An engineer foundaiton sign off is now required if you live in the Plano area.
Several years ago most Texas cities, including Plano, moved the responsibility for job site inspection out of the city inspector’s office.
To close out a permit, the city requires a Registered Professional Engineer’s seal on a letter attesting that the foundation has been repaired in accordance with the permitted repair plan.
It is possible to inspect a drilled concrete pier to verify steel cage and pier depth prior to pouring concrete. The introduction of superior pier systems, notably pressed concrete pilings and pressed steel pilings, eliminated any possibility of in-process inspection short of watching the whole installation process.