(a) The time limits for commencement of construction under a permit granted under the California Coastal Zone Conservation Act of 1972 shall be determined from the regulations of the California Coastal Zone Conservation Commission in effect on December 31, 1976 or by any specific actions taken pursuant to the California Coastal Zone Conservation Act of 1972, if not expressly stated in the terms and conditions of the permit.

(b) Prior to the time that commencement of construction under a permit granted by either the regional commission or the commission must occur under the terms of subsection (a) the applicant may, upon payment of a $50 fee (or a $25 fee in the case of extension of permit for single-family residences) apply to the executive director of the commission for an extension of time not to exceed an additional one year period. The application shall be accompanied by evidence of a valid, unexpired permit, acknowledged pursuant to the requirements in effect at the time the permit was issued, and of the applicant's continued legal interest in the property involved in the permit. The application shall be processed in accordance with the procedures of Section 13169.