The contractor who built the house seems to believe that it's SOP for telephone conduit here in CA.

It's not required unless it's commercial construction but it's definately good practice. So kudos to your builder. Conduit is much better than direct buried for a number of reasons.

-Hal


CALIFORNIA PROPOSITION 65 WARNING: Some comments made by me are known to the State of California to cause irreversible brain damage and serious mental disorders leading to confinement.