Design deliverables: calculations and drawings

The deliverables chain

A pre-engineered building moves from enquiry to site through a defined sequence of design deliverables. Each one serves a different reader – owner, architect, engineer of record, building authority, foundation contractor, fabricator or erector – and each has a clear approval step. Understanding the set helps buyers review submissions quickly and avoid delays. The typical sequence is:

1. Design criteria and quotation drawings
2. Approval (general arrangement) drawings
3. Anchor bolt plan and reactions
4. Design calculations (and, where required, sealed submissions)
5. Erection drawings
6. Shop (fabrication) drawings and CNC data
7. 3D model / IFC and as-built records

What each deliverable contains

Anchor bolt plan first

Foundations are usually built by a local contractor while the steel is in fabrication, so the anchor bolt plan and reactions are issued first, typically immediately after approval drawings are signed. Reactions are given unfactored by load type (dead, collateral, live, snow, wind, seismic, crane) so the foundation designer can apply local combinations. Anchor bolt projections, grout thickness and tolerances must be respected; see base plates and anchor bolts and foundations interface.

Calculations, approvals and local requirements

• United States and Canada: building permits typically require drawings and calculations sealed by an engineer licensed in the state or province; Canadian projects also need a letter of assurance or similar from the designer.
• Australia and New Zealand: design certification by a chartered or registered engineer (e.g. CPEng / RPEQ in Queensland) under the National Construction Code or NZ Building Code.
• Europe: design to Eurocodes with National Annexes; CE marking under EN 1090-1 requires a factory production control route to be arranged per project.
• Most markets require that the design criteria – codes, loads, deflection limits, materials – be stated on the general notes of the drawings.

Late changes to openings, cranes, mezzanines or loads after approval drawings affect calculations, anchor bolts and fabrication. Freeze scope at the approval stage wherever possible.

Design certification and what the erection set contains

Many authorities and owners ask the PEB supplier for a formal statement that the building was designed for the specified criteria. In North American practice this is a letter of design certification (or letter of assurance in some Canadian provinces) signed by the supplier's engineer, listing the code edition, risk category, roof live, snow, collateral, wind and seismic parameters, crane and mezzanine loads, and the deflection criteria used. In Australia and New Zealand an equivalent design certificate is issued by the registered engineer, and in Europe the design basis is recorded in the declaration documentation for the steel components. The certificate covers the steel package only; foundations, slab and non-supplied items remain with the engineer of record.

Each issue carries a revision mark and date; superseded sheets should be withdrawn from site so that erection always follows the current revision.

Erection, shop drawings and IFC at WSC

World Steel produces the full deliverable set in-house: approval drawings, anchor bolt plans, calculations, erection and shop drawings, CNC data for cutting and drilling lines, and IFC models for coordination. The IFC model allows clients and consultants to check clashes with services and view the structure in 3D. Learn more in BIM, IFC and shop drawings, the design-and-build process, and WSC's design service.