Metalwork is one of the last trades to be fully specified and one of the first to show if the design hasn’t been thought through. Staircases, balustrades, cladding and gates all require a level of dimensional accuracy that exposes vague drawings fast.
This is a practical guide on what we need from a set of documents — and where we regularly see projects slow down when that information isn’t there.
Start with the connection details
The most common source of delay isn’t the metalwork itself — it’s the connection points. How a stringer connects to a concrete slab, how a post base plates into a timber substrate, how a fascia panel returns around a corner — these need to be resolved before fabrication starts, not during it.
If the structural engineer and the metalwork fabricator aren’t looking at the same drawing at the same time, someone will make an assumption. In our experience, those assumptions are expensive to fix on site.
Material and finish should be confirmed together
Architects often specify the material (e.g. stainless steel, mild steel, brass) without locking in the finish at the same time. These decisions interact. Brushed 316 stainless behaves very differently to a fine-ground finish under the same light.
We encourage architects to confirm both material and finish before we price. It’s a meaningful variable in cost, and changing it after fabrication has started can be expensive.
Tolerances matter more than most specs acknowledge
Architectural drawings typically work to 1mm tolerance. For most metalwork that’s fine. For folded sheet metal panels with long return edges, laser-cut decorative screens, or anything that needs to align flush with an adjacent trade, you’ll want to discuss tolerance with your fabricator early.
We can hold very tight tolerances on our laser and press brake, but that’s only useful if the tolerances in the drawings reflect what’s achievable in the build.
What to include in a metalwork specification
At a minimum, we need:
- Dimensioned drawings with all connection points noted
- Material specification (grade, thickness, profile)
- Finish specification (include reference samples or NCS/RAL codes where applicable)
- Any surface treatment requirements (powder coat, anodise, patination, or protection for exposure conditions)
- Installation notes — whether supply-only or supply-and-install
If you’re working from a concept and need us to assist with the technical development, we’re happy to do that. We model everything in Autodesk Inventor before we cut anything. But that process takes time, and it should be factored into the programme.
The earlier, the better
We work on projects that are booked months in advance. Lead time on bespoke architectural metalwork is typically eight to fourteen weeks from signed approval.
If you’re specifying metalwork for a project that breaks ground in six months, now is the right time to get a fabricator involved.