A professional seal, often called an engineer's stamp, is the mark a licensed engineer, architect or surveyor places on drawings, calculations and specifications to show that they take professional and legal responsibility for the work shown. Where the law requires it, sheets submitted for permits or construction are not valid without it.
At a glance
| Who applies it | A licensed or registered professional (engineer, architect, surveyor) |
| What it certifies | That the work was prepared by them or under their direct supervision, and they take responsibility for it |
| Where required | Set by the law of each jurisdiction (state, province or country) |
| Shows | Name, licence or registration number, jurisdiction, often signature and date |
| Forms | Embossed seal, rubber stamp, or a digital seal with a certified signature |
What a seal contains
- The professional's name and licence or registration number.
- The jurisdiction and discipline (for example, professional engineer in a given state).
- A signature and date, often across the seal.
- On digital documents, a digital signature that shows whether the file was changed after sealing.
How it is used on projects
The seal belongs to a person, not a firm, and to a jurisdiction. A structural engineer licensed in one state can't seal drawings for a project in another state without being licensed there. Sheets are sealed when issued for permit or construction; preliminary issues often carry "Preliminary, not for construction" instead. Changes after sealing require a new revision and a new seal.
For a BIM coordinator, the seal matters in three ways: it tells you which sheets are the responsible designer's issued design; a model is rarely sealed, so the drawings often govern contractually; and a missing seal on a construction issue is a question to ask before anyone builds.
Variations
- North America: licensing boards in each state or province set sealing rules; many require seals on every sheet.
- UK and much of Europe: there is usually no sealing law for most building work; responsibility follows the appointment and professional registration, and drawings are signed or approved in the title block instead.
- Historic drawings often name the consulting engineer in the title block without a seal.
Common mistakes
- Treating a seal as decoration or as a firm's logo.
- Relying on a sealed sheet that has since been revised without a new seal.
- Copying a seal image into a template so unsealed sheets appear sealed: misleading, and illegal in many places.
- Assuming the model carries the same responsibility as the sealed drawings.
Where to read more
The licensing board or registration body in the project's jurisdiction (for example, a state board of professional engineers); national model laws for engineering practice; and the project contract, which states which documents are the sealed contract documents.