R1 Single-Family Residential District. This district is intended to promote the development of single-family detached units located on lots with a minimum lot size of 6,000 square feet, and a maximum density of 7.26 dwelling units per gross acre.

R2-MD Multiple-Family Residential District, Medium Density. This district is intended to promote the development of multi-family rental as well as ownership properties on lots with a minimum size of 12,000 square feet. The maximum density allowed is 3,630 square feet per dwelling unit, which equals 12 dwelling units per gross acre. Legal lots existing as of March 16, 1992 with a minimum lot area of 6,000 square feet up to 7,260 square feet are allowed two dwelling units.

R2-HD Multiple-Family Residential District, High Density. This district is intended to promote the development of multi-family rental as well as ownership dwelling units on lots with a minimum size of 12,000 square feet. The maximum density allowed is 3,000 square feet per dwelling unit, which equals 14.52 dwelling units per gross acre.

R3 Multiple-Family Residential District. Like the R2-MD and R2-HD districts, this district is intended to promote the development of multi-family rental as well as ownership dwelling units. The required minimum lot size is 12,000 square feet. The maximum density allowed is 2,178 square feet per dwelling unit, which equals 20 dwelling units per gross acre.

AP Administrative and Professional District. This district is intended to establish areas within which public administrative, professional and business offices may be located. It is the further purpose of this district to limit the intensity of use within the district to be compatible with the types of activities generally associated with office developments.

CL Commercial Limited District. This district is intended for unique areas of land which, due to the proximity of residential development or the potential for traffic circulation hazards, require special precautions to be taken to assure appropriate development. The district is also intended for industrial areas where commercial uses must be considered according to their compatibility with existing or permitted industrial uses.

C1 Local Business District. This district is intended to meet the local business needs of the community by providing a wide range of goods and services in a variety of locations throughout the city. The permitted and conditional uses as well as development standards are aimed toward reducing impacts on surrounding properties especially in those areas where residential uses are in the vicinity.

C2 General Business District. This district is intended to provide for those uses which offer a wide range of goods and services which are generally less compatible with more sensitive land uses of a residential or institutional nature.

C1-S Shopping Center District. This district is intended for large commercial lots constructed as a unified and integrated development. It is the further purpose to provide a wide range of goods and services on a community and regional scale.

TC Town Center District. This district is intended to allow intensely developed mixed commercial and residential uses within a very limited geographical area bounded by Sunflower Avenue to the north, 1-405 to the south, Bristol Street to the west, and Avenue of the Arts to the east. Developments within this designation can range from one- and two-story office and retail buildings to mid- and high-rise buildings.

P Off-Street Parking District. This district is intended to allow parking lots, and buildings incidental to the operation of the parking lot.

I & R Institutional and Recreational District. This district is intended to allow land uses which provide recreation, open space, health and public service uses. Development in this designation may occur on either public or private property.

I & R-S Institutional and Recreational School District. This district is intended to allow public and private educational facilities on either public or private property.

MG General Industrial. This district is intended for a variety of industrial areas which contain a wide range of light and general industrial activities. Development standards and the approval of conditional uses shall be aimed toward eliminating possible hazards to adjoining properties, especially in those areas where residential uses are in the vicinity.

MP Industrial Park. This district is intended for large, concentrated industrial areas where the aim of development is to create a spacious environment in a park-like setting.

PDR-LD Planned Development Residential—Low Density (up to 8 dwelling units per acre); PDR-MD Planned Development Residential—Medium Density (up to 12 dwelling units per acre); PDR-HD Planned Development Residential—High Density (up to 20 dwelling units per acre or higher pursuant to an adopted specific plan); PDR-NCM Planned Development Residential—North Costa Mesa (25 to 35 dwelling units per acre). These districts are intended to provide for excellence in the design of residential projects. Within the low-density zone typical designs include small-lot, single-family detached residential developments including clustered development, zero lot line development and conventional development.

Within the medium density, high density, and north Costa Mesa zones, site design could include single-and multiple-family residential developments containing any type or mixture of housing units, either attached or detached, including but not limited to clustered development, townhouses, patio houses, detached houses, duplexes, garden apartments, high rise apartments or common interest developments. Complementary nonresidential uses could also be included in the planned development.

PDC Planned Development Commercial. This district is intended for retail shops, offices and service establishments, including but not limited to, hotels, restaurants, theaters, museums, financial institutions, and health clubs. These uses are intended to serve adjacent residential areas, as well as the entire community and region. Complementary residential uses could also be included in the planned development.

PDI Planned Development Industrial. This district is intended for large, concentrated industrial areas where the aim of development is to create a spacious environment in a park-like setting.

MU Mixed-Use Overlay. This district may overlay the R2-MD, R2-HD, R3, CL, C1, C2, MG, PDR-HD, PDR-MD, or I&R districts, and it is intended to allow development of residential and nonresidential uses as mixed, integrated projects. This overlay district shall only be applied to the zoning map in conjunction with the adoption of an urban plan for the designated area. The urban plan is a regulating plan that shall define the unique characteristics of the overlay area, include a matrix of permitted, conditionally permitted, and prohibited uses and provide development standards. The provisions of the mixed-use overlay shall be activated by adoption of a master plan.

Institutional and Recreational Multi-Use District. This district is intended to allow the integration of a variety of land uses and intensities. This zoning district category includes uses which are low to moderate in density and intensity and urban in character. The multi-use center designation is applicable only to the Fairview Development Center property at 2501 Harbor Boulevard.

When boundaries of zones are approximately following street, alley or lot lines, such lines shall be construed as the boundaries.

In the case of undivided properties, or property not yet subdivided, and a zone boundary divides the lot, the location of the zone boundary, unless indicated by dimensions, shall be determined by the use of the scale appearing on the zoning map.