The wall is open. The post shown on the drawing is not where the old framing says it should be. This is not the moment for a confident pencil alteration by whoever is nearest the sheet.
Record the difference clearly
Photograph the whole area and provide measured dimensions, member sizes, and visible service routes. Identify which drawing and revision you are comparing. A close-up without context can generate another round of questions instead of an answer.
Keep the affected area accessible and follow the professional's direction about temporary conditions. Do not remove additional supports to make the original sketch easier to understand.
Ask for one coordinated instruction
PEO explains who may offer engineering services to the public. The responsible designer should address changes to their design. Ask whether revised permit drawings, a site instruction, further investigation, or another review is needed.
Mississauga's inspection guidance distinguishes stages that must be completed and accepted before later work. Check the process for the actual municipality rather than assuming an email to one party informs everyone.
Close the loop before closing the wall
- Identify the revised drawing or written instruction used on site.
- Confirm any cost and finish changes before proceeding.
- Arrange the required inspection or field review.
- Keep the final documents with the project record.
The useful outcome is not a drawing that was magically right about every concealed condition. It is a construction process that responds accurately when the house reveals something new.