(a) Preliminary Plan. The length of approval of the preliminary plan for a Planned Unit Development shall be 18 months from the date of Council action. An extension may be applied for in writing by the applicant prior to the expiration date, and extensions may be granted by Council twice, each for a period of one year.
(b) Final Plan. The length of approval of a final plan for a Planned Unit Development shall be two years from the date of Council action. An extension may be applied for in writing by the applicant prior to the expiration date, and extensions may be granted by Council twice, each for a period of one year. Where a Planned Unit Development is being developed in phases, the initiation of each new development phase shall automatically extend the approval for two years from the date of issuance of a building permit.