DfMA gives buyers a way to compare whether shortlisted suppliers connect the building model, piece marks, bolt groups and erection sequence. We coordinate requests for those records; the supplier creates and validates the manufacturing model. The page describes a sourcing review method, not an owned fabrication line.
Model, mill and lift stay on one numbering system, so a purlin bundle on the truck matches the girt line the installer reads on day one.
Our digital handoff request has three gates. Geometry records clear span, eave, ridge, door head and crane rail elevation. Material records proposed steel grade and coating mass with supplier test evidence. Sequence records erection order, bracing and lifting points. A quotation missing the first gate is treated as a budget indication until the supplier and project engineer close the open inputs.
Bay spacing, purlin span and a thermal break at the eave are drawn before nesting. A 24 m workshop and a 42 m warehouse do not inherit each other hole patterns. Aircraft hangar door jambs are modelled as frames, not as a trim item added in the yard.
Heat numbers, weld procedures and coat readings attach to the piece mark. Volumetric boxes and panelized envelopes can share this gate even though their shipping volume differs. The gate does not decide which one is right for the road.
Factory completion is counted as the share of holes, welds and panel cuts done before shipment. It is not counted as a percentage of the construction cost, because foundations, slabs and local MEP remain site work.
Bars depict evidence completeness targets for a buyer review: model geometry, material traceability and installation sequence. They are not measured factory performance, a market survey or a promise for an unreviewed supplier.
Buyers ask which core to put in a cold storage steel structure warehouse and whether to galvanize or paint the frame. Both questions have two defensible answers. The wrong move is to hide the condition that makes one answer fail.
Foam cores are lighter and can post a lower U-value at the same thickness. For a quotation comparison, ask each supplier to state the core type and density, panel thickness in mm and declared U-value in W/(m²·K). Ask for the assembled wall calculation separately, with the panel joints and fixing details identified. Foam needs a fire strategy that looks at the tested assembly, the joints and the openings. Rock wool panels generally weigh more than comparable foam-core panels. Check the supplier’s panel mass, lifting plan and joint details for either core. Rock wool does not make the door or the column fire rated. The supplier comparison records the core, the density if supplied, and the test the buyer is actually citing.
Z275 on purlins and girts suits many inland and mild industrial roofs because the coating is already on the coil. Welds and saw cuts still need repair, or the coating story is incomplete. Painted carbon steel on primary frames allows a specified color and a blast-plus-film system, and it needs a maintenance cycle the owner accepts. A coastal hangar may justify a heavier coat or a duplex system. Copying an inland paint note onto that site is how early rust shows up at the door jamb. Neither option is a permanent corrosion waiver.
A third split is volumetric modular construction against a panelized or stick portal frame. A relocatable building near container size can leave the factory with more of the envelope closed. Transport width, lifting weight and the foundation interface then dominate. A permanent modular construction hall that is really a portal frame on a slab should be permitted as a building, not described as temporary to avoid the energy or accessibility chapter. The selected supplier must state which of those two the drawing is. Calling both by one product name hides the crane and the permit.
How a buyer can check a claim: send the design basis, ask which code combination was used, ask for the weld procedure number, and ask which element the fire minute refers to. A blank design-basis checklist can be reviewed with a qualified professional selected for the project. That review should check units and blank cells. It does not reproduce a full finite-element run and it does not replace the engineer of record. Test data for a sandwich panel, when offered, should name the standard, the specimen build-up and the laboratory. A core brochure without those three items is not treated as a result.
Send span, height, country and whether you are comparing a bolted frame, a welded frame or a volumetric box. The reply opens with the blank cells, not with a slogan.