California Code, Government Code - GOV § 66498.5

(a) If a subdivider does not seek the rights conferred by this chapter, the filing of a vesting tentative map shall not be a prerequisite to any approval for any proposed subdivision, permit for construction, or work preparatory to construction.

(b) The rights conferred by a vesting tentative map as provided by this chapter shall last for an initial time period, as provided by ordinance, but shall not be less than one year or more than two years beyond the recording of the final map.  Where several final maps are recorded on various phases of a project covered by a single vesting tentative map, the one-year initial time period shall begin for each phase when the final map for that phase is recorded.

(c) The initial time period shall be automatically extended by any time used by the local agency for processing a complete application for a grading permit or for design or architectural review, if the time used by the local agency to process the application exceeds 30 days from the date that a complete application is filed.  At any time prior to the expiration of the initial time period provided by this section, the subdivider may apply for a one-year extension.  If the extension is denied by an advisory agency, the subdivider may appeal that denial to the legislative body within 15 days.

(d) If the subdivider submits a complete application for a building permit during the periods of time specified in subdivision (c), the rights conferred by this chapter shall continue until the expiration of that permit, or any extension of that permit granted by the local agency.