Bolthole Index

Contra Costa County, California

Building permits, zoning and land rules in Contra Costa County, California

27Index Score / 100
#49 of 58 in California

Unincorporated Contra Costa County, California requires permits for almost all building projects, with limited exemptions1. County zoning and adopted building codes apply, and parcel standards depend on the zoning district234. Building applications go through ePermits, while Contra Costa Health reviews plans for properties with septic systems or wells56.

At a glance

Building permit
Required for almost all projects in unincorporated areas; limited exemptions apply1
Zoning
County zoning applies to unincorporated parcels; cities administer their own zoning7
Septic permit
Contra Costa Health permits and inspects onsite wastewater work89
RV living
Sleeping in an RV is prohibited in unincorporated areas except under specific code-authorized uses10
Tiny home
Not recognized as a separate planning category; wheels are treated as an RV11
Owner-builder
Available conditionally, but not an exemption from permits or inspections12
Private well
A county permit and inspections are required for covered well work13
Septic soil suitability
Only 0.5% of mapped soil is free of severe limits for a conventional drain field14

Who to call

Building permits

Contra Costa County Department of Conservation and Development - Building Inspection

Building, grading and related permits and inspections for unincorporated Contra Costa County

925-655-2700

30 Muir Road, Martinez, CA 94553

Online permits →

Zoning

Contra Costa County Department of Conservation and Development - Planning Division

Zoning, planning applications and land-use review for unincorporated Contra Costa County

925-655-2774

30 Muir Road, Martinez, CA 94553

Online permits →

Septic permits

Contra Costa Health - Environmental Health Division

Septic construction permits, well permits, and site and soil evaluations through the Land Use Program

925-608-5500

2120 Diamond Boulevard, Suite 100, Concord, CA 94520

Floodplain permits

Contra Costa County Public Works Department - Floodplain Management Program

Floodplain permits and flood-hazard review for unincorporated Contra Costa County

925-655-2700

Roads & driveways

Contra Costa County Public Works Department - Encroachment Permits

Encroachment-permit questions for work affecting county roads

925-313-2000

Contact details are copied from each office’s official page and were checked against it on October 11, 2026.

Off-grid gear

Going off-grid in Contra Costa County means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Contra Costa County, California?

Yes. Almost all projects in unincorporated Contra Costa County require building permits, including new structures, additions, remodels, utilities, decks, garages, accessory dwelling units and generators1. The county lists the California building, residential, electrical, mechanical, plumbing, energy, fire and related codes among its current codes for unincorporated construction3. Limited exemptions include qualifying one-story detached accessory structures no larger than 120 square feet and agricultural or nursery shade-cloth structures without service systems1516. Owner-builders can pull permits, but must provide the required declarations and remain legally and financially responsible for the work17.

Who issues Contra Costa County building permits, and how do you reach them?

The Contra Costa County Department of Conservation and Development handles building permits and planning applications for unincorporated property from its permit center at 30 Muir Road in Martinez1819. Call the Application and Permit Center at 925-655-2700 for building questions or the Planning Division at 925-655-2774 for zoning and land-use questions1819. Applications and plans must be filed digitally through ePermits; paper submittals are no longer accepted5. Building permit fees are based on project valuation, while planning applications require a deposit with time-and-materials billing above it; both are listed in the Land Development Fee Schedule20. Permitted projects are inspected against the approved plans, and the permit and reviewed stamped plans must be onsite for inspection21. Septic and well matters go to Contra Costa Health's Environmental Health Division at 925-608-550022. Richmond issues building permits for ADUs after city Planning approval23. Walnut Creek and Oakley handle their own building permits2425. Septic and well review stays with Contra Costa Health Environmental Health, including city properties6.

Does Contra Costa County have zoning?

Contra Costa County zoning applies to unincorporated land; city parcels follow municipal zoning instead7. Concord, Antioch, Richmond, Pittsburg, Walnut Creek, Brentwood administer their own zoning.262728293031 Oakley, Town of Danville, Martinez, Pleasant Hill, San Pablo, Hercules also administer their own zoning.323334353637 Richmond adopts zoning and subdivision regulations, while Concord Planning provides parcel zoning, permitted-use and development-standard information3839. Septic and well review remains with Contra Costa Health Environmental Health across city boundaries6. For an unincorporated parcel, ask county Planning to identify the district and applicable development plan before choosing a home site419.

What lot sizes and setbacks apply in unincorporated Contra Costa County?

Contra Costa County agricultural standards distinguish lot dimensions from acreage per residential unit: the agricultural land-use matrix specifies at least 40 acres per unit on non-prime agricultural land and 10 acres per unit on agricultural land40. The same matrix lists minimum lot areas of 40 acres in A-40 and 80 acres in A-8040. The A-2 General Agricultural District separately requires at least 5 acres, 250 feet average width and 200 feet depth, subject to its stated exception; meeting these dimensions alone does not resolve residential density4140. Ask county Planning which acreage category and exceptions apply before relying on an agricultural parcel for a home or split; Current Planning reviews unincorporated subdivision applications under local and relevant state regulations and CEQA1942. Montalvin Manor P-1 lot area, coverage and height standards vary by table, and Discovery Bay P-1 setbacks are plan-specific43444546. Qualifying urban housing developments have a separate 4-foot side and rear setback rule47. We could not confirm a general minimum dwelling size; ask the Planning Division for parcel standards19.

How do septic permits work in Contra Costa County?

Contra Costa Health Environmental Health reviews septic and well properties throughout the county, including cities6. Properties with septic systems and no public sewer need approved plans before building-permit application submittal; additions on septic properties also require prior Environmental Health approval48. Contra Costa Health requires a construction permit for new, replacement, altered or abandoned onsite wastewater systems, including conventional and alternative systems, vault privies and sewage holding tanks8. Permitted work requires inspections, final approval and written authorization before the system is changed from the approved plans or placed in service9. Vault privies and sewage holding tanks are permit categories, not permit-free sanitation options49. Only 0.5% of Contra Costa County's mapped soils are rated free of severe limitations for a conventional septic drain field, so evaluate the site and soil before relying on a standard system14. Call Environmental Health at 925-608-5500 about the parcel and application22.

Can you live in an RV or tiny home in Contra Costa County?

Sleeping or living in an RV or travel trailer is prohibited in unincorporated Contra Costa County unless a specific code exception applies; residential storage requires screening from public view and does not authorize occupancy10. Exceptions include lawful mobile-home or travel-trailer parks and land-use-permitted RV parks or campgrounds in designated districts50. Separate mobile-home provisions allow qualifying hardship family occupancy by land-use permit, approved construction-office or watchman use, and approved interim agricultural use; these are conditional uses, not blanket permission to live onsite while building50. Ask the Planning Division which exception, if any, fits the proposed vehicle and use19. Contra Costa County treats a tiny home on wheels as an RV, does not recognize tiny homes as a separate planning category, and prohibits permanently using that vehicle as a mobile home11. A permanent small-home option is an ADU: county Planning approval precedes the building application, with Environmental Health review on septic properties51. A detached ADU up to 800 square feet and 16 feet tall receives streamlined processing without required parking; ADUs may not be permitted for short-term rentals52. We could not confirm a complete private-land temporary-camping rule; ask the Planning Division before staying onsite19.

What are the steps to build a home in Contra Costa County?

  1. Confirm that the parcel is unincorporated, then ask the Planning Division for its zoning district, allowed residential use, setbacks and any special-plan standards719.
  2. Determine water and wastewater service; septic properties without public sewer, including additions on septic properties, need Environmental Health plan approval before the building application48.
  3. If septic is needed, obtain the onsite-wastewater construction permit and plan for required inspections before putting the system into service89.
  4. Check flood and drainage constraints; improvements in a FEMA Special Flood Hazard Area require a Public Works floodplain permit53.
  5. Resolve legal road access and ask Public Works whether driveway work needs an encroachment permit54. A connection within a state-highway right of way requires a Caltrans encroachment permit55.
  6. Submit the application and plans through ePermits; an owner-builder must also submit the required declarations and ownership documentation556.
  7. Keep the permit and stamped plans onsite for required inspections, then complete the applicable final-inspection and occupancy process2157.

What should you check before buying land in Contra Costa County?

Start with jurisdiction and zoning: county zoning information covers unincorporated areas only, while a city parcel follows that city's rules7. Check septic feasibility early because only 0.5% of mapped county soils are rated free of severe limitations for a conventional drain field14. Review slope as well: 48.5% of county land is at a slope of 15% or less, so many parcels may bring grading or access complications58. Confirm whether the building area lies in a FEMA Special Flood Hazard Area, because covered improvements need a floodplain permit and new or substantial improvements require an elevation certificate53. If rental income matters, unincorporated short-term rentals require a permit and are restricted by zoning, hosting arrangement and operating standards59. Ask the water provider whether service is available; if a well is needed, budget for the county permit and inspections13. Finally, budget for property taxes: the effective rate is about 0.8%, and the median annual bill is about $6,9036061.

Watch-outs

  • Sleeping in an RV or travel trailer is prohibited in unincorporated Contra Costa County unless a specific code exception applies50.
  • Only 0.5% of Contra Costa County's mapped soil is rated free of severe limitations for a conventional septic drain field, so verify a usable wastewater site before buying14.
  • Construction in a FEMA Special Flood Hazard Area requires a floodplain permit, and new or substantial improvements also require an elevation certificate53.

Sources

  1. Building Permit Processing FAQ, quoted and re-checked
  2. Planning and Zoning, quoted and re-checked
  3. Current Building Codes, Ordinances & Technical Guidelines for Building Design, quoted and re-checked
  4. Planning and Zoning, quoted and re-checked
  5. Building permit Applications, quoted and re-checked
  6. contracosta.ca.gov, quoted and re-checked
  7. Planning and Zoning, quoted and re-checked
  8. OWTS Construction Permit Application, quoted and re-checked
  9. OWTS Construction Permit Application, quoted and re-checked
  10. Code Enforcement, quoted and re-checked
  11. TINY HOMES, quoted and re-checked
  12. Owner-Builder Acknowledgement and Verification of Information, quoted and re-checked
  13. Water Well Permit Application, quoted and re-checked
  14. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  15. Contra Costa County Frequently Asked Questions, quoted and re-checked
  16. Construction Work Not Requiring a Building Permit, quoted and re-checked
  17. Building Permit Processing FAQ, quoted and re-checked
  18. Contra Costa County Department of Conservation and Development - Building Inspection (contracosta.ca.gov)
  19. Contra Costa County Department of Conservation and Development - Planning Division (contracosta.ca.gov)
  20. contracosta.ca.gov, quoted and re-checked
  21. Building permit Applications, quoted and re-checked
  22. Contra Costa Health - Environmental Health Division (cchealth.org)
  23. Richmond: Accessory Dwelling Units (ADUs) (Contra Costa County), quoted and re-checked
  24. Walnut Creek: Article 3: Permits and Inspections (Contra Costa County), quoted and re-checked
  25. Oakley: Building (Contra Costa County), quoted and re-checked
  26. Concord: Land Use & Zoning Information (Contra Costa County), quoted and re-checked
  27. Antioch: official source (Contra Costa County), quoted and re-checked
  28. Richmond: Zoning & Subdivision Regulations (Contra Costa County), quoted and re-checked
  29. Pittsburg: Title 18 Zoning (Contra Costa County), quoted and re-checked
  30. Walnut Creek: CHAPTER 10-2: Zoning (Contra Costa County), quoted and re-checked
  31. Brentwood: City of Brentwood, CA Code of Ordinances (Contra Costa County), quoted and re-checked
  32. Oakley: City of Oakley Municipal Code (Contra Costa County), quoted and re-checked
  33. Town of Danville: Zoning Ordinance & Map (Contra Costa County), quoted and re-checked
  34. Martinez: Title 22: Zoning - City of Martinez, CA (Contra Costa County), quoted and re-checked
  35. Pleasant Hill: Table of Contents - City of Pleasant Hill, CA (Contra Costa County), quoted and re-checked
  36. San Pablo: Chapter 17.01 Title and Purpose (Contra Costa County), quoted and re-checked
  37. Hercules: City of Hercules Municipal Code (Contra Costa County), quoted and re-checked
  38. Zoning & Subdivision Regulations, quoted and re-checked
  39. Land Use & Zoning Information, quoted and re-checked
  40. Land Use Matrix for Agricultural Zoning Districts, quoted and re-checked
  41. Chapter 84-38 - A-2 General Agricultural District, quoted and re-checked
  42. Planning and Zoning, quoted and re-checked
  43. Montalvin Manor P-1 Development Guidelines, quoted and re-checked
  44. Montalvin Manor P-1 Development Guidelines, quoted and re-checked
  45. Montalvin Manor P-1 Development Guidelines, quoted and re-checked
  46. Development Plan Minor Modification for New Single-Family Residence in Discovery Bay, County File DP18-3010, quoted and re-checked
  47. Zoning Code and Area Wide Planned Unit Development Plans, quoted and re-checked
  48. contracosta.ca.gov, quoted and re-checked
  49. OWTS Construction Permit Application, quoted and re-checked
  50. Contra Costa County Ordinance Code, Chapter 84-68, T-1 Mobile Home/Manufactured Home Park District, quoted and re-checked
  51. Accessory Dwelling Units, quoted and re-checked
  52. Accessory Dwelling Units, quoted and re-checked
  53. FEMA Floodplain Management Program, quoted and re-checked
  54. Contra Costa County Public Works Department - Encroachment Permits (contracosta.ca.gov)
  55. Encroachment Permits | Caltrans (California statewide rule), quoted and re-checked
  56. contracosta.ca.gov, quoted and re-checked
  57. Permits by Department, quoted and re-checked
  58. Share of land at 15% slope or less: Bolthole Index county data
  59. Short-Term Rentals, quoted and re-checked
  60. Effective property tax rate: Bolthole Index county data
  61. Median property tax bill: Bolthole Index county data

Written October 11, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

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Compared with neighboring counties

Like all 6 of its neighbors, Contra Costa County has countywide zoning.

RuleContra Costa CountyAlameda CountySolano CountySan Francisco CountySan Joaquin CountySan Mateo CountyNapa County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredLimited
County zoningYesYesYesYesYesYesYes
Septic permitsContra Costa HealthCounty Dept. of Env. HealthCounty Env. Health Div.Not publishedCounty Env. Health Dept.County Env. Health ServicesCounty Env. Health Div.

County locator

Contra Costa County in California

27
County map
Contra Costa County highlighted among the California counties · colored by Index score

How Contra Costa County scores

Seclusion9100% ev.
Self-Sufficiency4696% ev.
Admin Boringness41100% ev.
Durability30100% ev.
Property Autonomy56100% ev.
Carry Cost51100% ev.

Evidence strength: 99%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$787kTypical home
0.8%Property tax
$9,199Land / acre
19.3"Annual rain
40.4% of yrsSevere drought
13.2 / yr (+8.4)Mid-century 100°F days
97.4 daysMid-century dry spell
1.51" (+7.9%)Mid-century 1-day rain
1.07×Wildfire change factor
100%Forward climate coverage
$1,682Home insurance / yr
5.7% / yrInsurance growth
0.73%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
599,339People within 30 min
12,666,427People within 2 hr
815,147Radius comparison (15 mi)
1,611.1People / sq mi
2.1%Federal land
48.5%Land at 15% slope or less
0.5%Soils rated "not limited" for septic (strict USDA rating)
1,718 acWorkable land screen
45.3 tonsBiomass / forest ac
60.4°FAvg temp

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Cities and towns in Contra Costa County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Town of Moraga · San Ramon

Answers from the rulebook for Contra Costa County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Contra Costa County rules

  • Building permitRequired

    Structural, plumbing, mechanical, or electrical work in unincorporated Contra Costa County.

    • A permit is required whenever structural, plumbing, mechanical, or electrical work is performed.
    • One-story detached accessory buildings used as tool or storage sheds, playhouses, and similar uses are exempt when the floor area does not exceed 120 square feet.
    • Unless specifically exempt, anything else needs permits.
    • If electricity or water is brought to an otherwise exempt structure, permits are required; electrical, plumbing, and mechanical permits are required for a structure that may not require a building permit.
    • The cited county FAQ does not establish applicability inside incorporated municipalities.

    maximum floor area for specified detached accessory exemption: <= 120 square feet (One-story detached accessory buildings used as tool and storage sheds, playhouses, and similar uses.)

    “A permit is required whenever any structural, plumbing, mechanical or electrical work is to be performed. If you are unsure please feel free to contact us for help at 925-655-2700.”
    One more reviewed finding on this topic
    • Required — Building construction and related work under Contra Costa County building-permit jurisdiction, particularly unincorporated areas.
      “Almost all projects require permits. These include, but are not limited to, new structures, demolitions, additions, alterations, interior/exterior remodels, running new electrical, water or gas lines, repairs, outdoor kitchens, pergolas, pavilions, decks, carports, garages, docks, pools, foundation repairs, ADUs, and Junior ADUs, solar, energy storage systems, and backup generators.”
  • Owner-builder exemptionConditional

    Property owners seeking to obtain a Contra Costa County building permit as owner-builders.

    • Owner-builders, including trusts or corporations, may pull permits.
    • Proof of ownership may be required.
    • The Building Permit Declaration form is required.
    • Before permit issuance, the property owner must complete and submit the Owner-Builder Acknowledgement and Verification form; an agent may not execute it.
    • The owner-builder is the responsible party of record and legally and financially responsible for the proposed construction.
    • If the owner employs persons other than California licensed contractors and construction value is at least $500 including labor and materials, the owner may be considered an employer.
    • An owner-builder building single-family residential structures cannot legally build them with intent to offer them for sale unless all work is performed by licensed subcontractors and the number of structures does not exceed four within a calendar year, or all work is performed under contract with a licensed general building contractor.
    • This is an owner-builder permit pathway, not an exemption from obtaining a building permit.

    construction value threshold for possible employer status: >= 500 USD (including labor and materials)

    “We will not issue a building permit until you have read, initialed your understanding of each provision, signed, and returned this form to us at our official address:”
    2 more reviewed findings on this topic
    • Available (with conditions) — An owner-builder applying for a County building permit for property improvements in the County building-permit service area.
      “We will not issue a building permit until you have read, initialed your understanding of each provision, signed, and returned this form to us”
    • Available (with conditions) — A property owner applying for a building permit for work on the owner's property in unincorporated Contra Costa County.
      “An Owner-Builder is the property owner who is submitting applications for permits on their own property.”
  • Building code adoptedAdopted (with conditions)

    Building construction in unincorporated Contra Costa County subject to the County Building Inspection Division's listed codes and ordinances.

    • The listed current codes include the 2025 California Building Standards Administrative Code Part 1, 2025 California Building Code Parts 2 Volumes 1 and 2, 2025 California Residential Code Part 2.5, California Electrical, Mechanical, Plumbing, Energy, Wildland-Urban Interface, Historical, Fire, Existing Building, Green Building, and Reference Standards Codes.
    • Contra Costa County Code Title VII also applies.
    • City ordinances apply depending on the city where the property is located, so incorporated-city requirements are not treated as County-only rules.
    • The source document states 'Updated 01/02/2026'; this is treated as a document update date, not as an effective or adoption date.
    “Current Building Codes & Ordinances • 2025 California Building Standards Administrative Code Part 1”
  • InspectionsRequired

    Building projects requiring a Contra Costa County building permit in unincorporated areas.

    • Building inspections ensure the built project meets the permitted plans.
    • Inspections are scheduled by phone at 925-646-4108 or through the ePermits Center.
    • For a scheduled inspection, the building permit and reviewed and stamped building plans must be onsite.
    • An adult representative age 18 or older must be onsite; the work must be ready; prior deficiencies must be corrected; and the inspector must have access to the work.
    • Some project plans may require special inspection by recognized inspection and testing agencies.
    • The county inspection page states that failure to meet the day-of-inspection requirements may result in cancellation and a re-inspection fee.

    inspection appointment window: 3-hour windows

    “This permit will expire 365 days from the date of issue without approval of a required inspection or if 180 days lapse between approved required inspections.”
  • Certificate of occupancyLimited

    County-administered multifamily housing rehabilitation projects covered by the Contra Costa County Multi-Family Housing Rehabilitation Standards.

    • The source applies to properties assisted through Contra Costa County's Multi-family Housing Program.
    • The occupancy certificate is required only when required by the applicable project or building requirements.
    • Final disbursement is withheld until cited deficiencies and lead-based paint hazards are corrected and, when required, the building inspector has issued an occupancy certificate.
    • The standards incorporate the current edition of the International Building Code as adopted by Contra Costa County, with the more stringent standard applying where there is a conflict.
    “when required, the building inspector has issued an occupancy certificate.”
    One more reviewed finding on this topic
    • Limited — County building-permit projects requiring a final inspection and certificate-of-occupancy process.
      “Final Inspection (Certificate of Occupancy)”
  • County-wide zoningPresent (with conditions)

    Land-use entitlement and zoning review for proposed development on properties in unincorporated Contra Costa County.

    • The County Current Planning division reviews rezoning, subdivision, land-use, development-plan, tree-permit, and variance applications.
    • Applications must conform to local and relevant state regulations and CEQA.
    • The source identifies the scope as properties located within unincorporated Contra Costa County.
    “The division is also responsible for updating the County's zoning code.”
  • Local zoningVaries (with conditions)

    Aggregate conclusion for local zoning across Contra Costa County: County zoning applies in unincorporated areas, while incorporated municipalities administer their own zoning regulations.

    • The County source expressly limits County zoning information and Current Planning jurisdiction to unincorporated areas.
    • Municipal zoning is administered by the relevant city rather than by Contra Costa County.
    • A parcel-specific determination requires identifying whether the property is in an unincorporated area or an incorporated municipality and then consulting the applicable zoning district and standards.
    “Note the general plan and zoning information is available for unincorporated County areas only.”
  • Zoning districtsPublished (with conditions)

    County zoning districts and area-wide planned unit development codes in unincorporated Contra Costa County.

    • County zoning information is available for unincorporated County areas only.
    • The County provides a zoning code, area-wide P-1 zoning codes, a zoning map through CCMAP, and specific plans.
    • The listed unincorporated areas with P-1 zoning codes are Bay Point, Contra Costa Centre, El Sobrante, Montalvin Manor, North Richmond, and Rodeo.
    • The listed areas with specific plans are Alhambra Valley, Dougherty Valley (San Ramon), El Sobrante, Contra Costa Centre, Montalvin Manor, North Gate, North Richmond, Pittsburg/Bay Point BART Station Area, Rodeo, and Shell Ridge.
    • Incorporated cities administer their own zoning rules; this claim does not assign municipal zoning to the County.
    “Zoning Code - Including Area-Wide Planned Unit Developments (P-1). [...] Note the general plan and zoning information is available for unincorporated County areas only.”
  • Minimum lot sizeSpecified

    Residential structures in the agricultural zoning districts covered by the County agricultural land-use matrix.

    • The source distinguishes non-prime agricultural land from agricultural land.
    • The standards are stated per residential unit.
    • A-40 and A-80 districts have additional district-specific minimum lot-area rules.

    minimum area per unit on non-prime agricultural land: >= 40 acres · minimum area per unit on agricultural land: >= 10 acres · A-40 minimum lot area: >= 40 acres (Applies to any building or other structure permitted in an A-40 district) · A-80 minimum lot area: >= 80 acres (The source footnote labels this as an A-80 district rule)

    “less than forty acres per unit for non‐prime agricultural land, or less than ten acres per unit [...] A‐40 district [...] forty acres [...] A‐80 district [...] eighty acres”
    2 more reviewed findings on this topic
    • District specific (with conditions) — Minimum lot area in the unincorporated Montalvin Manor P-1 development-standard districts shown in the County guideline table.
      “Minimum Lot Area 3,500 sq. ft 6,000 sq. ft-7,000 sq. ft 3,500 sq. ft. 5,000 sq. ft. 2,500 sq. ft N/A N/A”
    • Specified — Uses allowable under Article 84-38.4 in the County A-2 General Agricultural District in unincorporated Contra Costa County.
      “five acres in area, two hundred fifty feet average width, and two hundred foot depth.”
  • SetbacksDistrict specific (with conditions)

    Residential units in qualifying urban housing developments located in single-family residential zones in unincorporated Contra Costa County.

    • The rule applies to an urban housing development regulated under County Code Chapter 88-36.
    • Side and rear yards of four feet are allowed for a residential unit in an urban housing development.
    • There are no setback or yard requirements for an existing residential unit, or for a new residential unit constructed in the same location and to the same dimensions as an existing residential unit.
    • The County Planning Commission report describes the urban housing development as consisting of up to two residential units on a qualifying parcel in a single-family residential zone.
    • The County's Planning and Zoning page states that its zoning information and zoning code administration apply to unincorporated County areas.

    side yard setback: 4 feet (Urban housing development) · rear yard setback: 4 feet (Urban housing development)

    “A setback is not required for an existing residential unit or a residential unit constructed in the same location and to the same dimensions as an existing building. [...] A setback of four feet from the side and rear lot lines is required for a residential unit that is not an existing residential unit or is not constructed in the same location and to the same dimensions as an existing building.”
    One more reviewed finding on this topic
  • Lot coverageDistrict specific (with conditions)

    Maximum lot coverage in the unincorporated Montalvin Manor P-1 development-standard districts shown in the County guideline table.

    • The table contains multiple land-use/zoning columns; the applicable maximum depends on the specific district/use column.
    • The source does not establish a single countywide lot-coverage limit.

    maximum lot coverage: 35%; 35%; ---; 50%; ---; 50%; 40% percent (varies by table column)

    “Maximum Lot Coverage 35% 35% --- 50% --- 50% 40%”
  • Building heightDistrict specific (with conditions)

    Maximum building height in the unincorporated Montalvin Manor P-1 development-standard districts shown in the County guideline table.

    • The table contains multiple land-use/zoning columns; the applicable maximum depends on the specific district/use column.
    • Where the area abuts a single-family residential district, the portion of the district within 50 feet of that district has a 20-foot maximum.
    • Detached accessory structures covered by the source note may be no higher than 15 feet.

    maximum building height: 50 ft.; 30 ft.; 50 ft.; 35 ft. or 2 1/2 stories; 20 ft.; 35 ft.; 35 ft. feet/stories (varies by table column) · abutting single-family district height limit: 20 feet (portion within 50 feet of the abutting single-family residential district)

    “Maximum Building Height 50 ft. 30 ft.(b) 50 ft. 35 ft. or 2 1/2 stories 20 ft. 35 ft. 35 ft.”
  • Living in an RVLimited

    Human habitation, including sleeping, in a mobile home, recreational vehicle, or travel trailer within unincorporated Contra Costa County land use districts regulated by the County Ordinance Code.

    • The general rule prohibits locating, maintaining, or using a mobile home, recreational vehicle, or travel trailer for human habitation, including sleeping, in any land use district.
    • An exception applies when the use is authorized by Article 84-68.16, 84-68.18, or 84-68.20.
    • An exception applies when the vehicle is located in a lawful mobile home park or lawful travel trailer park.
    • An exception applies when the vehicle is located in a lawful recreational vehicle park or campground allowed by a land use permit, but only in A-2, A-3, RB, C, L-1, and T-1 districts.
    • Article 84-68.16 permits qualifying permanent mobile-home habitation by building permit in single-family residential and agricultural districts, subject to the article's development, foundation, certification, exterior-material, and zoning-administrator requirements.
    • Article 84-68.18 permits qualifying caretaker mobile-home habitation in specified districts when the zoning administrator finds that the article's criteria and procedures are satisfied; the initial land-use permit may not exceed four years and extensions may not exceed four years.
    • Article 84-68.20 provides temporary-use exceptions, including family occupancy by land-use permit upon hardship involving age or health, construction-office or watchman use approved by the zoning administrator after building-inspection and health-department permits, and interim agricultural use by approved land-use permit for no more than five years on an agricultural parcel of at least ten acres.
    • Section 84-68.1404 separately allows storage at a residence only when the vehicle is not used for living or sleeping and is adequately screened from public roadways or thoroughfares.
    • Incorporated municipalities may apply their own land-use regulations; this claim is limited to the County's unincorporated jurisdiction.

    recreational vehicle park or campground minimum area: >= 1 acre (The code defines such a park or campground as an area of at least one acre with provisions for temporary occupancy, including sleeping, for recreational or travel purposes.) · interim agricultural mobile-home permit maximum term: <= 5 years (No permit extensions are allowed under Section 84-68.2006.)

    “No mobile home, recreational vehicle, or travel trailer shall be located, maintained or used for human habitation, including sleeping, in any land use district, except as follows: (a) The use of the mobile home, recreational vehicle, or travel trailer is authorized by Article 84-68.16, 84-68.18, or 84-68.20. (b) The mobile home, recreational vehicle, or travel trailer is located in a lawful mobile home park or travel trailer park. (c) The mobile home, recreational vehicle, or travel trailer is located in a lawful recreational vehicle park or campground allowed by a land use permit in these districts only: A-2, A-3, RB, C, L-1 and T-1.”
    One more reviewed finding on this topic
    • Limited — Human habitation, including sleeping, in a recreational vehicle or travel trailer in unincorporated Contra Costa County.
      “No mobile home, recreational vehicle, or travel trailer shall be located, maintained or used for human habitation, including sleeping, in any land use district, except as follows:”
  • Tiny homesLimited

    Tiny-home occupancy in unincorporated Contra Costa County.

    • Contra Costa County has no planning regulation recognizing Tiny Homes.
    • Tiny homes on wheels are treated as recreational vehicles and may not be permanently used as mobile homes.
    • An accessory dwelling unit pathway requires a permanent foundation and a property with an existing primary residence.
    • Mobile homes must comply with County Code Section 84-68.20 for temporary use; permanent mobile homes on an undeveloped lot are directed to County Code Section 84-68.16.
    “Contra Costa County has no planning regulation recognizing “Tiny Homes”.”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units in unincorporated Contra Costa County.

    • ADUs require both planning and building approvals.
    • Applicants must obtain Planning approval before submitting a Building Permit application.
    • Completed ADU planning and building checklists are required.
    • If the property has a septic system, plans must be reviewed by Environmental Health.
    • ADUs are not allowed to be permitted for short-term rental use.
    • Junior ADUs have a maximum size of 500 square feet and are only allowed in single-family residential districts.
    • A detached ADU up to 800 square feet and up to 16 feet in height has streamlined processing and is not subject to parking requirements.
    • The County provides building-permitting services for Clayton, Hercules, Lafayette, Orinda, and Moraga, but those cities require city planning approval before County building-permit submission.

    junior ADU maximum size: <= 500 square feet · streamlined detached ADU maximum size: <= 800 square feet · streamlined detached ADU maximum height: <= 16 feet

    “ADUs require both planning and building approvals. The process is the same if the applicant is legalizing an existing ADU or constructing a new ADU.”
    One more reviewed finding on this topic
    • Allowed (with conditions) — Accessory dwelling units in unincorporated Contra Costa County.
      “ADUs require both planning and building approvals.”
  • Who permits septicCounty

    Properties with septic systems in Contra Costa County.

    • Environmental Health approved plans are required at application submittal for projects involving septic systems.
    • Sanitary or sanitation district approval may also be required where public sewer service is involved.
    “Contra Costa County Environmental Health [...] Serves properties with septic systems and wells. Projects with septic systems or wells require Environmental Health approved plans at application submittal.”
  • Septic permitRequired

    Construction, alteration, replacement, abandonment, tank replacement, vault privy, and sewage holding tank work involving onsite wastewater treatment systems.

    • The official application identifies new conventional, new alternative, alteration, replacement, septic abandonment, tank replacement, vault privy, and sewage holding tank permit work types.
    • The application itself is not the permit.
    • Approved permit conditions and plans must be followed; written authorization is required before deviation or placing the system in service.
    “ONSITE WASTEWATER TREATMENT SYSTEM (OWTS) CONSTRUCTION PERMIT APPLICATION [...] New Conventional Construction Permit (12) [...] New Alternative Construction Permit (15) [...] OWTS Alteration Permit (Limited) (19) [...] Alternative Replacement Construction Permit (20) [...] Conventional Replacement Construction Permit (14) [...] Septic Abandonment (21) [...] Tank Replacement (includes Abandonment) (25) [...] Vault Privy (53) [...] Sewage Holding Tank (18)”
  • Septic inspectionRequired

    Permitted onsite wastewater treatment system construction and related work.

    • The permit applicant agrees to obtain all required inspections.
    • The approved permit and plans must remain at the job site until final approval.
    • Written authorization is required before deviating from approved permit or plans or placing the system in service.
    “I agree to obtain all required inspections, maintain a copy of the approved permit and plans at the job site until final approval, and obtain written authorization prior to deviating from the approved permit or plans, or placing the system in service.”
  • Off-grid sanitationLimited

    Off-grid sanitation forms specifically identified by the County Environmental Health OWTS application, including vault privies and sewage holding tanks.

    • The official OWTS application lists Vault Privy and Sewage Holding Tank as permit work types.
    • The application states that it is not itself the permit.
    • Approved permit conditions and applicable laws and regulations apply.
    • Required inspections must be obtained, and written authorization is required before deviations from approved plans or placing the system in service.
    “Vault Privy (53) Sewage Holding Tank (18)”
    One more reviewed finding on this topic
    • Limited — Use of onsite wastewater/septic systems on properties not served by public sewer.
      “Properties with septic systems which are not served by a public sewer need plans approved by Contra Costa Environmental Health prior to building permit application submittal. Additions on properties that contain a septic system must have plans reviewed and approved by Contra Costa Environmental Health prior to building permit application submittal.”
  • Well permitRequired

    Domestic, industrial, agricultural/irrigation, public/small-water-system, reconstruction, flow-test, and destruction water-well work in Contra Costa County.

    • One application is required per well.
    • The application fee is non-refundable and service fees are additional according to the fee schedule.
    • A plot plan must be attached.
    • A variance is required for water-well annular seals less than 50 feet.
    • The application must be signed by a C-57 licensed driller.
    • Required inspections must be obtained and written authorization is required before deviation from approved permit conditions or placing the well in service.

    water-well annular-seal variance threshold: < 50 feet (A variance is required for water-well annular seals less than 50 feet.)

    “WATER WELL PERMIT APPLICATION [...] ONE APPLICATION PER WELL [...] Domestic Water Well (69) [...] Industrial Well (73) [...] Agricultural/Irrigation Well (72) [...] Well Reconstruction (69) [...] Public/Small Water System Well (63) [...] Flow Test (99) [...] Well Destruction (68)”
  • Agricultural exemptionAvailable (with conditions)

    County business-license exemption for businesses engaged in growing livestock, poultry, or agricultural products for sale or disposal by the growers themselves.

    • The exemption is under the County Business License Ordinance and is not a blanket exemption from zoning, subdivision, building-permit, septic, or other land-use requirements.
    • The applicant must submit proof of exempt status with the application or renewal notice, such as state or federal certification or other documents if applicable.
    • Failure to submit proof may cause the County to deny or delay processing.
    “Businesses engaged in growing livestock, poultry or agricultural products for sale or disposal by the growers themselves. (Ordinance 91-35 Section 1).”
    One more reviewed finding on this topic
    • Available (with conditions) — Building-permit exemption for shade-cloth structures constructed for nursery or agricultural purposes in Contra Costa County.
      “Shade cloth structures constructed for nursery or agricultural purposes, not including service systems.”
  • Subdividing landRegulated (with conditions)

    Subdivision and related land-use entitlement applications for proposed development on properties in unincorporated Contra Costa County.

    • Applications are processed in conformance with local and relevant state regulations.
    • The California Environmental Quality Act (CEQA) applies where relevant.
    • The source describes review and processing of applications; it does not provide a complete subdivision-fee or map-approval schedule.
    “The Current Planning division is responsible for the review and processing of land use entitlements such as rezoning, subdivision, land use, development plan, tree permit, and variance applications in conformance with local, relevant state regulations, and the California Environmental Quality Act (CEQA) for proposed development on properties located within unincorporated Contra Costa County.”
    One more reviewed finding on this topic
    • Regulated (with conditions) — Subdivision applications for properties located within unincorporated Contra Costa County.
      “review and processing of land use entitlements such as rezoning, subdivision [...] for proposed development on properties located within unincorporated Contra Costa County.”
  • Building in a floodplainRequired

    Construction of improvements within a FEMA-designated Special Flood Hazard Area in unincorporated Contra Costa County.

    • A Floodplain Permit is required for improvements within the SFHA.
    • An Elevation Certificate is required for new and substantial improvements.
    • The County states that the lowest floor, including basement, for all new structures or substantial improvements within an SFHA must be elevated one to two feet above the 100-year Base Flood Elevation.
    • The program is for unincorporated County areas only.
    • The written flood-zone determination fee is $100 per parcel; if a site visit is warranted, an additional $400 plus time and material fee applies.

    lowest-floor elevation above 100-year BFE: 1 to 2 feet · written flood-zone determination: 100 USD per parcel · site-visit surcharge: >= 400 USD plus time and material fee (applies if a site visit is warranted)

    “If you are constructing improvements within the SFHA, you are required to apply for a Floodplain Permit (PDF) from the Public Works Department”
  • Short-term rentalsLimited

    Short-term rentals in unincorporated Contra Costa County.

    • An STR may operate only after issuance of an STR permit; the permit is ministerial if all requirements are met.
    • Eligible property must be in unincorporated Contra Costa County and in a single-family, residential planned-unit, multifamily residential, or agricultural district not subject to a Williamson Act contract.
    • A land use permit is required to deviate from the standards.
    • Non-hosted STRs are limited to 90 rental days per calendar year; hosted STRs are limited to 180 days.
    • No more than one STR may operate on a lot.
    • A dwelling unit in a building containing five or more dwelling units may not operate as an STR.
    • Guest occupancy is limited to two persons per bedroom plus two additional persons, excluding children under 12.
    • Accessory dwelling units, events, excessive traffic/noise, road obstruction, and signage are prohibited; no more than 20 total persons may gather.
    • A business license and valid transient occupancy registration certificate are required before renting.
    • The permit expires one year after approval unless revoked sooner; renewal must be filed at least 30 calendar days before expiration.
    • Owners within 300 feet are noticed after permit issuance.

    non-hosted rental days: <= 90 days per calendar year · hosted rental days: <= 180 days per calendar year · notice radius: 300 feet · maximum STRs per lot: <= 1 STR · maximum occupancy: two persons per bedroom plus two additional persons persons (children under age 12 are not counted)

    “A non-hosted short-term rental may not be rented for more than 90 days in any calendar year.”
  • Permit feesVariable (with conditions)

    County-administered building and planning permits in unincorporated Contra Costa County.

    • Planning fees require a minimum application-based deposit and time-and-materials charges; the applicant is billed for any amount exceeding the deposit.
    • Building permit fees are based on project valuation.
    • Fees are outlined in the Land Development Fee Schedule.
    • The source states that new land development fees were adopted December 17, 2019 and implemented March 1, 2020.
    “Planning Fees require a minimum deposit based on the application. [...] Building Permit Fees are based on the valuation of the project.”
  • Permit processPublished (with conditions)

    Standard building permit applications administered by Contra Costa County in unincorporated areas.

    • The standard building permit submittal process is used for staff to determine required permits.
    • Larger projects require a plan check fee at the beginning of plan check; plan review begins after payment is confirmed.
    • Applications and plans must be submitted digitally through the ePermits Center; paper applications and plans are no longer accepted.
    “All Building Permit Applications are submitted through our ePermits System. The following resources can guide Applicants through the process.”

California rules that apply here

  • Minimum dwelling sizeSpecified

    Efficiency units permitted by a California city, county, or city and county.

    • The local jurisdiction must adopt an ordinance permitting the efficiency unit.
    • Occupancy is limited to no more than two persons.
    • The unit may have partial kitchen or bathroom facilities as specified by the local ordinance.
    • All other applicable minimum standards under Health and Safety Code Part 1.5 continue to apply.

    minimum floor area: >= 150 square feet · maximum occupancy: <= 2 persons

    “Notwithstanding Sections 17922, 17958, and 17958.5, a city, county, or city and county may, by ordinance, permit efficiency units for occupancy by no more than two persons which have a minimum floor area of 150 square feet and which may also have partial kitchen or bathroom facilities, as specified by the ordinance.”
  • Camping on your landLimited

    Camping in units operated by the California Department of Parks and Recreation statewide.

    • Camping is confined to areas designated for that purpose.
    • Occupancy by the same persons, equipment, or vehicles is generally limited to 30 days in any calendar year in that unit.
    • The Department may establish shorter or longer occupancy limits.
    • When a shorter seasonal limit applies, the camper must vacate the campsite and may not reregister in the unit until 48 hours have expired, measured from 12:00 noon on the checkout day to 12:00 noon on the second day following.
    • A district superintendent may permit one-night camping in a day-use area or portion of one, subject to Department-established fees and vehicle limitations; occupants must vacate by 9:00 a.m. the following morning.
    • California State Parks' current reservation policy states that each campground has a consecutive-night limit, requires a 48-hour absence after that limit, and generally has a 30-night annual maximum, subject to individual park policies.

    general annual occupancy limit: 30 days per calendar year per unit (The Department may establish shorter or longer limits of occupancy.) · return interval after shorter seasonal limit: 48 hours (Measured from 12:00 noon of the checkout day to 12:00 noon of the second day following.) · one-night camping in day-use area: 1 night (Only if permitted by the district superintendent; occupants must vacate by 9:00 a.m. the following morning.)

    “Occupancy by the same persons, equipment, or vehicles of any camping facility is limited to a total of 30 days in any calendar year in that unit.”
    One more reviewed finding on this topic
    • Allowed (with conditions) — Temporary camping in California special occupancy parks, including parks containing recreational vehicles, tents, or camping cabins.
      ““Special occupancy park” means a recreational vehicle park, temporary recreational vehicle park, incidental camping area, or tent camp.”
  • Manufactured homesAllowed (with conditions)

    Occupancy of manufactured homes inside or outside mobilehome parks in California.

    • The manufactured home must satisfy applicable federal standards and California Manufactured Housing Act and Title 25 requirements.
    • Installation and approval for occupancy are governed by the Mobilehome Parks Act.
    • HCD or a local enforcement agency with assumed Mobilehome Parks Act authority is responsible for ensuring compliance with statutory construction and maintenance requirements.
    • Local agency approvals may be necessary for the project.

    minimum width for a new manufactured home: >= 8 body feet (The statutory definition also includes units at least 40 body feet in length.) · minimum erected floor area for a new manufactured home: >= 320 square feet

    “MHs may be occupied outside or inside of mobilehome parks and installation and approval for occupancy is governed by the Mobilehome Parks Act (MPA), HSC Sections 18200, et seq., and Title 25, CCR Sections 1000, et seq.”
  • Mandatory utility hookupSewer (with conditions)

    Certain existing OWTS in California Tier 3 impaired-water-body areas that commit to connect to a centralized wastewater collection and treatment system regulated through waste discharge requirements.

    • The OWTS must have been constructed and operating, or permitted, on or before the date the nearby water body was added to OWTS Policy Attachment 2.
    • The owner must commit by legally binding document to connect to a centralized wastewater collection and treatment system regulated through waste discharge requirements.
    • The owner must sign the legally binding document within 48 months after the nearby water body's initial listing on Attachment 2.
    • The specified connection date may not extend beyond nine years after the date the nearby water body is added to Attachment 2.
    • The rule is an exception to Section 10 requirements for qualifying existing or permitted systems; it is not a general statewide requirement that every property connect to public sewer.

    deadline to sign connection commitment: 48 months (Measured from the date the nearby water body is initially listed on Attachment 2.) · maximum time to complete connection: <= 9 years (Measured from the date the nearby water body is added to Attachment 2.)

    “The owner must sign the document within forty-eight months of the date that the nearby water body is initially listed on Attachment 2. The specified date for the connection to the centralized community wastewater collection and treatment system shall not extend beyond nine years following the date that the nearby water body is added to Attachment 2.”
  • Driveway accessRequired

    Driveways and driveway connections involving proposed encroachments within, under, or over State highway rights of way.

    • The requirement applies to proposed activities related to placement of encroachments within, under, or over State highway rights of way.
    • Applications are submitted to the appropriate District Encroachment Permits Office having jurisdictional authority over the site.
    • Local or other agency requirements may also apply outside State highway rights of way.
    “An encroachment permit must be obtained for all proposed activities related to the placement of encroachments within, under, or over the State highway rights of way.”
  • Campground & park staysLimited

    Occupancy and use of manufactured homes and mobilehomes in California mobilehome parks and other locations subject to HCD jurisdiction.

    • HCD administers titling and registration for manufactured homes and mobilehomes.
    • HCD-inspected mobilehome parks are subject to health and safety enforcement where local government has not assumed enforcement.
    • Manufactured/mobilehome park regulations address construction, use, maintenance, and occupancy.
    • Separate local land-use, building, fire, health, and utility requirements may apply.
    “MHs may be occupied outside or inside of mobilehome parks and installation and approval for occupancy is governed by the Mobilehome Parks Act (MPA), HSC Sections 18200, et seq., and Title 25, CCR Sections 1000, et seq.”
    One more reviewed finding on this topic
    • Limited — Occupancy and use of recreational vehicles in California special occupancy parks and designated RV sections of mobilehome parks.
      “Unless otherwise allowed by a local ordinance, RVs generally may be occupied only in mobilehome parks or special occupancy parks governed by the Mobilehome Parks Act”
  • county zoning authorityGeneral

    California county legislative bodies' authority to adopt zoning ordinances regulating buildings, structures, land uses, lots, yards, open space, lot coverage, intensity of use, parking, loading, and setbacks within county jurisdiction, including unincorporated areas.

    • The authority is exercised pursuant to Government Code Chapter 4, Zoning Regulations.
    • The statute separately authorizes city legislative bodies; incorporated municipalities may exercise their own zoning authority.
    • Government Code Section 65850 also lists authority to regulate signs and billboards, building and structure location, height, bulk, number of stories, and size, lot and open-space size and use, lot coverage, intensity of land use, offstreet parking and loading, and building setback lines.
    • The cited section states it was amended by Stats. 2017, Ch. 376, Sec. 1, effective January 1, 2018.
    “The legislative body of any county or city may, pursuant to this chapter, adopt ordinances that do any of the following:”
  • county building authorityGeneral

    California counties administering and enforcing state building standards through county building departments, including residential construction in unincorporated areas.

    • Each county must maintain building standards and state building regulations in the office of the building official responsible for administration and enforcement of state building standards.
    • The statewide Title 24 standards apply subject to statutory exceptions and any authorized local amendments or local requirements.
    • The cited HCD bulletin concerns the 2019 California Building Standards Code and its July 1, 2021 supplement; later code editions may supersede those particular edition dates.
    “These codes shall be maintained in the office of the building official responsible for the administration and enforcement of state building standards”

Inside cities and towns in Contra Costa County

Municipal rules found while researching the county. They apply inside that city or town, not to unincorporated land.

  • Local zoningPresent (with conditions)

    Properties within the City of Concord, Contra Costa County.

    • The Concord Planning Division provides zoning information and development standards.
    • The applicable rules depend on the property's zoning and the City's Development Code.
    “The Planning Division can assist you with information regarding zoning, permitted land uses, and development standards in the City of Concord.”
    One more reviewed finding on this topic
    • Present (with conditions) — Properties within the City of Richmond, Contra Costa County.
      “these regulations are adopted by the Richmond City Council to achieve the following objectives:”

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Water rights & wells in Contra Costa County

Whether a new home can legally get its own water here — the sub-state groundwater regime, from California’s water agency.

Actively managed

This basin is under active state management — new water use is scrutinized, though a domestic well is usually still allowed.

Household wellPermit required — restricted

California requires no STATE permit for a domestic well — wells are permitted by the county — but under SGMA a Groundwater Sustainability Agency can meter or restrict new wells in medium/high-priority and critically overdrafted basins, and Executive Order N-7-22 requires counties in those basins to get GSA verification that a new well is consistent with the Groundwater Sustainability Plan before permitting.

Limit: 2 acre-feet/year de minimis under SGMA (Water Code §10721(e)) — largely exempt from GSA metering/fees

California DWR / State Water Board — SGMA de minimis & EO N-7-22 Action 9 FAQ ↗
  • East Contra Costa Subbasin — Medium Prioritypartial of county

    Medium-priority SGMA basin (DWR 2019 Basin Prioritization) requiring an adopted Groundwater Sustainability Plan; a new well is subject to GSA consistency review under Executive Order N-7-22. De minimis domestic wells (<2 af/yr) are generally exempt from GSA metering but still need a county permit.

    California DWR — SGMA Basin Prioritization (2019) ↗

Hybrid state (appropriation + riparian). Groundwater rules change and basin boundaries follow the aquifer, not the county line — confirm current well and appropriation rules with the California state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in Contra Costa County, California

Is Contra Costa County a good place to live off-grid or homestead?

Contra Costa County scores 27/100 on the Bolthole Index, a weak county profile. Watch-outs: about 599,339 people within a 30-minute drive and elevated mid-century heat, water, rain, or wildfire exposure.

Do you need a building permit in Contra Costa County, California?

Contra Costa County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Contra Costa Health - Environmental Health Division (Land Use Program). Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

Can you live in an RV or tiny home on your land in Contra Costa County?

Living in an RV on your own land in Contra Costa County is limited to specific cases: Human habitation, including sleeping, in a mobile home, recreational vehicle, or travel trailer within unincorporated Contra Costa County land use districts regulated by the County Ordinance Code. The general rule prohibits locating, maintaining, or using a mobile home, recreational vehicle, or travel trailer for human habitation, including sleeping, in any land use district. An exception applies when the use is authorized by Article 84-68.16, 84-68.18, or 84-68.20. A tiny home is limited to specific cases. Confirm with the county before relying on it.

How much does land cost in Contra Costa County, California?

Land in Contra Costa County runs about $9,199 per acre, based on the latest county data.

What is the water situation in Contra Costa County?

Contra Costa County gets about 19.3" of rain a year, with severe drought in roughly 40.4% of years. On water rights, Contra Costa County lies in the East Contra Costa Subbasin — Medium Priority — Medium-priority SGMA basin (DWR 2019 Basin Prioritization) requiring an adopted Groundwater Sustainability Plan; a new well is subject to GSA consistency review under Executive Order N-7-22. De minimis domestic wells (<2 af/yr) are generally exempt from GSA metering but still need a county permit..

How remote is Contra Costa County?

A representative private-land location has about 599,339 people within a 30-minute drive and 12,666,427 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

How Contra Costa compares in California

Compare side-by-side →See all 58 California counties ranked →