The structural detailed design

The measure

Detailed enough for the contractor to work from without asking.

That is not a slogan: the legislation puts it the same way — it has to contain every direct piece of information and instruction that is necessary and sufficient for construction and for producing the shop drawings. The content of the detailed design.

What it contains

• plans and sections at construction detail,
• member layouts and schedules,
• connection drawings — where the quality of the structure is decided,
• reinforcement and erection drawings,
• material grades and execution requirements,
• for a thin-walled structure, the restraint, screw pattern and anchorage marked.

What we stress particularly on the drawings

In thin-walled steel the quality of the structure depends not on the size of the members but on the details. So the drawings have to mark:

• the type, spacing and fixing of the restraint members, Restraint,
• the type of lining and its screw pattern, where the bracing comes from it, Sheathing diaphragm,
• the hold-downs at the ends of the shear walls, Hold-down anchorage.

If these are not on the drawings, the design assumption cannot be verified — and the contractor will build a different structure in good faith.

Why it pays even when not mandatory

Producing a detailed design is not mandatory in every case. Its value is large regardless: comparable tenders, fewer variations, evidence in a dispute — and for a prefabricated structure the shop drawings cannot responsibly be produced without it.

The precondition for shop drawings

If the detailed design is incomplete, the shop-drawing designer is forced to make decisions they are not authorised to make. Input data for shop design.

The point

The detailed design is not a “prettier permit design”. The building is built from it and manufacture starts from it — so the details here are not decoration.