California Code, Government Code - GOV § 67600

After the transbay transit terminal has been transferred to the authority, it may thereafter proceed with construction of the regional transit terminal. It may also thereafter enlarge or extend the regional transit terminal if such enlargement or extension is, in its judgment, necessary or convenient for the development of transportation service in the San Francisco Bay area. Such terminal or enlargement or extension thereof shall be constructed in such a manner that it conforms to building codes of the City and County of San Francisco.