Local zoning · Marin County

Marin County — Zoning

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

Last reviewed: July 6, 2026

Overview

In unincorporated areas of Marin County, zoning is governed by the Marin County Code. Properties inside the Coastal Zone follow the certified Local Coastal Program in Title 20 (Coastal Zoning Code); properties outside it follow the County’s Development Code in Title 22. The Coastal Zoning Code establishes the coastal zoning districts, allowed uses, and how to read the official Zoning Map referenced in the Development Code. Always confirm whether a parcel lies in the Coastal Zone; the applicable title determines the districts and standards that apply in unincorporated areas (see § 20.62.020 and § 20.62.030, which references § 22.06.030) .

The Coastal Zoning Code divides unincorporated coastal lands into specific base districts (e.g., C-APZ, C-R1, C-VCR) shown on the official Zoning Map; uses are coded as PP (principal permitted), P (permitted), or U (use permit) and may require a Coastal Development Permit per § 20.62.040 .

Use this page together with the Marin County Land Use, Marin County Development Standards, Marin County Design Review, Marin County Parking, and Marin County Overlay Districts guides.

How the Coastal Zoning Code works (unincorporated Coastal Zone)

Districts established and mapped: § 20.62.030 (district list; Zoning Map is adopted by § 22.06.030) .
Allowable uses and permit types: § 20.62.040 (PP/P/U; CDP triggers) and Tables 5-1, 5-2, 5-3 by district .
Development standards and measurements (height, FAR, coverage, setbacks) are in Chapter 20.64; see § 20.62.050.C and § 20.64.010–.030 .
Parcels in multiple districts: § 20.62.050.B (Director review for potential rezoning on consolidation) .
Special/combining districts (e.g., C-PF, -B Minimum Lot Size) are in § 20.62.090; the -B district’s purpose is cross-referenced to § 20.64.040 .

Quick-view: Coastal Zoning Districts (unincorporated areas)

District	Core purpose / where applied	Typical allowed uses (examples)	Key dimensional standards	Code Reference
C-APZ (Coastal, Agricultural Production Zone)	Protects working ag lands, large parcel agriculture; consistent with Agriculture 1 LUP areas	Agricultural production and accessory agricultural uses are typically PP; processing may be PP/U by size; see Table 5-1	Max residential density typically 1 unit/60 acres; development standards in Ch. 20.64	§ 20.62.060.B.1; Table 5-1; density note
C-ARP (Coastal, Agricultural, Residential Planned)	Edge-of-town ag and clustered residential; requires clustering to keep ag land open	Mix of agriculture and residential; many ag accessory uses PP; see Table 5-1	Development must cluster; standards in Ch. 20.64	§ 20.62.060.B.2; Table 5-1
C-OA (Coastal, Open Area)	Open space, recreation, beach access corridors	Open space/recreation; limited marinas/harbors U; see Table 5-1	Standards in Ch. 20.64	§ 20.62.060.B.3; Table 5-1
C-RA (Coastal, Residential, Agricultural)	Low-density residential with small-scale ag	Single-family, ag accessory, homestays by type; see Table 5-2	Standards in Ch. 20.64	§ 20.62.070.B.1; Table 5-2
C-R1 (Coastal, Residential, Single-Family)	Detached single-family neighborhoods	Single-family dwellings; see Table 5-2	Standards in Ch. 20.64	§ 20.62.070.B.2; Table 5-2
C-RSP (Coastal, Residential, Single-Family Planned)	Planned single-family areas tailored to sensitive sites	Similar to C-R1 but site-tailored forms; Table 5-2	No fixed setbacks; site-responsive design; standards in Ch. 20.64	§ 20.62.070.B.3; Table 5-2
C-RSPS (Coastal, Residential, Single-Family Planned, Seadrift)	Seadrift sandspit/lagoon area with unique hazards and public access conditions	Single-family consistent with LCP; Table 5-2	Special ocean setbacks; finished floor and total height caps (e.g., max 34.14 ft NAVD in specified areas); see § 20.65.070	§ 20.62.070.B.4; § 20.65.070; Table 5-2
C-R2 (Coastal, Residential, Two-Family)	Duplex and compatible forms	Two-family, single-family (per policy), related uses; Table 5-2	Standards in Ch. 20.64	§ 20.62.070.B.5; Table 5-2
C-RMP (Coastal, Residential, Multiple Planned)	Planned multi-family forms	Varied residential types per LCP; Table 5-2	No fixed setbacks; site-responsive; Ch. 20.64	§ 20.62.070.B.6; Table 5-2
C-VCR (Coastal, Village Commercial/Residential)	Village main streets; resident- and visitor-serving mix	Commercial is often PP in mapped village cores with upper-floor residential P; outside cores, residential may be PP; see Table 5-3 notes	Standards in Ch. 20.64; storefront continuity standards for mixed use	§ 20.62.080.B.1; Table 5-3 and Notes (3)–(4)
C-H1 (Coastal, Limited Roadside Business)	Rural highway-serving uses	Roadside/motoring services; see Table 5-3	Standards in Ch. 20.64	§ 20.62.080.B.2; Table 5-3
C-CP (Coastal, Planned Commercial)	Full range commercial/institutional in LCP areas	Broad commercial lists; see Table 5-3	Standards in Ch. 20.64	§ 20.62.080.B.3; Table 5-3
C-RMPC (Coastal, Residential/Commercial Multiple Planned)	Planned mixed-use residential/commercial	Mixed residential/commercial; see Table 5-3	Standards in Ch. 20.64	§ 20.62.080.B.4; Table 5-3
C-RCR (Coastal, Resort & Commercial Recreation)	Visitor-serving resort and recreation	Resort/recreation emphasis with public access; Table 5-3	Standards in Ch. 20.64	§ 20.62.080.B.5; Table 5-3
C-PF (Coastal, Public Facilities)	Public/institutional sites in Coastal Zone	Public facilities consistent with LUP	Standards in Title 20; may be primary or combining	§ 20.62.090.B.2
-B (Coastal, Minimum Lot Size combining)	Adds minimum lot size overlay to a base district	N/A (combines with a primary zone)	See purpose/applicability in § 20.64.040	§ 20.62.090.B.3

Notes on allowed-use symbols and permits in Coastal Zone:

PP = principal permitted use (generally protected and prioritized); P = permitted; U = conditional (Use Permit). See § 20.62.040 and the “Key to Permit Requirements” in the district tables .
CDP basics: Certain coastal projects need a Coastal Development Permit; principal permitted uses are prioritized; “P” and “U” uses still require CDP if not exempt; appeals rules differ by use type. See § 20.62.040 and explanatory notes at Table 5-1/5-3 headers .

Agricultural and Resource-Related Districts (Coastal)

C-APZ. Protects long-term agriculture; typical PP uses include agricultural production, accessory structures, small processing; density generally capped at 1 dwelling per 60 acres. Standards and calculations are in Chapter 20.64; see Table 5-1 for use specifics (§ 20.62.060.B.1 and Table 5-1) .
C-ARP. Requires clustering to conserve ag soils and habitat; mix of agricultural and residential allowed as specified in Table 5-1; development must cluster per LCP policy (§ 20.62.060.B.2) .
C-OA. Open space/recreation and connections to beaches and natural drainage; select water-related facilities may be U uses; see Table 5-1 (§ 20.62.060.B.3) .

Residential Districts (Coastal)

C-RA. Single-family with small-scale agriculture; see Table 5-2 for PP/P/U and Chapter 20.64 for standards (§ 20.62.070.B.1) .
C-R1. Single-family; see Table 5-2 (§ 20.62.070.B.2) .
C-RSP. Planned single-family; no fixed setbacks—design must fit site conditions; see Table 5-2 and Ch. 20.64 (§ 20.62.070.B.3) .
C-RSPS (Seadrift Subdivision). Planned single-family at Seadrift; no fixed setbacks in § 20.62.070, but with unique ocean setbacks and elevation/height caps in § 20.65.070 (e.g., finished floor typically ≤ 19.14 ft NAVD in identified areas; overall height ≤ 34.14 ft NAVD, with FEMA-related adjustments) .
C-R2. Two-family districts; attached duplexes and related uses; see Table 5-2 (§ 20.62.070.B.5) .
C-RMP. Planned multi-residential; site-responsive design; see Table 5-2 (§ 20.62.070.B.6) .

Accessory Dwelling Units: ADUs in coastal residential districts are addressed under Chapter 20.32 (Standards for Specific Land Uses), and must conform to zoning standards; additional ministerial permitting under Title 22 may apply. Verify CDP applicability per § 20.62.040 and see state guidance in California ADU law .

Commercial and Mixed-Use Districts (Coastal)

C-VCR. Village commercial/residential; in mapped village cores, commercial is the principal permitted use and residential is permitted on upper floors or off the road-facing frontage; outside the core, residential may be principal permitted (see Table 5-3 Notes (3)-(4)) (§ 20.62.080.B.1) .
C-H1. Limited roadside business serving the motoring public (§ 20.62.080.B.2) .
C-CP. Planned commercial for a full range of LCP-consistent commercial/institutional uses (§ 20.62.080.B.3) .
C-RMPC. Planned mixed-use residential/commercial (§ 20.62.080.B.4) .
C-RCR. Resort and commercial recreation with an emphasis on public access (§ 20.62.080.B.5) .

Use tables and standards: Allowable uses and PP/P/U keys are in Table 5-3; dimensional and design standards are in Chapter 20.64 (§ 20.62.080.C–D) .

Special Purpose and Combining (Coastal)

C-PF (Coastal Public Facilities). May be applied as a primary or combining district to public/institutional sites (§ 20.62.090.B.2) .
-B (Minimum Lot Size combining). Adds minimum lot size requirements; see applicability in § 20.64.040 (referenced by § 20.62.090.B.3) .

Zoning Map (applies countywide to unincorporated areas)

The Coastal Zoning Code states the official Zoning Map is adopted in the Development Code at § 22.06.030; districts established by § 20.62.030 are “shown on the official Zoning Map” (§ 20.62.030) . Use the map to determine if a site is in a coastal district versus an inland Title 22 district, then consult the matching standards and Overlay Districts.

Inland (non-Coastal) base zoning districts

Not found in retrieved materials. Title 22 (Development Code) governs inland districts, their permitted uses, and standards. Confirm the parcel’s zoning and consult Title 22 for inland zones, plus related processes like Design Review, Nonconforming Uses, Variances and Exceptions, and site Parking.

Checklist

Determine if the parcel is within the Coastal Zone (Title 20) or inland (Title 22) on the official Zoning Map referenced by § 20.62.030 .
Identify the base district (e.g., C-R1, C-VCR, C-APZ) and any combining district (e.g., -B) per § 20.62.030 and § 20.62.090 .
Check the district’s allowed uses and whether a use is PP, P, or U in the correct Table (5-1/5-2/5-3) per § 20.62.040 .
Review applicable development standards (height, setbacks, lot coverage, FAR, measurements) in Chapter 20.64 and any community-specific or planned-district standards (e.g., § 20.65.070 for Seadrift) .
Confirm whether Design Review applies in addition to zoning; table notes direct design review to Chapter 22.42 (not in LCP tables) (Table Notes; see § 20.62.080 tables/notes) .
If splitting or merging lots, check coastal land division criteria and clustering rules (e.g., § 20.70.190) .
For residential intensification (e.g., ADUs), verify standards in Chapter 20.32 and CDP triggers under § 20.62.040, and align with California ADU law .

Risks & Ambiguities

Issue	Why it matters	What to verify
Parcel spans multiple zoning districts	Different use/standard regimes could both apply	Director review for consolidated parcels; potential rezoning consideration under § 20.62.050.B; verify map boundaries
In-village vs. out-of-village C-VCR rules	Ground-floor residential limits differ in mapped village cores	Whether the site is inside the mapped C-VCR core; apply Table 5-3 Notes (3)-(4) under § 20.62.080
Seadrift (C-RSPS) hazard/elevation standards	Strict NAVD height/elevation controls affect design feasibility	The parcel’s Seadrift tract, FEMA base flood elevation, and the precise § 20.65.070 caps and setbacks
Agricultural density and clustering	Overbuilding can conflict with LCP agricultural protection	In C-APZ, apply the 1 unit/60 acres cap; in C-ARP, confirm clustering per § 20.62.060.B.1–2
Measurements and FAR calculations	Misapplied heights/coverage cause noncompliance	Use Chapter 20.64 for measurement methods; see § 20.62.050.C for where to find them
Whether a CDP is required	Coastal appeals and timing depend on CDP status	Apply § 20.62.040 and the PP/P/U framework; some decisions are appealable to the Coastal Commission (Table explanatory notes)

Plain-English Summary

If your unincorporated Marin County property is in the Coastal Zone, the Coastal Zoning Code (Title 20) sets your zoning district, what you can build, and the rules you must meet; if it’s inland, the County’s Development Code (Title 22) applies. Start by confirming the district on the official Zoning Map, then look up the allowed uses table and the development standards in Chapter 20.64. Special areas like Seadrift have their own height/elevation rules, village main streets have different mixed-use priorities, and agriculture has strict density and clustering protections; when in doubt, verify with the County.

Source References

§ 20.62.010–.040 (Purpose, applicability, coastal districts, allowable uses; CDP framework)
§ 20.62.050 (Coastal zoning regulations; measurements in Chapter 20.64)
§ 20.62.060 (Coastal Agricultural & Resource-Related Districts; C-APZ, C-ARP, C-OA) and Table 5-1
§ 20.62.070 (Coastal Residential Districts; C-RA, C-R1, C-RSP, C-RSPS, C-R2, C-RMP) and Table 5-2
§ 20.62.080 (Coastal Commercial/Mixed-Use Districts; C-VCR, C-H1, C-CP, C-RMPC, C-RCR) and Table 5-3 (incl. Notes)
§ 20.62.090 (Coastal Special Purpose and Combining Districts; C-PF, -B)
Chapter 20.64 (Coastal Zone Development & Resource Management Standards) and § 20.64.010–.030 (purpose/applicability/general standards)
§ 20.65.070 (C-RSPS Seadrift standards)
§ 20.70.190 (Land divisions in Coastal Zone)
Zoning Map adopted at § 22.06.030, as referenced by § 20.62.030 (Not found in retrieved materials for the text of § 22.06.030)

Information Gaps

Inland (non-Coastal) base zoning districts and their development standards: Not found in retrieved materials.
Text of § 22.06.030 (Zoning Map Adopted): Not found in retrieved materials.
Numeric coastal development standards by district in Chapter 20.64 (heights, setbacks, FAR) beyond Seadrift: Not found in retrieved materials.

Sources

Retrieved passages

Marin County Zoning Code (Chapter apply) High relevance
Marin County Zoning Code (§ III) High relevance
Marin County Zoning Code (Chapter 20.130) High relevance
Marin County Zoning Code (§ III) High relevance
Marin County Zoning Code (Section 20.62.040) High relevance
Marin County Zoning Code (Section 22.62.040.B) High relevance
Marin County Zoning Code (section shall) Medium relevance
Marin County Zoning Code (Section 20.64.040) Medium relevance

Cited sections

Official Marin County code library

Frequently asked questions

What can I build in a C-R1 lot in unincorporated Marin County’s Coastal Zone?

C-R1 is for detached single-family homes and related compatible uses. Check Table 5-2 for whether your use is principal permitted (PP), permitted (P), or conditional (U), and apply Chapter 20.64 for height, setbacks, and coverage. A Coastal Development Permit may be required under § 20.62.040 and § 20.62.070.B.2 .

How are setbacks handled in C-RSP and C-RMP planned residential coastal districts?

These planned districts intentionally do not set fixed setbacks so design can respond to sensitive site conditions. Use Chapter 20.64 for applicable development standards and verify any community standards. See § 20.62.070.B.3 and B.6 .

What’s special about the Seadrift (C-RSPS) zoning?

Seadrift has unique ocean-side setbacks and strict finished-floor and total height limits tied to NAVD elevations (e.g., finished floor often ≤ 19.14 ft NAVD; structure height ≤ 34.14 ft NAVD in specified tracts, with FEMA adjustments). See § 20.65.070 and § 20.62.070.B.4; verify your lot’s subdivision map and FEMA base flood elevations .

In C-VCR villages, can I put residential on the ground floor?

Inside mapped “village commercial core” areas, commercial is the principal permitted use, and residential is generally limited to upper floors or non-street-front ground-floor areas; outside the core, residential may be the principal permitted use. See Table 5-3 Notes (3)-(4) under § 20.62.080; verify whether your parcel is inside the mapped core .

How is agricultural housing or homestay handled in coastal ag districts?

Agricultural accessory uses and small homestays are generally allowed with PP/P/U designations depending on district and size; see Table 5-1 for specifics. Density in C-APZ is typically limited to 1 unit per 60 acres; clustering is required in C-ARP. See § 20.62.060 and Table 5-1 .

My parcel is split by two districts—what happens?

If parcels are consolidated and a resulting lot is covered by multiple districts, the Director may review whether rezoning to a single district is appropriate. See § 20.62.050.B and confirm current zoning map layers before designing .

Do I need a Coastal Development Permit if my use is “P” or “U”?

Often yes—“P” or “U” status in the use table doesn’t remove CDP requirements. The Coastal Zoning Code explains which permits apply (including appealability) in § 20.62.040 and associated table notes. Always confirm exemptions and appeal status before proceeding .

Where do I find the exact heights and setbacks for my coastal zone project?

Use Chapter 20.64 for development and measurement standards and any planned/community standards that apply. The Seadrift area is governed by § 20.65.070 for special elevation and height limits. See § 20.64.010–.030 and § 20.65.070 .

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