Title 13 — Planning, Zoning and Development›Chapter X — NONCONFORMING USES, DEVELOPMENTS AND LOTS

§ 13-204. Nonconforming provisions.

Costa Mesa Zoning Code · 2026-06 edition · updated 2026-07-25 · Costa Mesa

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

	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
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
TYPE OF DEVELOPMENT	ALTERATION OF DEVELOPMENT	*REBUILDING AFTER DESTRUCTION*

	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
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
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)

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