Design phases and construction phases rarely run to the same schedule, and construction commonly slips. Since a TN admission is granted for a defined period, plan around what happens if site attendance is still required after that period, rather than assuming the contract and the status will end together.
Check the schedule against the period granted
Ask the client for a realistic construction schedule, including likely delays, and compare it to the period the applicant expects to be granted. Discuss with counsel what extending would involve and what evidence would support it, well before the current period nears its end. Also confirm whether design work can proceed from Canada during gaps in site activity.
Hypothetical example: an engineer responsible for site grading and stormwater structures signs on to a build with a nine-month schedule that everyone privately expects to run past a year. Two dates matter and they are not the same: the period recorded at admission, and the date of the last certified site visit the contract requires. Write both on the schedule and mark the gap between them.
Where the gap is real the options are narrow and each needs lead time, so raise them with counsel while the project is still in its early phases. Confirm as well which deliverables can be produced from Canada, since a design task that does not require presence at the site does not consume the granted period.