Local zoning · Marin County

Marin County — Land Use

Land Use under the Marin County local zoning and planning code, with the controlling citations.

Last reviewed: July 6, 2026

Overview

This page explains how land uses are assigned and regulated in unincorporated areas of Marin County under the County’s zoning/planning ordinance. Within the Coastal Zone, Marin codifies zoning and allowed uses in Title 20 of the Coastal Zoning Code, which implements the certified Local Coastal Program; inland areas rely on Title 22 (Development Code). Allowed uses in each coastal district are shown in tables and labeled PP (principal permitted), P (permitted), or U (conditional) per § 20.62.040, and uses not listed are not allowed. A Coastal Development Permit is often required in addition to any other local approvals.

In Marin’s Coastal Zone, a use is only allowed if it appears in the district’s land use table; anything not listed is prohibited, and most development requires a Coastal Development Permit. See § 20.62.040 and § 20.68.030.

Before you plan a project, confirm your parcel’s district on the official map (adopted in Title 22) and review the Marin County Zoning and Marin County Development Standards pages. If your proposal triggers review, you may also need Marin County Design Review in addition to any Coastal Development Permit noted below.

How the code organizes “allowed uses” (Coastal Zone)

Districts are established in § 20.62.030 and grouped as Agricultural/Resource (e.g., C-APZ, C-ARP, C-OA), Residential (e.g., C-RA, C-R1, C-R2, C-RSP, C-RSPS, C-RMP), and Commercial/Mixed-Use (e.g., C-VCR, C-H1, C-CP, C-RMPC, C-RCR), with Special Purpose/Combining districts like C-PF and the “-B” Coastal Minimum Lot Size overlay.
Each table shows whether a use is PP, P, or U. Principal permitted uses (PP) and permitted uses (P) still must meet all applicable standards; conditional uses (U) require a use permit per Chapter 22.48. Uses not listed are not allowed (§ 20.62.040.B).
Unless exempt or categorically excluded, development in the Coastal Zone needs a Coastal Development Permit (§ 20.68.030), and some uses may also require a Master Plan (§ 20.62.040.C).

District-by-District Standards (Coastal Zone)

C-APZ — Coastal, Agricultural Production Zone

Purpose and where it applies: Protects agricultural lands consistent with the Agriculture 1 category of the Land Use Plan, in unincorporated Coastal Zone areas. Density is capped at 1 unit per 60 acres (maximum, not entitlement).
Typical allowed uses: Agricultural production and accessory structures (PP), one farmhouse and, in some cases, intergenerational homes and agricultural worker housing; certain non-ag uses may be conditional. See Table 5‑1 for details.
Key dimensional notes: Agricultural dwelling sizes and clustering are governed by coastal standards; see § 20.65.040 references and the size/density notes under § 20.64.045 and § 20.32.024–.030. Verify parcel-specific standards.

C-ARP — Coastal, Agricultural, Residential Planned

Purpose and where it applies: For lands adjacent to residential areas that still support agriculture; requires clustering to maximize land retained for agriculture. Agriculture is the PP use in C‑AG1/2 mapped areas; residential is PP in C‑AG3 (§ C‑AG‑3 policy).
Typical allowed uses: Agricultural accessory activities (PP); farmhouses and small-scale agricultural processing may be PP or U depending on size; guest houses and ADUs can be allowed; see Table 5‑1.
Key dimensional notes: Clustering and community standards apply; confirm any “-B” overlay setbacks if mapped (§ 20.64.040).

C-OA — Coastal, Open Area

Purpose and where it applies: Open space and outdoor recreation lands in the Coastal Zone (e.g., park, beach access, natural drainage).
Typical allowed uses: Nature preserves (P), public recreation, some utilities (U), marinas/harbors (U). See Table 5‑1.
Key dimensional notes: Governed by coastal resource standards in Chapter 20.64; verify site-specific setbacks.

C-RA — Coastal, Residential, Agricultural

Purpose and where it applies: Single-family residential in an agricultural context.
Typical allowed uses: Single-family dwellings (PP), ADUs (PP), guest houses (P), small-scale agriculture and home occupations (P). See Table 5‑2.
Key dimensional notes: Base setbacks and heights may be controlled by a mapped “-B” overlay; otherwise see § 20.64.045 for general property development and use standards (setback measurement, height rules).

C-R1 — Coastal, Residential, Single-Family

Purpose and where it applies: Detached single-family areas in the Coastal Zone.
Typical allowed uses: Single-family dwellings (PP), ADUs (PP), guest houses (P); two-family is not allowed here. Table 5‑2.
Key dimensional notes: “-B” overlay standards, if applied, set minimum lot area, setbacks, and height.

C-R2 — Coastal, Residential, Two-Family

Purpose and where it applies: Two-family areas; allows single-family consistent with multi-family policy cross-references.
Typical allowed uses: Two-family dwellings (PP), single-family (PP), ADUs (PP).
Key dimensional notes: See mapped “-B” overlay for specific lot size/setbacks; general standards in § 20.64.045.

C-RSP — Coastal, Residential, Single-Family Planned

Purpose and where it applies: Planned single-family areas emphasizing sensitive site design; this section “establishes no specific setback requirements.”
Typical allowed uses: Single-family (PP), ADUs (PP), guest houses (P). Table 5‑2.
Key dimensional notes: On Tomales Bay shoreline, height is limited to 15 ft (§ 20.65.060.C).

C-RSPS — Coastal, Residential, Single-Family Planned (Seadrift Subdivision)

Purpose and where it applies: Seadrift Subdivision at Stinson Beach.
Typical allowed uses: Single-family (PP), ADUs (PP), guest houses (P). See Table 5‑2.
Key dimensional notes: Ocean setbacks fixed by recorded subdivision maps/CC&Rs; NAVD-based height caps apply (finished floor 19.14 ft NAVD in specified areas; total height 34.14 ft NAVD, subject to FEMA constraints) (§ 20.65.070.C–D).

C-RMP — Coastal, Residential, Multiple Planned

Purpose and where it applies: Planned multi-family areas.
Typical allowed uses: Multi-family dwellings (PP), ADUs (PP), residential accessory uses (PP). Table 5‑2.
Key dimensional notes: Planned district standards and any mapped “-B” overlay control site development.

C-VCR — Coastal, Village Commercial/Residential

Purpose and where it applies: Mixed commercial/residential village settings.
Typical allowed uses: Plant nurseries (P), agricultural production (P), mariculture (P), recycling reverse vending (P); some production uses (U). Table 5‑3.
Key dimensional notes: Governed by coastal development and community standards; verify local community standards in Chapter 20.66.

C-H1 — Coastal, Limited Roadside Business

Purpose and where it applies: Rural roadside commercial nodes serving motorists.
Typical allowed uses: Similar to C‑VCR with emphasis on small-scale roadside services; see Table 5‑3 for specific PP/P/U entries.
Key dimensional notes: See Chapter 20.64 and any community standards that apply.

C-CP — Coastal, Planned Commercial

Purpose and where it applies: Full range of commercial/institutional uses consistent with the LCP.
Typical allowed uses: Nurseries (P), mariculture (P), certain manufacturing/processing (U). Table 5‑3.
Key dimensional notes: Planned district standards; confirm any “-B” overlay.

C-RMPC — Coastal, Residential/Commercial Multiple Planned

Purpose and where it applies: Mixed-use with residential and commercial.
Typical allowed uses: Mix of residential and commercial per Table 5‑3 (some uses U).
Key dimensional notes: Planned district standards/overlays govern site design.

C-RCR — Coastal, Resort and Commercial Recreation

Purpose and where it applies: Resort facilities and public access-oriented recreation/commercial.
Typical allowed uses: Recreation-oriented commercial; see Table 5‑3.
Key dimensional notes: Coastal resource and hazard standards in Chapter 20.64.

C-PF — Coastal, Public Facilities

Purpose and where it applies: Governmental/educational and similar public facilities; may be a primary zoning or a combining district.
Typical allowed uses: Public facilities and institutions consistent with LCP.
Key dimensional notes: See Chapter 20.64 and applicable community standards.

-B — Coastal Minimum Lot Size Combining District

Purpose and where it applies: Establishes minimum lot area, setbacks, and heights in mapped coastal areas; supersedes primary district standards when applied (§ 20.64.040).

Table: Selected “-B” Combining District Standards (Coastal)

Overlay	Minimum Lot Area	Example Minimum Setbacks	Max Height (primary)	Max FAR	Code Reference
B1	6,000 sq ft	Front 25 ft; Sides 5 ft (10 ft street side); Rear: 20% of lot depth up to 25 ft	25 ft (15 ft accessory)	0.30	§ 20.64.040, Table 5‑5; note Stinson Beach Highlands primary height 17 ft per § 20.64.045(3) note
B3	20,000 sq ft	Front 30 ft; Sides 15 ft	25 ft	n/a	§ 20.64.040, Table 5‑5
BD (Dillon Beach)	See Dillon Beach Community Standards	Front 10 ft; Sides 5 ft (10 ft street side); Rear 10 ft	20 ft	FAR exempt	§ 20.66.110.B; § 20.64.040/Table 5‑5 (BD)

Related coastal measurement rules and exceptions appear in § 20.64.045 (Property Development and Use Standards), including how setbacks are measured and when exceptions may apply.

Coastal Residential Allowed Uses (selected)

Use	C‑RA	C‑R1	C‑R2	C‑RSP	C‑RSPS	C‑RMP	Code Reference
Single-family dwellings	PP	PP	PP	PP	PP	PP	§ 20.62.070; Table 5‑2
Two-family dwellings	—	—	PP	—	—	PP	Table 5‑2‑c
ADUs	PP	PP	PP	PP	PP	PP	Table 5‑2‑c; § 20.32.140
Guest houses	P	P	P	P	P	P	Table 5‑2‑c; § 20.32.090
Home occupations	P	P	P	P	P	P	Table 5‑2‑c; § 20.32.100
Multi-family dwellings	—	—	—	—	—	PP	Table 5‑2‑c

For parking, sign, and site design requirements that apply alongside land-use approvals, see Marin County Parking, Marin County Signage, and Marin County Landscaping and Screening.

Cross-cutting coastal rules you’ll see in most projects

Coastal Development Permit: Required unless exempt/categorically excluded (§ 20.68.030). Some decisions are appealable to the Coastal Commission per § 20.62.040.B and the LCP definitions of “Appealable Development.”
Design Review: The LCP notes that design review lives in Title 22.42 and applies independently of Coastal permits. Coordinate early with Marin County Design Review.
Master Plans: Required for certain larger/special uses (e.g., marinas, cemeteries, mineral extraction, airparks, waste disposal sites) per § 20.62.040.C.
Variances: Some height exceedances need a Coastal Zone Variance (e.g., over 25 ft in certain areas) per § 20.64.045 notes and § 20.70.150; see Marin County Variances and Exceptions.

If an existing use doesn’t conform to today’s land-use tables, see Marin County Nonconforming Uses. If an improvement implicates building safety standards, those are addressed under the California Building Standards Code page, separate from land-use controls. For state housing mandates affecting residential uses, see California housing laws and California ADU law.

Checklist

Confirm parcel is in unincorporated Marin and whether it is in the Coastal Zone; identify the base zoning district and any “-B” or other overlays on the official map (referenced in § 20.62.030).
Find your use in the applicable land-use table (Tables 5‑1, 5‑2, or 5‑3) and note PP/P/U and any cross-referenced standards.
Check if a Coastal Development Permit is required; confirm exemptions or categorical exclusions (§ 20.68.030).
If in a planned district or community with special standards (e.g., C‑RSP on Tomales Bay; C‑RSPS in Seadrift; Dillon Beach), apply those dimensional limits.
If a “-B” overlay is mapped, use Table 5‑5 for minimum lot area, setbacks, and height.
Verify whether Design Review (Title 22.42) applies in addition to coastal permits (noted in LCP tables).
Confirm parking, landscaping, signage, and other site standards that also apply to your use. See linked pages.

Risks & Ambiguities

Issue	Why it matters	What to verify
Use not listed in table	Unlisted uses are prohibited in coastal districts (§ 20.62.040.B.4)	Whether a close “use classification” exists in Tables 5‑1/5‑2/5‑3; otherwise, not allowed.
Coastal Development Permit appealability	Some approvals are appealable to the Coastal Commission	Whether the project is a PP use outside appeals areas; check “Appealable Development” thresholds.
Dimensional rules vary by overlay/community	“-B” standards and community-specific caps (e.g., Dillon Beach; Stinson Beach Highlands) can supersede general rules	Whether a “-B” or community standard applies; confirm Table 5‑5 notes and § 20.66.110.
Planned districts with “no specific setbacks”	C‑RSP/C‑RMP rely on sensitive-site planning vs. fixed yard rules	Project-specific siting will be scrutinized; apply § 20.64.045 and any community/hazard resource standards.
Agricultural housing counts/density	Worker housing caps and APZ density can constrain design	Whether housing fits within § 20.32.030 thresholds and APZ 1/60‑ac max density; clustering may be required.
Seadrift NAVD height rules	Heights keyed to finished floor and FEMA minimums	The correct NAVD datum, plat, and FEMA requirement for the lot.

Plain-English Summary

In unincorporated coastal Marin, every parcel sits in a zoning district that lists exactly which land uses are allowed and how they’re permitted. Find your district, look up your use in the table, then apply any overlay/community standards and get a Coastal Development Permit if required; if the use isn’t listed, it’s not allowed.

Source References

§ 20.62.020 Applicability; § 20.62.030 Districts Established; § 20.62.040 Allowable Land Uses and Permit Requirements; § 20.62.050 Zoning District Regulations.
Tables 5‑1 (Agricultural/Resource), 5‑2 (Residential), 5‑3 (Commercial/Mixed-Use).
§ 20.64.040 Coastal Minimum Lot Size (-B) Combining District; Table 5‑5; § 20.64.045 Property Development and Use Standards.
§ 20.65.060 C‑RSP Height (Tomales Bay); § 20.65.070 C‑RSPS (Seadrift) Standards.
§ 20.66.110 Dillon Beach Community Standards.
§ 20.68.030 Coastal Development Permit Required.

Information Gaps

Inland (non-coastal) zoning district land-use tables and dimensional standards: Not found in retrieved materials.
Full coastal commercial retail/office use listings beyond the provided manufacturing/processing excerpt: Not found in retrieved materials.
Complete text of § 20.65.040 (C‑APZ detailed dimensional standards): Not found in retrieved materials.
For all items above, verify with the jurisdiction.

Sources

Retrieved passages

Marin County Zoning Code (Chapter 22.48) High relevance
Marin County Zoning Code (Chapter 20.130) High relevance
Marin County Zoning Code (Section 22.62.040.B) High relevance
Marin County Zoning Code (Chapter 20.130.) High relevance
Marin County Zoning Code (Chapter 22.48) Medium relevance
Marin County Zoning Code (§ III) Medium relevance
Marin County Zoning Code (Chapter 20.62) Medium relevance
Marin County Zoning Code (Chapter 20.130) Medium relevance
Marin County Zoning Code (Section 20.62.040) High relevance
Marin County Zoning Code (Section 20.65.070.D) Medium relevance
Marin County Zoning Code (Chapter apply) Medium relevance
Marin County Zoning Code (§ III) Medium relevance
Marin County Zoning Code (Chapter 22.48) Medium relevance

Cited sections

Official Marin County code library

Frequently asked questions

What can I build on a C-R1 lot in unincorporated coastal Marin?

C‑R1 primarily allows a single-family home as a principal permitted use, with ADUs also allowed. Guest houses are permitted, and two-family dwellings are not allowed in C‑R1. Always confirm any “-B” overlay setbacks/heights that may apply. See Table 5‑2 and § 20.62.070.

Are ADUs allowed in coastal residential districts?

Yes. ADUs are listed as permitted or principal permitted in coastal residential districts including C‑RA, C‑R1, C‑R2, C‑RSP, C‑RSPS, and C‑RMP. Apply coastal standards and any community/overlay rules. See Table 5‑2‑c and § 20.32.140.

Do I need a Coastal Development Permit for a house in the Coastal Zone?

Generally yes, unless your project is exempt or categorically excluded. § 20.68.030 states a Coastal Development Permit is required for development in the Coastal Zone; appealability depends on location and whether the use is principal permitted.

What’s allowed in the C-APZ agricultural zone?

Agricultural production and accessory uses are principal permitted; a farmhouse and certain intergenerational/worker housing are allowed within limits. Other uses, like agricultural homestays or larger processing, can be conditional. See Table 5‑1 and APZ standards. Density is limited to 1 unit/60 acres.

How are setbacks and heights determined in coastal residential areas?

If a “-B” overlay is mapped, Table 5‑5 sets minimum lot area, setbacks, and heights (e.g., B1 front yard 25 ft, primary height 25 ft). Some communities have their own caps (e.g., Dillon Beach 20‑ft max height). Where planned districts set “no specific setbacks,” apply § 20.64.045 and community standards.

Can I open a small shop in a coastal village?

In C‑VCR (Village Commercial/Residential), many agricultural/greenhouse-related uses are P, and some small production uses are U; detailed retail/office listings are in Table 5‑3. Development must also meet coastal community standards. Verify your specific use is listed.

Are guest houses and home occupations allowed?

Yes, guest houses are typically P and home occupations are P across coastal residential districts, subject to standards. See Table 5‑2 and §§ 20.32.090, 20.32.100.

What happens if my existing use isn’t allowed today?

It may be a nonconforming use. Changes or expansions are limited; see the County’s nonconforming regulations and confirm with staff. Uses not listed in the land-use tables are not allowed (§ 20.62.040.B.4).

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