Costa Mesa · Building on your lot

Building on your lot in Costa Mesa

Costa Mesa sets fence limits on corner lots and near intersections and limits home businesses to one room inside the home. It also has a section on accessory buildings and structures.

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Key points

Corner fences: On corner lots, fences over 3½ feet must be 5 feet from the street side line; in a visibility triangle, 2½ feet.
Home businesses: A home business needs a permit and business license, is limited to one room inside the home, and only permanent residents may work there.
Accessory structures: Costa Mesa regulates accessory buildings and structures in Section 13-33 of its code.

Each rule below is marked Costa Mesa code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.

Fences and walls

Costa Mesa code What Costa Mesa's code adds
Corner visibility	Corner lots: walls or fences over 3.5 feet must be set back 5 feet from the street side property line. Applies: Inside a visibility triangle, fences, walls and landscaping may be no more than 2.5 feet tall. § 13-75 · code text On corner lots, wall and fences in excess of three and a half feet in height shall be set back five feet from the street side property line.

Running a business from home

Costa Mesa code A home business needs a permit and business license, is limited to one room inside the home, and only permanent residents may work there.

All 10 Costa Mesa rules on running a business from home, with the code text →

Solar panels and EV chargers

Costa Mesa code What Costa Mesa's code adds
EV charger permit	Approved administratively, with all permits issued, once the application meets the checklist, applicable laws and health and safety standards. Applies: Applies to permit applications that meet the city's adopted checklist. § 5-148 · code text Upon confirmation from the building official that the permit application and supporting documents meet the requirements of the city's adopted checklist, and is consistent with all applicable laws and health and safety standards, the building official shall, consistent with Government Code section 65850.7, administratively approve the application and issue all necessary permits. You may submit permit applications and supporting documents electronically. § 5-148 · code text Consistent with Government Code section 65850.7, the building official shall allow for electronic submittal of permit applications and associated supporting documentation.
Solar permit process	Administrative, nondiscretionary review; a permit is issued if the application meets the approved checklist and standard plan. Applies: Applies to small residential rooftop solar systems. § 5-143 · code text For an application for a small residential rooftop solar energy system that meets the requirements of the approved checklist and standard plan, the building department shall issue a building permit or other non-discretionary permit within three business days. Only 1 inspection, scheduled within 2 business days of a request. Applies: Applies to small residential rooftop solar systems eligible for expedited review. § 5-143 · code text Only one inspection shall be required and performed by the building department for small residential rooftop solar energy systems eligible for expedited review.
Review time	The permit is issued within 3 business days. Applies: Small residential rooftop solar, when the application meets the approved checklist and standard plan. § 5-143 · code text For an application for a small residential rooftop solar energy system that meets the requirements of the approved checklist and standard plan, the building department shall issue a building permit or other non-discretionary permit within three business days.

Swimming pools

Costa Mesa code What Costa Mesa's code adds
Maintenance and empty pools	The pool must be drained immediately and may not be refilled until the fence complies. Applies: Applies when the pool's enclosure fence does not meet the code. § 5-68 · code text Any swimming pool enclosed by a fence which fence does not meet the requirements of this chapter shall be drained immediately and shall not be refilled until such time as the enclosure fence is brought into compliance with all of the provisions of this chapter.

Pets, chickens and bees

Costa Mesa code What Costa Mesa's code adds
Bees	Yes; at most 2 production hives, plus temporary expansion hives as needed to manage swarming. Applies: Applies to residential properties with a residential beekeeping permit. § 3-18.4 · code text A maximum of two production hives are permitted, with additional temporary expansion hives allowed as needed to manage swarming. At least 15 feet from lot lines and 25 feet from neighboring homes; otherwise, a 6-foot solid barrier is required. Applies: Applies to beehives; the code says hives should meet these distances. § 3-18.4 · code text Beehives should be located at least 15 feet from any property line and 25 feet from neighboring residential buildings unless measured as described in subsection (c)(1)(b) below are met.
Permit	A residential beekeeping permit from the police department's animal services unit is required. Applies: Applies to all domesticated hives. § 3-18.4 · code text A residential beekeeping permit is required for all domesticated hives.

Building in a flood zone

Costa Mesa code A permit is required for all proposed development. No permanent buildings except for flood drainage, utilities and roads; no encroachments that raise flood levels or block flood flows.

All 5 Costa Mesa rules on building in a flood zone, with the code text →

Grading and erosion control

Costa Mesa code What Costa Mesa's code adds
Grading without a permit	Fill under 1 foot deep on slopes flatter than 5:1, at most 20 cubic yards per lot, not blocking drainage. Applies: Applies to fill placed on natural grade. A compaction report must still go to the Building Official. § 5-1.4.1 · code text A fill less than one (1) foot in depth which: (1) is placed on a natural grade with a slope less steep than five horizontal to one vertical (5:1); (2) does not exceed twenty (20) cubic yards on any one lot; and (3) does not obstruct a drainage course. Planter fill under 3 feet deep, at most 20 cubic yards on any one lot, not blocking a drainage course. Applies: Applies to fill for a landscape planter. § 5-1.4.1 · code text A fill less than three (3) feet in depth for a landscape planter, which does not exceed twenty (20) cubic yards on any one lot and does not obstruct a drainage course.

Noise and construction hours

Costa Mesa code 7:00 a.m. to 7:00 p.m. 9:00 a.m. to 6:00 p.m.

All 6 Costa Mesa rules on noise and construction hours, with the code text →

Family child care homes

CA state law California law
Zoning	A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning Health & Safety Code § 1597.45(a)
Business license or fee	A city or county may not charge a business license, fee or tax to run a family child care home Health & Safety Code § 1597.45(b)
Local rules	Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone Health & Safety Code § 1597.45(e)
Small home	Up to eight children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(c)
Large home	7 to 14 children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(b)

Affordable units in new housing (inclusionary)

Costa Mesa code At least 55 years or as the agreement states; may end after 55 years only if redeveloped as non-residential. The fee follows a schedule adopted by the city council.

All 6 Costa Mesa rules on affordable units in new housing (inclusionary), with the code text →

Group homes and residential care

Costa Mesa code All garage and driveway spaces for the dwelling unit must be available for parking vehicles at all times. A conditional use permit is required.

All 9 Costa Mesa rules on group homes and residential care, with the code text →

Home alarm permits and false alarms

Costa Mesa code An audible alarm must shut off within 15 minutes after it starts, by automatic cutoff or manual operation. A service charge applies to each false alarm from the third police response or second fire response in 12 months.

All 4 Costa Mesa rules on home alarm permits and false alarms, with the code text →

Historic homes

Costa Mesa code What Costa Mesa's code adds
Changing a historic home	A certificate of appropriateness is required to restore, rehabilitate, alter, develop, construct, demolish, remove or change a cultural resource's appearance. Applies: Applies to a cultural resource on the local Register of Historic Places. § 13-200.10 · code text No person, owner, or other entity shall restore, rehabilitate, alter, develop, construct, demolish, remove or change the appearance of any cultural resource on the local Register of Historic Places without first having applied for and been granted a certificate of appropriateness to do so by the planning commission (or other commission/committee designated by the city council).
Mills Act tax incentive	The city council may adopt a preservation incentives program that includes Mills Act contracts. § 13-200.11 · code text This program may include but is not limited to: (a) Mills Act contracts;

Other Costa Mesa rules on this

Costa Mesa's code also has these chapters. We have not summarized their values on this page yet; read them in the library.

Accessory buildings and structures (§ 13-33)
Urban lot split (SB 9) (§ 13-265.5)
Two-unit housing development (SB 9) (§ 13-36)

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How tall can a fence be in Costa Mesa?

On corner lots, fences over 3½ feet must be 5 feet from the street side line; in a visibility triangle, 2½ feet.

How big can a shed or accessory building be in Costa Mesa?

Costa Mesa regulates accessory buildings and structures in Section 13-33 of its code. Costa Mesa also has a related rule: Accessory buildings and structures (§ 13-33).

Do I need a permit for solar panels or an EV charger in Costa Mesa?

Costa Mesa's code: Administrative, nondiscretionary review; a permit is issued if the application meets the approved checklist and standard plan. (Applies to small residential rooftop solar systems.) (§ 5-143); Approved administratively, with all permits issued, once the application meets the checklist, applicable laws and health and safety standards. (Applies to permit applications that meet the city's adopted checklist.) (§ 5-148).

Can I keep chickens or bees at my home in Costa Mesa?

Costa Mesa's code: Yes; at most 2 production hives, plus temporary expansion hives as needed to manage swarming. (Applies to residential properties with a residential beekeeping permit.) (§ 3-18.4); At least 15 feet from lot lines and 25 feet from neighboring homes; otherwise, a 6-foot solid barrier is required. (Applies to beehives; the code says hives should meet these distances.) (§ 3-18.4).

What are the grading rules in Costa Mesa?

Costa Mesa's code: Fill under 1 foot deep on slopes flatter than 5:1, at most 20 cubic yards per lot, not blocking drainage. (Applies to fill placed on natural grade. A compaction report must still go to the Building Official.) (§ 5-1.4.1); Planter fill under 3 feet deep, at most 20 cubic yards on any one lot, not blocking a drainage course. (Applies to fill for a landscape planter.) (§ 5-1.4.1).

Can I run a family child care home in Costa Mesa?

California law sets this for every city, including Costa Mesa: Zoning: A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning (Health & Safety Code § 1597.45(a)); Business license or fee: A city or county may not charge a business license, fee or tax to run a family child care home (Health & Safety Code § 1597.45(b)); Local rules: Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone (Health & Safety Code § 1597.45(e)); Small home: Up to eight children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(c)); Large home: 7 to 14 children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(b)).

What rules apply to a historic home in Costa Mesa?

Costa Mesa's code: A certificate of appropriateness is required to restore, rehabilitate, alter, develop, construct, demolish, remove or change a cultural resource's appearance. (Applies to a cultural resource on the local Register of Historic Places.) (§ 13-200.10); The city council may adopt a preservation incentives program that includes Mills Act contracts. (§ 13-200.11).

General information, not legal advice.

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