Bolthole Index

Contra Costa County, California

Zoning, building permits and septic rules in Orinda, California

Orinda, California (Contra Costa County) administers its own zoning, and most construction and demolition projects inside city limits require a building permit.12 The City's Planning Department reviews zoning compliance, while Contra Costa County's Department of Conservation and Development issues the permit and inspects the work.3 Septic systems and wells are handled by Contra Costa Health Environmental Health, which applies its land-use rules inside Orinda too.4

At a glance

Building permit
Required for most construction and demolition, with listed exceptions2
Who issues it
Contra Costa County, after Orinda Planning review5
Zoning
Orinda Title 17; eleven residential districts16
Septic
Contra Costa Health reviews plans and inspects construction7
Accessory dwelling
Permitted by right on qualifying single-family lots8
Short-term rental
Annual registration and quarterly transient occupancy tax9
RV in a flood zone
Under 180 consecutive days on site, or meet permit, elevation and anchoring rules10

Who to call

Planning & zoning

City of Orinda Planning Department

Zoning, land-use entitlements and Planning review of building permits inside Orinda city limits; building plan check and inspection are provided by Contra Costa County

925-253-4210

22 Orinda Way, Orinda, CA 94563

Building permits

Contra Costa County Department of Conservation and Development Permit Center

Building plan check, permit issuance and inspections for projects inside Orinda city limits

925-655-2700

30 Muir Road, Martinez, CA 94553

Septic permits

Contra Costa Health - Environmental Health Division

Onsite wastewater (septic) and well plan review and inspection, including inside incorporated cities

925-608-5500

2120 Diamond Boulevard, Suite 100, Concord, CA 94520

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Off-grid gear

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

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Do you need a building permit in Orinda, California?

Yes, for most work. With some exceptions, most construction and demolition projects inside Orinda require a construction permit.2 A building permit is required before anyone erects, constructs, enlarges, alters, repairs, moves, improves, removes, converts or demolishes a building or structure, and the city publishes a list of projects that do not need one.3

Orinda adopted the 2022 California Building Code in January 2023, with fire-resistant construction requirements for new, altered or added buildings.11

We could not confirm a separate owner-builder exemption or a certificate-of-occupancy rule inside Orinda; the city says an owner may obtain a permit.2

Who issues building permits in Orinda, and how do you reach them?

Two agencies share the job. The City of Orinda Planning Department reviews every project that needs a building permit for zoning compliance, except projects exempt from Planning review, and Contra Costa County's Department of Conservation and Development Permit Center, at 30 Muir Road, Martinez, provides building plan check and inspections.35 The county permit center's number is 925-655-2700.12

Orinda Planning is at 22 Orinda Way, phone 925-253-4210, and accepts applications only through its online portal; emailed submittals are not accepted.3

Once the county tells you the permit is ready, the application can expire after 180 days, and work must commence within 12 months.5

Septic permits and wells go through a different agency, Contra Costa Environmental Health, at 925-608-5500.13

Does Orinda have zoning, and what does it mean for homes and lots?

Yes. Orinda administers Title 17 zoning, which defines eleven residential districts.1 They are RVL-E, RVL, RL-40, RL-20, RL-15, RL-12, RL-10, RL-6, RM, RH-25 and RH-40.6

Lot formation and reconfiguration are subject to the code's minimum lot size chapter and its lot line adjustment chapter, and the city also publishes SB 9 lot-split application materials.14

Second units (in-law apartments) are permitted by right on lots in single-family zones that meet certain criteria.8 A manufactured home can be used as a residence in a single-family zone if it is built no more than 10 years before application, certified under the federal standards and fixed to an approved permanent foundation.15

We could not confirm a minimum dwelling size or lot-coverage percentage; ask Orinda Planning at 925-253-4210.3

How do septic permits work in Orinda, California?

Septic permits come from the county, not the city. Contra Costa Health Environmental Health reviews design plans and inspects the construction of septic systems, and final approval is required before the system is placed in service.7 The county's land-use regulations apply to all construction in Contra Costa County, including incorporated city properties.4

Call 925-608-5500.13

Soils are a real constraint: only about 0.5% of soils in Contra Costa County rate as not very limited for a conventional drain field, so expect a site evaluation and possibly an engineered system.16

We could not confirm a general rule requiring connection to public water or sewer, or the well-permit requirement, for Orinda parcels.

Can you live in an RV or tiny home on your land in Orinda?

We could not confirm a general rule for living in an RV or tiny home on private land in Orinda. Camping in city parks needs a permit, and no one may lodge in a motorhome within a park.17

Where a site lies in a mapped flood zone, an RV must either be on site fewer than 180 consecutive days, be licensed and ready for highway use, and have no permanent additions, or meet the city's permit, elevation and anchoring requirements.10

No official source we reviewed addresses tiny homes as a distinct use. Ask Orinda Planning at 925-253-4210 before placing one.3

Building a home in Orinda: the steps, in order

  1. Confirm the zoning district and talk to Orinda Planning by appointment.3
  2. If the lot uses septic or a well, get Contra Costa Environmental Health review first.4
  3. Submit your building permit application online to Orinda Planning for zoning review.3
  4. Send approved plans to Contra Costa County for plan check, fees and the permit.5
  5. Start work within 12 months and pass the first inspection.5
  6. Have the septic system inspected and approved before use.7

What to check before you buy land in Orinda, California

Check the driveway. A driveway must not enter a roadway within 5 feet of existing or planned curb returns.18

Check the flood zone. RV and manufactured-home placement rules in mapped flood zones add elevation and anchoring requirements.10

If you plan a rental, Orinda requires short-term rental registration, renewed every year, and quarterly transient occupancy tax payments.9

Watch-outs

  • Orinda Planning approves zoning, but the county issues the building permit, so budget time for both.5
  • Septic and well rules come from Contra Costa Environmental Health and apply inside the city.4
  • We could not confirm tiny-home, well-permit, lot-coverage or agricultural-exemption rules inside Orinda.3

Sources

  1. Orinda Municipal Code § 17.3.2, Residential district descriptions (Orinda), quoted and re-checked
  2. All About Building Permits (Orinda), quoted and re-checked
  3. City of Orinda Planning Department (cityoforinda.org)
  4. Land Use Program (Orinda), quoted and re-checked
  5. cityoforinda.org (Orinda), quoted and re-checked
  6. Orinda Municipal Code § 17.3.2, Residential district descriptions (Orinda), quoted and re-checked
  7. Land Use Program (Orinda), quoted and re-checked
  8. General Plan and Housing Element, Chapter 5 (Orinda), quoted and re-checked
  9. Short-Term Rental Handout (Orinda), quoted and re-checked
  10. Orinda Municipal Code § 18.05.210, Standards for recreational vehicles (Orinda), quoted and re-checked
  11. cityoforinda.org (Orinda), quoted and re-checked
  12. Contra Costa County Department of Conservation and Development Permit Center (cityoforinda.org)
  13. Contra Costa Health - Environmental Health Division (cchealth.org)
  14. Orinda Municipal Code § 17.4.2, Residential property development regulations (Orinda), quoted and re-checked
  15. Orinda Municipal Code § 17.4.30, Manufactured homes (Orinda), quoted and re-checked
  16. 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
  17. Orinda Municipal Code § 12.28.300, Camping (Orinda), quoted and re-checked
  18. Revocable Encroachment Permit (Orinda), quoted and re-checked

Written October 10, 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.

Answers from the rulebook for Orinda

Orinda’s own rules

  • Building permitRequired

    Most construction and demolition projects inside Orinda city limits; permits are processed by Contra Costa County Building Department on behalf of Orinda.

    • Exceptions exist under the applicable work-exempt-from-permits provisions.
    • The official page states that most construction and demolition projects require a construction permit.
    “With some exceptions, (see Work Exempt from Permits): most all construction and demolition projects require a construction permit.”
  • Building code adoptedAdopted

    Buildings in Orinda city limits.

    • Ordinance 23-01 includes fire-resistant construction requirements for new, altered, or added buildings.
    “In January 2023, the City Council adopted the 2022 California Building Code”
  • Local zoningPresent

    Orinda city limits; the City administers Title 17 residential zoning districts.

    “There are eleven (11) residential districts in the City of Orinda, as follows.”
  • Zoning districtsPublished

    Orinda city limits; Title 17 publishes residential zoning districts.

    • The code identifies eleven residential districts: RVL-E, RVL, RL-40, RL-20, RL-15, RL-12, RL-10, RL-6, RM, RH-25, and RH-40.
    “There are eleven (11) residential districts in the City of Orinda, as follows.”
  • Living in an RVLimited

    Recreational vehicles placed on sites inside Orinda city limits that are within FEMA Zones A1-30, AH, or AE.

    • The RV must either be on site fewer than 180 consecutive days, fully licensed, ready for highway use, on wheels or a jacking system, attached only by quick-disconnect utilities and security devices, and have no permanently attached additions; or satisfy the permit, elevation, and anchoring requirements cross-referenced in §§ 18.05.100 and 18.05.200.
    • Separate city parking permits regulate oversized recreational vehicles in residential areas.

    maximum consecutive days under temporary option: < 180 days (must also be fully licensed and ready for highway use)

    “Be on the site for fewer than one hundred eighty (180) consecutive days, and be fully licensed and ready for highway use.”
  • Camping on your landLimited

    Camping in Orinda city parks.

    • A permit is required.
    • No person may lodge in a motorhome within a park.
    • The rule is specific to parks and does not establish a citywide private-property camping rule.
    “No person may camp without a permit. No person may lodge in a motorhome within a park.”
  • Manufactured homesAllowed (with conditions)

    A mobile or manufactured home used as a residence in a single-family residential zone inside Orinda city limits.

    • It must meet all applicable residential-development requirements, including setbacks, paving, height, materials, width, parking, and accessory-structure rules.
    • It must be manufactured and certified under the National Mobile Home Construction and Safety Standards Act of 1974 and built no more than ten years before application.
    • It must be fixed to an approved permanent foundation.
    • Building, plumbing, and electrical permits are required as specified in the section.
    • Flood-zone placement is subject to separate elevation and anchoring requirements.

    maximum age at application: <= 10 years (must also satisfy the other requirements in § 17.4.30)

    “A mobile home may be used as a residence in any single-family (one-family) residential zone if it meets all of the following requirements”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units on qualifying residential lots inside Orinda city limits.

    • The official city housing material states that second units are permitted by right in single-family zones when specified criteria are met.
    • The municipal code defines an ADU as attached or detached, with complete independent living facilities, on a lot with an existing or proposed primary dwelling.
    • Separate state-law and municipal-code standards may apply.
    “Second units (in-law apartments) are permitted by right on lots in single-family zones that meet certain criteria.”
  • Who permits septicCounty

    Properties inside Orinda city limits using septic systems or water wells; Contra Costa Health Environmental Health administers the county land-use review.

    • The county page states the rules apply throughout Contra Costa County, including incorporated city properties within the county.
    “There are land use regulations for all construction in Contra Costa County”
  • Septic inspectionRequired

    OWTS construction and related land-use work inside Orinda city limits.

    • Contra Costa Health reviews and inspects septic-system construction.
    • Final approval is required before placing the system in service.
    “reviewing design plans and inspecting the construction of septic systems”
  • Subdividing landRegulated (with conditions)

    Lot formation and reconfiguration inside Orinda city limits.

    • Residential lot formation and reconfiguration are subject to Chapter 17.7 and Chapter 17.20.
    • The City also publishes SB 9 lot-split application materials for qualifying projects.
    “lot formation and reconfiguration are subject to the provisions of Chapter 17.7 (Residential Minimum Lot Size) and Chapter 17.20 (Lot Line Adjustments)”
  • Driveway accessLimited

    Driveways entering public roadways or affecting the public right-of-way inside Orinda city limits.

    • A driveway must not enter within 5 feet of existing or planned curb returns.
    • It must not interfere with a legal encroachment or create a hazard or nuisance.
    • Driveway construction and right-of-way work are subject to the City permit and inspection conditions.

    minimum distance from curb return: >= 5 feet (existing or planned curb returns)

    “The driveway shall not enter a roadway within 5' of existing or planned curb returns”
  • Short-term rentalsLimited

    Short-term rentals inside Orinda city limits.

    • Registration is required and must be renewed annually.
    • A transient occupancy tax must be paid quarterly.
    • Listings must identify the city's registration number.
    • Streamlined ADUs approved after January 1, 2020 may not be used for short-term rentals.
    • Rentals requiring a minimum 30-day stay are long-term rentals that the city does not currently regulate.

    registration validity: 1 year (must be renewed annually)

    “Registration is valid for one year from date of issuance and must be renewed annually.”
  • Permit processPublished (with conditions)

    Housing-related building permits inside Orinda city limits.

    • Contra Costa County Building Department processes housing-related permits on behalf of Orinda.
    • Orinda Planning performs plan checks and inspections for housing projects.
    • The county permit page states applications may be abandoned after 180 days without response to review comments and expire 180 days after notice that the permit is ready to issue.

    application response period: 180 days (failure to respond to county review comments may deem application abandoned) · permit commencement period: 12 months (work must commence; first inspection must pass)

    “the application will be deemed abandoned.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Orinda or Contra Costa County directly.

  • Owner-builder exemption — Owner-builders seeking construction permits inside Orinda city limits.
  • Certificate of occupancy — Buildings inside Orinda city limits.
  • Minimum dwelling size — Primary dwellings in Orinda residential districts.
  • Lot coverage — Residential lots inside Orinda city limits.
  • Tiny homes — Tiny-home occupancy inside Orinda city limits.
4 more unanswered
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption

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.

Unanswered questions are usually a sign that Orinda publishes no rule on the point, not that none exists. Contra Costa County’s page lists the county offices to call.

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