Diamond Bar, Cal., Code of Ordinances ch. 21.24 § 21.24.030

A condominium conversion is the conversion of real property to a common interest development as defined by California Civil Code § 1351. A conversion shall require the approval of a tentative map, and parcel or final map, except where a parcel map, or tentative and final map are waived in compliance with map act § 66428(b) or 66428.1, for the conversion of a mobile home park. If a parcel map is waived, a tentative map shall still be required.
A tentative map for a condominium conversion shall be filed in the same form, have the same contents and accompanying data and reports and shall be processed, approved or disapproved in the same manner as set forth in chapter 21.20 (Tentative Map Filing and Processing), with the following exceptions: (1)
Application contents. Condominium conversion applications shall include the same information and materials as tentative map applications, except for conversions of residential projects, which shall also include the following information and materials:
a. Tentative map. The tentative map for a condominium, community apartment project, or the conversion of five or more existing dwelling units to a stock cooperative need not show the buildings or the manner in which the airspace above the property shown on the map are to be divided. However, the applicant shall provide an illustration of how division will occur to enable verification of the accuracy of the legal descriptions on deeds for the transfer of ownership of the units.
b. Public notice materials. Business size envelopes will be sent to each tenant of the property being converted, with first class postage affixed to each envelope.
c. Verification of stock cooperative vote. If the development being converted to a condominium is a stock cooperative, the application shall also include verification of the vote required by map act section 66452.10.
d. Relocation assistance program. A program proposed by the applicant that will assist tenants displaced through the conversion in relocating to equivalent or better housing, in compliance with the general plan. This program shall, at a minimum, comply with the provisions of the map act section 66452.8.
e. Vacancy rate assessment. An assessment of the vacancy rate in multifamily housing within the city.
f. Mobile home park conversion impact report. If the development being converted to a condominium is a mobile home park, the application shall also include the report required by map act 66427.4.
(2) Staff report. The staff report on the tentative map for the condominium conversion ( section 21.20.040 ) shall be provided the subdivider and each tenant of the subject property at least three days before any hearing or action on the tentative map by the commission or council.
(3) Public notice. The following notice shall be provided in addition to that required by chapter 22.72 (Public Hearings) of the development code:
a. Tenant notice. The subdivider shall give notice to all existing or prospective tenants as set forth in map act sections 66452.8 and 66452.9, and shall provide the department satisfactory proof that the notice was given; and
b. Public hearing notice. Notice of the public hearing(s) on the tentative map shall be provided to all tenants of the subject property, as required by map act section 66451.3.
(4) Approval of conversion, required findings.
a. Time limit, stock cooperatives. The approval or disapproval of the conversion of an existing building to a stock cooperative shall occur within 120 days of the application being found complete in compliance with section 22.44.050 (Initial application review) of the development code. The 120-day time limit may be extended by mutual consent of the subdivider and the city.
b. Conversion findings, residential projects. Approval of a tentative or final map for a subdivision to be created from the conversion of residential real property into a condominium project, community apartment project or stock cooperative shall not be granted unless the findings set forth in map act section 66427.1 are first made.
c. Limitation on conversions. In compliance with the general plan, no condominium conversion shall be approved while the vacancy rate within the city for multifamily housing is less than four percent.
(5) Completion of conversion. The filing, approval and recordation of a parcel map or final map in compliance with chapter 21.22 (Parcel Maps and Final Maps) shall be required to complete the subdivision process, except where a parcel map, or tentative and final map are waived for the conversion of a mobile home park in compliance with map act section 66428(b) or 66428.1. If a parcel map is waived, a tentative map shall still be required.