Granted I don’t know the local rules where this house was built, but every other project I have ever been on, there is an engineered set of plans submitted for plan review from the AHJ, prior to any permits being issued. These plans have a civil drawing showing any easements that may be present. The approved plans become part of the contract documents, which any lenders on the project get a copy of as part of the lending process.
Regardless of any mistakes that make it through plan review the builder has the responsibility to ensure the building meets all local codes. If a 200A feeder is shown with #3 AWG, and somehow makes it past plan review, the builder still has to use the proper wire size for the feeder, and can not blame the inspector for failing him if he does not. “It made it past plan review” is a poor excuse for doing something wrong.
