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Local jurisdiction · San Mateo County

Half Moon Bay Zoning, Planning & Building Codes

What you can build in Half Moon Bay depends on its local zoning and planning code, layered on the California Building Standards Code. Ask GoCodebook about any Half Moon Bay address.

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Key points

Zoning districts & allowed uses Setbacks & height limits FAR, lot coverage & density Building permits Remodels & change of use ADUs & JADUs Parking requirements Planning & design review
Last reviewed: July 25, 2026 · AI-generated overview · General information, not legal advice · details

Compiled with AI research tools from official sources. Verify with the jurisdiction.

Overview

Half Moon Bay regulates land use through its coastal-informed zoning code, with most projects also subject to the Local Coastal Program and coastal permitting. The city maps parcels into residential, commercial, industrial, public, agricultural, open space, reserve, PUD, and mobile home districts, with coastal resource and hillside standards layered on top where applicable. Development standards (setbacks, height, FAR, site coverage, and parking) are largely district-based, with targeted citywide rules for design, landscaping, fences, noise, and storage. Accessory dwelling units (ADUs) are broadly allowed—often ministerially—with coastal-process nuances.

If you are building in Half Moon Bay, assume you are in the Coastal Zone: most new development needs a coastal development permit under Chapter 18.20 before a building permit is issued (§ 18.20.025; § 18.20.015).

How Half Moon Bay’s code is organized

  • Code title and maps
    • The zoning ordinance is Title 18 Zoning. The city’s official zoning districts are established at § 18.01.015, and district boundaries/map rules and map amendments are at § 18.01.030 (how to read a boundary) and § 18.01.035 (how changes are recorded).
  • Chapter structure (where the rules live)
    • Residential standards: Chapter 18.06 (development standards, exceptions, and permit/design review) including the core numeric tables in § 18.06.030 and related specifics in § 18.06.040, exceptions in § 18.06.050, and permit/design review in § 18.06.080.
    • Downtown/Main Street commercial and Commercial-Residential: Chapter 18.07 (purpose in § 18.07.010; permitted uses and supplemental use rules in § 18.07.020–.025; development standards for C‑R and C‑D in § 18.07.035–.040; exceptions in § 18.07.045; permits/design review in § 18.07.060).
    • General/Visitor-Serving commercial: Chapter 18.08 (permitted uses and use rules § 18.08.020–.025; general and district standards § 18.08.030–.040; exceptions § 18.08.045; permits/design review § 18.08.060).
    • Public/quasi-public: Chapter 18.09; Industrial: Chapter 18.10; Reserve districts (UR/OSR): Chapter 18.11; Open Space (OS‑A/OS‑P/OS‑C): Chapter 18.12; Agriculture (A‑1/A‑2): Chapters 18.13–18.14; PUD and PUD‑X: Chapters 18.15–18.16; Mobile Home Park: Chapter 18.17; Use permits: Chapter 18.22; Coastal development permits and process: Chapter 18.20; Upland slopes standards: Chapter 18.37; Coastal resource mapping: Chapter 18.38 (§ 18.06.080, chapter index).
  • Navigating uses vs. standards
    • Use allowances are tabled by district (e.g., Tables 18.07.020A–E; 18.08.020A–E), with extra, district- or area-specific use regulations collected in the “Use regulations” sections (§ 18.07.025, § 18.08.025).
    • The numeric development standards you’ll need (setbacks, height, FAR/coverage, density) are in each family’s standards sections (e.g., § 18.06.030 for R‑1/R‑2/R‑3; § 18.08.040 for C‑G) and in the district-specific standards for C‑D/C‑R (§ 18.07.035–.040).

Zoning district families

Half Moon Bay’s official districts are (§ 18.01.015):

  • Residential: R‑1 (single-family), R‑2 (two-family), R‑3 (multi-family).
  • Commercial: C‑D (Commercial–Downtown), C‑R (Commercial–Residential), C‑G (Commercial–General), C‑VS (Commercial–Visitor Serving).
  • Employment/Institutional: IND (Industrial), PS (Public Service).
  • Resource/Reserve: OS‑A, OS‑P, OS‑C (Open Space), U‑R (Urban Reserve), OS‑R (Open Space Reserve).
  • Agriculture: A‑1 (Exclusive Floriculture), A‑2 (Agriculture and Agriculture Reserve).
  • Planned/Mobile: PUD (Planned Unit Development), PUD‑X (Dykstra Ranch PUD), MHP (Mobile Home Park).

Highlights unique to Half Moon Bay:

  • Downtown Main Street “Heritage Main Street” ground-floor rules: the first 50 ft of ground-floor depth on Main Street between Pilarcitos Creek and Correas Street is curated for active uses. For example, business/professional offices are prohibited there; some artisan/maker uses must be ancillary to retail; and certain repairs must be “active ground-floor dependent” (§ 18.07.025, including A‑19, A‑20, A‑21(a)).
  • Visitor-serving nuances: in C‑VS, some uses are limited to visitor-serving functions (e.g., ATMs incidental; labs limited to coastal research; food/beverage sales ancillary to recreation) (§ 18.08.025).
  • Game centers and entertainment: separation, hours-of-use constraints, and onsite management standards apply in commercial districts; bowling alleys and some indoor facilities are limited by district (§ 18.07.025(A‑11); § 18.08.025(A‑11)).

See Half Moon Bay Zoning and Half Moon Bay Land Use for related maps/policies.

Citywide development standards

Below are commonly referenced, citywide baseline rules. Always confirm the exact district standard where you’re building.

  • Residential districts (R‑1/R‑2/R‑3)

    • The R‑1 district sets a typical 20 ft front setback, 5 ft side setback (with a combined side yard of 20% of lot width), 20 ft rear setback, 28 ft max multi‑story height, 35% multi‑story site coverage (50% single‑story), and 0.5 FAR; two garage spaces are required per unit (§ 18.06.030, Table B).
    • R‑2 and R‑3 keep similar basic setbacks (front 20 ft, sides 5 ft, rear 20 ft). Max multi‑story height is 28 ft in R‑2 and 40 ft in R‑3. Multi‑story site coverage is 35% (R‑2) and 45% (R‑3). R‑2 has a 0.5 FAR; R‑3 has no FAR cap but open space is required (§ 18.06.030, Table C).
    • Multifamily open space: provide usable open space equal to 15% of unit floor area (with minimum sizes for private/common open space) (§ 18.06.040(A)).
    • Residential parking geometry: standard stall 9'×19', parallel 10'×22'; aisle widths vary by angle (e.g., 25 ft two‑way at 90°). Guest parking required for duplex/triplex and multifamily per § 18.06.040(D).

  • Commercial districts (selected citywide items + C‑G specifics)

    • Citywide commercial development rules include parking plan submittal for new/intensified uses, landscaping in and around parking (e.g., interior islands min 2 ft wide; 1 tree per 6 spaces), fencing and screening, refuse areas, and exterior noise limits (e.g., 60 dBA daytime hourly limit at R/OS interfaces) (§ 18.08.030(D)–(J)).
    • C‑G standards: minimum lot 10,000 sf and 100 ft width; setbacks 25 ft front and 10 ft side/rear; landscape at least 10% of site; max height 36 ft/3 stories; and residential components (in mixed-use or residential-only projects) must meet specified parking/density placement rules (§ 18.08.040).

  • Open Space districts (OS‑A/OS‑P/OS‑C)

    • Height limit is 16 ft in OS districts, with large setbacks from residential edges and coastal resources (e.g., 100 ft from any adjacent residential district; additional buffers to beaches/bluffs/trails) (§ 18.12.025(A)–(B)).

  • Variations, exceptions, and nonconformities

    • Residential exceptions may allow added height (with findings that bulk doesn’t increase FAR and public views are improved), FAR exceptions (neighborhood-scale findings), and targeted setback encroachments for small accessory structures, bay windows, and trellises (§ 18.06.050).
    • Commercial exceptions address legal nonconforming parcels, map‑related lot splits, height (chimneys), and carefully bounded parking exceptions when justified (Downtown and C‑R) (§ 18.07.045; similar provisions in § 18.08.045 for C‑G/C‑VS).
    • See Half Moon Bay Development Standards and Half Moon Bay Variances and Exceptions for orientation.

Sample summary of numeric baselines (confirm your exact district):

  • The R‑1 district: 20 ft front, 5 ft side, 20 ft rear; 28 ft max multi‑story height; 35% coverage; 0.5 FAR (§ 18.06.030).
  • The R‑3 district: 20 ft front, 5 ft side, 20 ft rear; 40 ft max multi‑story height; 45% multi‑story coverage; open space 15% of unit floor area (§ 18.06.030; § 18.06.040(A)).
  • The C‑G district: 25 ft front; 10 ft side/rear; 36 ft/3‑story height; 10% site landscaping (§ 18.08.040).

Specific plans & overlays

  • Downtown Historic District/Specific Plan influence
    • The C‑D/C‑R framework explicitly implements the Downtown Historic District Specific Plan: it emphasizes compatible scale, on‑site parking management, mixed use, and protection/adaptive reuse of historic structures (§ 18.07.010). Heritage Main Street ground-floor depth controls apply between Pilarcitos Creek and Correas Street (§ 18.07.025).
  • Coastal overlays and resource maps
    • Development commonly requires a Coastal Development Permit (CDP) per Chapter 18.20; local coastal resource maps may be amended like zoning maps (§ 18.38.025). See Half Moon Bay Overlay Districts.
  • Upland slopes/hillsides
    • Upland slope standards require clustering, avoidance of significant grading, keeping structures below the ridgeline as viewed from Highways 1 and 92, preserving trees, and—in specified PUDs—prohibiting development above the 160‑ft contour and on ≥25% slopes (§ 18.37.035).
  • Reserve districts (U‑R/OS‑R)
    • These hold lands in agricultural/open uses until urban services and LCP policies allow conversion; conversions to PUD require certified LCP amendments and sequencing so urban areas develop first (§ 18.11.010; § 18.11.030).

Building permits & review

  • Building permits are required for essentially all construction, remodels, and additions (fences under the height threshold are exempt). Residential threshold: fences ≤ 7 ft and decks < 18 in are exempt (§ 18.06.080(A)); commercial threshold: fences not exceeding allowed height (§ 18.07.060(A); § 18.08.060(A)). Building permits must comply with the California Building Standards Code (§ 18.06.050(A)(1)).
  • Coastal development permits (CDP): Required unless an exemption applies; the CDP chapter governs applicability, exemptions, notice/hearings, findings, and appeals (§ 18.20.010–.090; permit trigger at § 18.20.025).
  • Design review: Architectural/site design review must be completed before a building permit where required (§ 18.06.080(C); § 18.07.060(C); § 18.08.060(C)). See Half Moon Bay Design Review.
  • Use permits: Certain uses require a Planning Commission use permit under Chapter 18.22 (referenced throughout the use regulations; see § 18.07.025; § 18.08.025).
  • Parking compliance: Provide an off‑street parking plan per code; standards and any exceptions are applied during review (§ 18.08.030(E); § 18.07.045(E); § 18.08.045(E)). See Half Moon Bay Parking.
  • Signs and landscaping: New signs are reviewed/approved per Titles 15 and 18; landscaping plans are typically required for commercial and multifamily projects (§ 18.08.030(F), (G); § 18.06.040(B)). See Half Moon Bay Signage and Half Moon Bay Landscaping and Screening.

State housing law in Half Moon Bay

ADUs and JADUs (local standards aligned to Gov. Code 65852.2/.22)

  • Where allowed: In R‑1, R‑2, R‑3, C‑D, C‑R, C‑VS, C‑G, and certain PUD areas (§ 18.33.030(A)(1); § 18.33.040(A)).
  • Ministerial “streamlined” approvals:
    • Within existing space (single‑family): allowed with independent exterior access; minimal setbacks sufficient for fire/safety; plus JADUs per state law (§ 18.33.030(A)(4)–(7)).
    • Detached, new single‑family ADU: up to 800 sf, ≤16 ft height, 4 ft side/rear setbacks (§ 18.33.030(B)(6)).
    • Multifamily conversions: inside non‑habitable areas, up to 25% of existing unit count (min one unit) (§ 18.33.030(C)(4)).
    • Multifamily detached: up to two detached ADUs at ≤16 ft and 4 ft side/rear setbacks (§ 18.33.030(D)(4)–(6)).
  • Citywide ADU size and design caps: ≤850 sf (studio/1‑bed) or ≤1,000 sf (2+ bed); standards cannot reduce below 800 sf or below 16 ft height; no passageway required (§ 18.33.040(E)–(G)).
  • Setback flexibility and envelopes: side/rear may be 4 ft; other standard setbacks apply; building‑to‑building separation ≥6 ft unless fire mitigation; FAR/lot coverage cannot be used to cut an 800‑sf unit (§ 18.33.040(D)(1)–(3), (F)).
  • Coastal permitting for ADUs:
    • Some attached/within‑existing‑structure ADUs are exempt from CDP; others require an administrative CDP issued by the Community Development Director with post‑issuance agenda listing; no hearing is required; action generally within 60 days of a complete application unless the Coastal Act requires otherwise (§ 18.33.020(A)(2)–(4)).
  • Special local note: In Ocean Colony, ADUs/JADUs are not permitted in garages when created within existing space (§ 18.33.030(A)(4)).

See Half Moon Bay ADUs and California ADU law. For other state housing programs (e.g., SB 9 lot splits, density bonus), see California housing laws. Not found in source materials: Half Moon Bay–specific SB 9 or density bonus procedures—verify with the jurisdiction.

Information that behaves like overlays

  • Downtown historic resources: Chapter 18.07 includes “Historic downtown area, structures and uses” at § 18.07.055, indicating added considerations for heritage properties (details not provided in source). See Half Moon Bay Historic Preservation.
  • Coastal resource conservation and OS siting/buffering standards function as coastal overlays (§ 18.12.025; § 18.38.025; Chapter 18.20).

Source References

Where to read the Half Moon Bay code

The Half Moon Bay municipal and zoning code is published on eCode360 — view the official Half Moon Bay code library. That lets you read the ordinance section by section.

Want the ordinance itself? Read the full Half Moon Bay code text — every chapter and section, verbatim and searchable, in the GoCodebook Code Library.

GoCodebook goes beyond browsing eCode360 (see how they compare): it reads the Half Moon Bay ordinance together with the California Building Standards Code and answers your question — zoning, setbacks, FAR, height, ADUs, permits — with the controlling citation for your parcel.

Who this affects

Half Moon Bay homeownersReal estate developersArchitects & designersReal estate agentsInvestorsGeneral contractorsADU buildersPermit consultants

Frequently asked questions

What zoning districts does Half Moon Bay have?

Half Moon Bay establishes residential (R‑1/R‑2/R‑3), commercial (C‑D/C‑R/C‑G/C‑VS), employment (IND/PS), resource (OS‑A/OS‑P/OS‑C), reserve (U‑R/OS‑R), agricultural (A‑1/A‑2), PUD, and MHP districts. The official list is in § 18.01.015.

How are zoning district boundaries determined on the map?

If a boundary follows a street or lot line, read it along that line; otherwise, use the map scale. If uncertainty remains, the Planning Commission determines the line considering map location and district purposes (§ 18.01.030).

Do I need a coastal development permit (CDP) for my project?

Most new development in the Coastal Zone requires a CDP under Chapter 18.20. The code details applicability, exemptions, and process; the basic permit requirement is at § 18.20.025 (with general applicability at § 18.20.015).

What are the base R‑1 development standards?

Typical R‑1 lots require a front setback of 20 ft, side 5 ft (with combined side yards of 20% of lot width), rear 20 ft, a max multi‑story height of 28 ft, max multi‑story coverage 35%, and 0.5 FAR (§ 18.06.030, Table B).

What are the standards in the C‑G (General Commercial) district?

Minimum lot 10,000 sf and 100 ft width; 25 ft front and 10 ft side/rear setbacks; 36 ft/3‑story height limit; 10% site landscaping; and specific parking/density rules for residential/mixed-use components (§ 18.08.040).

How does Downtown “Heritage Main Street” regulate ground-floor uses?

Within the first 50 ft of ground-floor depth between Pilarcitos Creek and Correas Street, certain office uses are prohibited and many maker/repair/art uses must be ancillary or active ground-floor dependent to keep a vibrant storefront mix (§ 18.07.025, including A‑19, A‑20, A‑21(a)).

How do ADUs work in Half Moon Bay?

ADUs are allowed across residential and several commercial districts. Streamlined detached ADUs up to 800 sf, ≤16 ft tall with 4 ft side/rear setbacks are ministerial; conversions within existing space are also eligible. Some ADUs require an administrative CDP; action is generally within 60 days of a complete application (§ 18.33.030; § 18.33.040; § 18.33.020).

Can I get a parking reduction?

Parking exceptions can be approved case-by-case for Downtown/C‑R and C‑G/C‑VS projects if standards are as close as feasible and findings show no detriment (or historic preservation benefit). New construction must still meet parking unless an exception is granted (§ 18.07.045(E); § 18.08.045(E)).

Is there citywide rent control or SB 9 lot-split guidance?

Not found in source materials. Verify with the jurisdiction for any rent stabilization, SB 9 implementation, or density bonus procedures. See also California housing laws.

Do I need design review before my building permit?

If your project type triggers architectural/site design review, it must be completed before the building permit is issued in residential and commercial districts (§ 18.06.080(C); § 18.07.060(C); § 18.08.060(C)).

General information, not legal advice.

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