What affects the cost of a steel structure?

The material share of the price depends mainly on the amount of steel, that is, the weight of the structure. The common grades S235 and S355 are readily available; higher-strength grades are less often in stock and can take longer to source. The same goes for sections: standard beams, hollow sections and plate are easier to get than unusual sizes.

Where the design allows it, using fewer different sections and plate thicknesses helps keep the price down: the material is easier to source and there are fewer offcuts.

Labour is often the largest part of the price. Every part has to be cut or sawn, every hole made, every connection fitted and welded. So the number of parts, the number of holes and cuts, the length and size of the welds, and whether full-penetration welds are needed or fillet welds will do, all affect the price.

Bent and rolled parts add steps. Tight tolerances call for more careful fit-up and measuring. If a tolerance doesn't matter for how the structure works, it is worth not specifying it tighter than needed.

For load-bearing steel structures the execution class under EN 1090-2 (EXC1 to EXC4) sets how strict the requirements for welding, inspection and documentation are. The higher the class, the more weld inspection, material traceability and paperwork, and the more work. Where no execution class is specified, EXC2 applies.

Put the execution class on the drawing or in the request. That way every supplier prices the same requirement and the quotes can be compared.

Surface protection can be a noticeable part of the price. For painting, the price depends on surface preparation (usually abrasive blast cleaning), the paint system, the number of coats and the total film thickness. These follow from the environment's corrosivity category and the durability required under EN ISO 12944. Fire-protective coatings are thicker and cost more than a standard paint system.

The price of hot-dip galvanizing usually depends on the weight of steel galvanized, plus transport of the parts to the galvanizing plant and back. The guide galvanizing or painting explains when each one suits.

Every order carries work that doesn't depend on quantity: working through the drawings, preparing production, making jigs and setting up. The more identical parts, the smaller that share in the price of each one. Repeated details and uniform connections cost less than a different solution in every place.

Very large and heavy parts need lifting equipment and space, and turning and painting them takes longer. The choice of truck also depends on the length and weight of the pieces. If a large structure can be split into transportable sections with simple site connections, that can be cheaper overall.

The more complete the drawing, the more accurate the price. If something is missing, the fabricator has to either ask or allow a margin. A short deadline can mean overtime or rescheduling other work. The guide how to prepare drawings for a quote lists what to put on the drawing.

You get the most accurate quote by sending drawings with quantities, steel grade, surface protection and execution class through the quote form. See also what we build: special metal structures and construction structures.