Title 13 — Planning, Zoning and Development

Chapter X — NONCONFORMING USES, DEVELOPMENTS AND LOTS

Costa Mesa Zoning Code · 2026-06 edition · ingested 2026-07-06 · Costa Mesa

§ 13-201. Purpose.

The purpose of this chapter is to identify the development parameters regarding nonconforming uses, developments and lots. (Ord. No. 97-11, § 2, 5-5-97)

§ 13-202. Definitions.

The following terms and phrases when used in this chapter shall have the meanings ascribed to them in this section, except where context clearly indicates a different meaning:

Conforming use. An existing and legally established use which is permitted in a particular zone by this Zoning Code.

Conforming development. An existing and legally established development which conforms to the development standards required by this Zoning Code.

Nonconforming development. An existing and legally established development which no longer conforms to the development standards required by this Zoning Code.

Nonconforming dwelling unit. An existing and legally established dwelling unit which no longer conforms to the development standards required by this Zoning Code or which is located in a district where it is no longer permitted.

Nonconforming lot. An existing and legally established lot not complying with the minimum area and dimension standards required by this Zoning Code.

Nonconforming mobile home park. An existing and legally established mobile home park which no longer conforms to the development standards or location provisions required by this Zoning Code.

Nonconforming use. An existing and legally established use which is located in a district where it is no longer permitted by this Zoning Code.

Nonconforming use of land or of land with minor structures only. An existing and legally established use which is located in a district where it is no longer permitted by this Zoning Code and where such use involves no individual structure with a replacement cost exceeding $5,000.

(Ord. No. 97-11, § 2, 5-5-97)

§ 13-203. Maintenance and repair.

  • (a) Nothing in this chapter shall prevent the strengthening or restoring to a safe condition any structure or part thereof declared to be unsafe, except as noted in subsection (b) , by order of any official charged with protecting the public safety, nor shall it prevent alterations necessary for compliance with requirements of other governmental agencies.

  • (b) If a nonconforming development or portion of a development containing a nonconforming use becomes physically unsafe or unlawful because of lack of repairs or maintenance and is declared by any duly authorized official to be unsafe or unlawful by reason of physical condition, it shall not thereafter be restored, repaired or rebuilt except in conformity with the regulations of the district in which it is located.

  • (Ord. No. 97-11, § 2, 5-5-97)

§ 13-204. Nonconforming provisions.

The following table identifies the provisions governing nonconforming uses and/or developments:

TABLE 13-204
NONCONFORMING PROVISIONS—USES		 TABLE 13-204
NONCONFORMING PROVISIONS—USES
TYPE OF USE CONTINUANCE OF A USE PERMITTED CHANGE OF USE PERMITTED
Conforming Use in a
Nonconforming Development		 YES—No restrictions on use. YES—Exception: If the development has less parking
than required for the existing conforming use, the
existing use may not be replaced with a use requiring
more parking unless the additional parking required
for the new use is provided. Other uses on the same
site may continue with the existing nonconforming
parking.
Nonconforming Use in a
Conforming or Nonconforming
Structure:
Nonresidential Structures
Residential Structures		 YES—However, when a nonconforming
use is discontinued or abandoned for 6
consecutive months or for 18
nonconsecutive months during any three-
year period (except when government
action impedes access to the premises) or
when it is replaced for any time period by a
conforming use, the development shall not
thereafter be used except in conformity
with the regulations of the district in which
it is located. For purposes of this chapter, a
discontinued use shall not require a
determination of the voluntary or
involuntary nature of the discontinuance or
the intent to resume the nonconforming
use.
YES—However, when a nonconforming
use is discontinued or abandoned for any
period of time, it may not be reestablished.
All subsequent uses in the residential
structure shall conform to this Zoning
Code.		 YES—Any nonconforming use may be changed to
another nonconforming use provided that the
development services director fnds that the proposed
use is equally appropriate or more appropriate to the
district than the existing nonconforming use. In
permitting such a change, the development services
director may require appropriate conditions and
safeguards in accordance with the provisions of this
Zoning Code and/or may require reasonable
alterations to the premises to bring them into greater
conformance with the requirements for the district.
Structural alterations, conforming to the provisions of
this Zoning Code, may be approved by the
development services director provided that it is
determined that the proposed alterations do not
extend the life of the nonconforming use.
YES—However, only to a use conforming to the
provisions of this Zoning Code.
Nonconforming Mobile Home
Parks		 YES—A nonconforming mobile home park
may continue unless and until no one
resides onsite for a continuous period of 6
months.		 YES—However, the conversion is subject to the
procedures for Mobile Home Park Conversions in
Chapter III Planning Applications.
TABLE 13-204
NONCONFORMING PROVISIONS—USES		 TABLE 13-204
NONCONFORMING PROVISIONS—USES
--- --- ---
TYPE OF USE CONTINUANCE OF A USE PERMITTED CHANGE OF USE PERMITTED
Nonconforming Use of Land or
Land with Minor Structures only		 1. Legally established agricultural uses
may continue until the land is developed.
2. If the use is discontinued or abandoned
for any period of time, all subsequent uses
shall conform to this Zoning Code.
3. No nonconforming use shall be enlarged
or increased, nor extended to occupy a
greater area of land than was occupied at
the time it became nonconforming.
4. No nonconforming use shall be moved
in whole or in part to any portion of the lot
other than that occupied by such use at
the time the use became nonconforming.		 YES—However, only to a use conforming to the
provisions of this Zoning Code.
TABLE 13-204
NONCONFORMING PROVISIONS—DEVELOPMENTS		 TABLE 13-204
NONCONFORMING PROVISIONS—DEVELOPMENTS
--- --- ---
TYPE OF DEVELOPMENT ALTERATION OF DEVELOPMENT REBUILDING AFTER DESTRUCTION
TABLE 13-204
NONCONFORMING PROVISIONS—USES		 TABLE 13-204
NONCONFORMING PROVISIONS—USES
All Nonresidential
Developments containing
Nonconforming Uses		 No existing development devoted to a
nonconforming use shall be structurally
altered except in changing the use of the
development to a conforming use. Except
that structural alterations, conforming to the
provisions of this Zoning Code, may be
approved by the development services
director provided that it is determined that
the proposed alterations do not extend the
life of the nonconforming use.
Ordinary maintenance shall be permitted.		 The following provisions shall apply to the reconstruction
of legal nonconforming commercial, industrial and
institutional developments. Any reconstruction allowed
must be started within a period of one year and carried
out diligently to completion. An extension of time to start
the restoration may be granted for good cause by the
development services director.
1. Should a nonconforming commercial, institutional or
industrial development or nonconforming portion of a
commercial, institutional or industrial development be
destroyed to an extent of more than 50 percent of the
market value, it shall not be reconstructed unless such
destruction is unintentional.
In the case of unintentional destruction, the
development may be restored to its original building
intensity (foor area ratio) and use provided that:
a. The rebuilding complies with all other applicable
sections of this Zoning Code and other codes including
but not limited to the following development standards:
building setback, lot coverage, building height, parking,
open space and landscaping.
b. The rebuilding would not increase the development's
nonconformity.
2. Should a nonconforming commercial, institutional or
industrial development or nonconforming portion of a
commercial, institutional or industrial development be
unintentionally destroyed by any means to an extent of
50 percent or less of the market value, the structure may
be restored and the occupancy or use of such structure
or part thereof may be continued or resumed provided
that the restoration is of an equal or lesser degree of
nonconformity.
Nonconforming
Nonresidential Developments
containing Conforming Uses		 Alterations may be made provided that all of
the following criteria are met:
1. The alteration itself complies with all
applicable sections of this Zoning Code and
other codes;
2. In permitting such an alteration, the
development services director may require
appropriate conditions and safeguards in
accordance with the provisions of this
Zoning Code and/or may require reasonable
alterations to the development to bring it into
greater conformance with the standards for
the district; and
3. The development will not be made more
nonconforming.
Nonconforming Use of Land
or Land with Minor Structures
only		 No nonconforming structure shall be erected
or altered in connection with the
nonconforming use of land.
TABLE 13-204
NONCONFORMING PROVISIONS—DEVELOPMENTS		 TABLE 13-204
NONCONFORMING PROVISIONS—DEVELOPMENTS
--- --- ---
TYPE OF DEVELOPMENT ALTERATION OF DEVELOPMENT REBUILDING AFTER DESTRUCTION
Nonconforming Dwelling
Units containing Conforming
Uses		 Alterations may be made to nonconforming
dwelling units provided the following criteria
are met:
1. The zone is residential;
2. The alteration or addition itself complies
with all applicable sections of this Zoning
Code and other codes;
3. The addition does not occupy the only
portion of an area which can be used for
required garages, parking spaces or access
thereto; and
4. The residential development will not be
made more nonconforming.
5. When the existing main building,
excluding architectural features, projects
into required setback areas, minor building
additions may encroach into required
setback areas with approval of a minor
modifcation.		 The following provisions shall apply to the reconstruction
of legal nonconforming dwelling units. Any
reconstruction allowed must be started within a period of
one year and carried out diligently to completion. An
extension of time to start the restoration may be granted
for good cause by the development services director.
1. If the unit(s) in any residential zone is/are destroyed
unintentionally by any means, to any extent, the damage
may be restored and the occupancy continued or
resumed provided that the restoration is of an equal or
lesser degree of nonconformity.
2. See section13-205regarding provisions for
rebuilding after voluntary destruction in multi-family
zones.
3. Should a legally constructed dwelling unit in a
commercial or industrial zone be destroyed by any
means to an extent of more than 50 percent of the
market value, it shall not be reconstructed.
4. Should a legally constructed dwelling unit in a
commercial or industrial zone be unintentionally
destroyed by any means to an extent of 50 percent or
less of the market value, the structure may be restored
and the occupancy or use of such structure or part
thereof may be continued or resumed provided that the
restoration is of an equal or lesser degree of
nonconformity.
TABLE 13-204
NONCONFORMING PROVISIONS—USES		 TABLE 13-204
NONCONFORMING PROVISIONS—USES
Nonconforming or
Conforming Dwelling Units
containing Nonconforming
Uses		 1. No existing development devoted to a
nonconforming use shall be structurally
altered except in changing the use of the
development to a conforming use. Except
that structural alterations, conforming to the
provisions of this Zoning Code, may be
approved by the development services
director provided that it is determined that
the proposed alterations do not extend the
life of the nonconforming use. Ordinary
maintenance shall be permitted.
2. In nonconforming mobile home parks,
existing mobile homes may be replaced by
other mobile homes provided that the total
number of units within the mobile home park
is not increased and the mobile home park
will not be made more nonconforming in
respect to this Zoning Code.
Nonconforming Mobile Home
Parks

(Ord. No. 97-11, § 2, 5-5-97; Ord. No. 98-5, § 28, 3-2-98)

§ 13-205. Provisions for multi-family zones for rebuilding after voluntary destruction.

  • (a) If units in the R2-MD, R2-HD, R3 or PDR zones are voluntarily demolished, an equal or lesser number of units may be rebuilt so long as the development complies with all other applicable sections of this Zoning Code and other codes. This includes but is not limited to the following development standards: building setback, lot coverage, building height, parking, open space and landscaping. Furthermore, the allowable density or number of units to be redeveloped shall be limited to the general plan rebuilding incentive for the current land use designation. The resulting number of units shall not exceed the existing number of legal nonconforming units nor be more than the number of units that would have been allowed on March 15, 1992. The rebuilding shall not increase the development's nonconformity.

  • (b) Consideration may be given through the master plan process, to allow rebuilding of existing multiple-family residential projects that do not fully meet all the other applicable sections of this Zoning Code and other code standards. Consideration shall be given to the provision of tandem parking for units requiring more than one dedicated parking space and for cantilevered second story living areas over drive or yard areas. Through the master plan process, the rebuilding project must demonstrate why strict compliance with each of the current standards is either infeasible or unnecessary. In exchange for any deviation from current standards, the project must provide additional amenities such as those listed below:

    • (1) Provision of garages instead of carports for greater security.

    • (2) Useable open space with amenities.

    • (3) Flower beds and adequate lawns of sufficient area to create a useable recreation area.

    • (4) Individual vegetable garden areas screened by hedges.

    • (5) Masonry planters, potted flowers and shrubs on decks and balcony flower boxes.

    • (6) Trellises with vines.

    • (7) Minimum size trees based on box size rather than gallons such that 30% or more of the trees are a minimum twenty-four-inch box size.

    • (8) CC&Rs to ensure landscape maintenance.

    • (9) On-site manager for projects of 15 units or less.

    • (10) Awnings, especially along the front for color and product definition, and a better facade.

    • (11) Stamped concrete or decorative at entrances and critical driveway intersections.

    • (12) Meandering rather than straight sidewalks.

    • (13) Terraced elevations at all sides to reduce scale and massing.

    • (14) Upgraded windows and doors for noise reduction.

    • (15) Covered/screened dumpsters for projects of four units or less.

    • (16) Concrete slab where the trash truck would stop to compact trash to prevent damage, or contract for roll-off service so that the trash truck does not come on-site.

    • (17) Orientation of units away from the street toward interior courtyards.

    • (18) Adequate lighting for security (beyond parking and driveway lighting required by code).

    • (19) Gates and intercom system for security.

  • (20) Other amenities that enhance the project and the overall neighborhood.

  • (c) In reviewing the master plan, the planning commission shall decide if the degree of deviation is warranted, if the proposed amenities are sufficient to offset the deviation, and if the maximum allowable density shall be reduced due to the deviation.

  • (d) The master plan shall be processed as shown in Chapter III, Planning Applications.

  • (e) Findings. The findings necessary to grant the master plan are:

    • (1) Full compliance with current development standards would make rebuilding infeasible;

    • (2) The proposed rebuilding is substantially compatible with surrounding developments and would not be materially detrimental to other properties in the area;

    • (3) The proposed rebuilding is less nonconforming than the existing development; and

    • (4) The proposed rebuilding provides additional amenities that ensure a high quality development.

(Ord. No. 97-11, § 2, 5-5-97; Ord. No. 98-5, § 29, 3-2-98; Ord. No. 05-3, § 1h., 2-7-05)

§ 13-206. Nonconforming fences and walls.

Nonconforming fences or walls may remain unless destroyed, damaged or altered (by any means or cause) to the extent of more than 50% of its value. When the destruction, damage or alteration exceeds 50% of its value then the reconstruction shall conform to the Zoning Code.

(Ord. No. 97-11, § 2, 5-5-97)

§ 13-207. Nonconforming lots.

  • (a) Uses permitted in the zone shall be permitted on nonconforming lots, subject to all other property development standards of the zone.

  • (b) When two or more contiguous nonconforming lots or portions of lots are held under common ownership, they shall be deemed merged when and as provided for in the Subdivision Map Act (State Government Code Sections 66410 to 66499.58 ).

  • (Ord. No. 97-11, § 2, 5-5-97)

§ 13-207.1. Group homes.

If any lawfully existing group home is in violation of section 13-30 and (i) it would be an economic hardship to bring the use into compliance immediately, or (ii) a vested right exists to continue the use, the development services director may, upon request of the owner or at the director's own initiative, establish a reasonable amortization period by the end of which the use must be in compliance.

(Ord. No. 00-5, § 1(f), 3-20-00)