When do I actually need stamped drawings?

What a stamped drawing actually is

A "stamp" is the wet seal of a Professional Engineer licensed to practise in the jurisdiction. In Ontario, that means a P.Eng. registered with Professional Engineers Ontario (PEO). The stamp goes on each drawing sheet that contains structural design — it's not a single document, it's per-sheet authentication.

The seal contains: the engineer's name as licensed, the PEO licence number, and the engineer's signature (sometimes embedded in the seal, sometimes adjacent). Digital signatures are accepted as long as the chain-of-custody is documented.

When you need one

You need stamped drawings for a mezzanine or stair project when:

• The work requires a building permit — which it almost always does for a structural mezzanine. See mezzanine permits in Ontario.
• The project is in a building under occupant load — and the new structure is going to carry occupant load itself.
• The project alters the egress system — adding a stair, modifying egress capacity, retrofitting an existing exit stair.
• An insurer or vendor pre-qualification requires it — common for industrial GC pre-qualification programs even when not strictly code-required.
• Internal corporate compliance requires it — many large companies (3PLs, manufacturers) require P.Eng.-stamped designs on any structural addition regardless of permit status.

When you might not

A small handful of cases don't require stamps:

• Free-standing equipment-support stands below permit thresholds, not affecting building structure.
• Minor architectural railings on existing stairs that aren't altering the egress path.
• Repair or replacement of identical components — like-for-like, not changing the design.

These are narrower exceptions than buyers often think. When in doubt, get the stamp.

What's not a stamped drawing

A few things that look like stamped engineering aren't:

• An engineering review letter — a written opinion that something built to the attached drawing meets code. Useful in some retrofit scenarios but not interchangeable with stamped design drawings for new construction.
• A vendor's load-rating sheet — a manufacturer's published capacity for a catalogue product. Doesn't account for your specific application or building.
• An out-of-province engineer's stamp — a stamp from another province's engineering body isn't valid in Ontario unless that engineer is also PEO-registered.
• A drawing prepared by an engineer but not stamped — common from contractors with engineering on staff who didn't seal the document. Permit officers reject these.

How to verify a stamp

Every PEO licence number can be verified at the PEO public licence lookup. Search by name or licence number; you'll see the engineer's status, registration date, and discipline. We list our staff engineers' licence numbers on the team page.

What the stamp covers

The P.Eng.'s stamp is the engineer taking professional responsibility for the structural design contained in the drawing — load calculations, member sizing, connection design, and (where applicable) anchor design and code-compliance demonstration. It does not cover:

• Architectural decisions (placement, finishes, aesthetics).
• Mechanical/electrical equipment installed on or near the structure.
• Construction means and methods — those are the contractor's responsibility.
• Ongoing maintenance — the as-built condition of the structure post-handoff.

How long does it take?

For a typical mezzanine project, the stamped drawing comes 5 – 7 working days after a site measure. Stair retrofits are usually faster (3 – 5 days). Complex projects with anchor design into existing structure can take longer because of the verification step. We don't separate engineering as a line item — it's bundled in the project quote.