to you for approval, and only then do we produce the full set. This early approval is the cheapest check of all: it catches a misread convention on three sheets instead of three hundred.

During production the author works from calculation templates, so that loads, load combinations, sections and results are always presented in the same order. Before the file is passed on, the model is audited: element sizes, material properties and supports are checked against the calculation note.

Step 2: an independent checker, not a colleague of convenience

The second step is carried out by an engineer who did not author the deliverable. The checker reads the calculation note and the drawings together. For a reinforced-concrete package, for example, a useful second check typically asks:

  • Do the loads and combinations in the note match the brief and the standard named in it (Eurocodes, French rules or others, as your project requires)?
  • Do the sections and reinforcement on the drawings match the results in the note?
  • Are bar schedules consistent with the drawings, and do the drawings follow your title block and naming?
  • Is the note written so that your own checker can follow it quickly?

Any comment is recorded, answered and closed, rather than corrected silently. Nothing leaves our office before this step is complete.

Traceability: comments, revisions and history

A check is only as useful as its record. Comments and revisions are traceable, and data is archived with its full history. You receive an issue log alongside the files, so that your comments and our answers sit in one place. On projects of any size, a weekly progress report and a shared issue log keep both teams looking at the same list.

Automation for the repetitive part

Production-heavy packages contain many repeated operations: extracting results, building schedules, checking naming. We use in-house Dynamo and Excel/VBA tools for this kind of work. On the Marrakech commercial centre, where we produced reinforcement calculations and drawings in the execution phase as a subcontractor to French structural engineering firms, the production was organised around a project lead, a calculation team leader and a BIM manager. Tasks were allocated by work item and followed against a schedule, and in-house tools sped up the repetitive work. Automation does not replace the checker; it frees the checker's time for the engineering questions.

What you receive

At delivery you get native files, IFC, DWG and PDF, together with the issue log. Files are exchanged through secure channels, after a non-disclosure agreement has been signed. Access is limited to the project team, and data is returned or deleted at your request.

Responsibility stays where it belongs

Vifatec is responsible for the technical quality of what it delivers and corrects errors within its scope. Responsibility towards the project owner and the final sign-off remain with the contracting partner. That is how subcontracted production normally works, and we prefer to state it plainly.

Where we are on formal quality systems

Our internal check is documented and applied to every deliverable. We are working towards a quality management system aligned with ISO 9001, but we are not certified yet, and we are glad to follow your own quality plan and audit requirements instead.

How to try it

The simplest way to judge a two-step check is to see it on a real task. Send us a brief: we will come back with a quote tailored to your scope, standards and deadline, agree your templates, and submit the first sheets for your approval before the full set is produced.

Contact: contact@vifatec.com. We sign your NDA before receiving any data.