Shop drawings are where structural intent becomes something a machine can cut. They're also where a lot of projects quietly lose money, because they sit in the gap between the engineer, the fabricator and the builder — and gaps are where responsibility goes to die.

Engineering says what. Shop drawings say how.

It's a distinction worth being clear about, because clients are often surprised they need both.

  • The engineer's structural drawings — member sizes, loads, locations, design intent. What the steel has to do.
  • Shop drawings — every member itemised, cut lengths, hole positions, cleats, stiffeners, welds, surface treatment, marking and delivery sequence. How the steel gets made and assembled.

An engineer generally doesn't produce the second. A fabricator can't work from the first alone.

The connections are the whole game

Members are easy. What happens where members meet is where steel projects succeed or fail. An undetailed connection doesn't stop the job — it just moves the decision to a workshop or a site, made by whoever is standing there, under time pressure.

Steel is unforgiving because it's pre-made. Timber can be trimmed on site. A beam that arrives with the cleat on the wrong face goes back on the truck. The drawing is the last cheap opportunity to be right.

Tolerance is a real thing

Steel is fabricated to millimetres. Buildings are built to rather less. Somewhere between the two, a connection has to actually go together — with a crane, in wind, through an opening that isn't quite the dimension on the drawing.

Detailers who have never watched that happen draw connections that are geometrically perfect and practically unbuildable. Bolt access, erection sequence, temporary stability while the frame is part-assembled — these are drawing decisions, and they're invisible until someone's standing there at 7am unable to get a spanner in.

Why in-house fabrication changes the drawing

When detailing and fabrication sit in different companies, errors become commercial events — a variation, an argument, a claim. When they sit under one roof, an error is just something the workshop mentions on the way past, and the detail gets better.

That loop has been running for thirty years here. It's the reason our documentation is detailed the way it is across everything we draw, not just the steel — see working drawings and construction support.

Who this is for

Builders and fabricators who need detailing for someone else's design; developers on industrial and commercial projects where structure is the programme; and our own industrial and commercial work, where steel usually is the building. See projects.

Frequently asked

Steel detailing questions.

What is the difference between structural drawings and shop drawings?

Your structural engineer's drawings say what the steel must do — member sizes, loads, where things go. Shop drawings say how it gets made: every member, every hole, every cleat, every weld, cut to length, ready for the workshop floor.

Engineering is design intent. Shop drawings are manufacturing instructions.

Why do steel jobs go wrong?

Usually at the connections. Members are straightforward; what happens where they meet is where the detail either exists or doesn't. If the connection isn't detailed, someone in the workshop or on site decides — and steel that arrives wrong is expensive, because it has already been cut.

The other classic is tolerance. Steel is fabricated to millimetres and buildings are built to something rather less. A detailer who has never watched a beam get craned into a slightly-out opening will draw connections that can't be installed.

Do you fabricate as well as detail?

Yes. We run steel fabrication in-house — which is unusual for a design and drafting studio, and it changes the drawings. When the workshop that makes it is the workshop that read it, the feedback loop is immediate rather than adversarial.

Can you detail steel for someone else's design?

Yes. We detail from an engineer's structural documentation regardless of who drew the architecture, for builders and fabricators as well as our own projects.

Drafting services

The rest of the drafting service.

Each stage answers a different question, for a different assessor.

Ready to start your project?

Site address, sketch, brief, or just a question — we'll respond within one business day.