Bolthole Index

Trinity County, California

Building permits, zoning and septic rules in Trinity County, California

51Index Score / 100
#11 of 58 in California

Trinity County, California requires a building permit for new construction, issued through the county's Building Division1. The county also has a countywide Zoning Code, so a zoning clearance is reviewed alongside most building permits2. Septic systems go through Trinity County Environmental Health, and a permit is required before you build3. A 2025 county ordinance lets movable tiny homes up to 400 square feet be permitted in any district that allows a single-family home4.

At a glance

Building permit
Required, issued by the county's Building Division1
Zoning
Yes, a countywide Zoning Code (Title 17) reviewed with most building permits2
Septic permits
Required, issued by Trinity County Environmental Health3
Owner-builder
Allowed with owner-builder paperwork; the exemption is from contractor licensing, not permits56
Tiny homes
Allowed where a single-family home is allowed, up to 400 sq ft and one story4
RV living
Generally limited to mobilehome or special occupancy parks unless the county's tiny-home ordinance applies74
Well permits
Required through Environmental Health; $449 for a new well, monitor or soil boring8
Minimum lot size
Five acres (one recorded parcel) in the Unclassified (U) District9

Who to call

Building permits

Trinity County Community Development Department - Building Division

Building permits and inspections for Trinity County, as part of the Community Development Department

530-623-1351

Planning & zoning

Trinity County Community Development Department - Planning Division

Countywide zoning (Title 16 & 17), floodplain management and subdivision review for Trinity County

530-623-1351, ext. 2

530 Main Street, Weaverville, CA 96093

Septic permits

Trinity County Environmental Health Division

Septic (OWTS) and well permits for Trinity County

530-623-1459

[email protected]

Roads & driveways

Trinity County Transportation Department

Encroachment (driveway) permits for work within Trinity County's road right-of-way

530-623-1365

Contact details are copied from each office’s official page and were checked against it on September 28, 2026.

Do you need a building permit in Trinity County, California?

Yes: Trinity County requires a building permit for new construction, and no work may start until the Building Division issues it110. The county's own permit application is direct about it: construction may not start until the building permit is issued, no exceptions10. Trinity County has adopted the California Building Code found in Title 24, Part 2 of the California Code of Regulations, and any newer edition or amendment is adopted automatically11. California law separately requires a permit for each building or structure before work begins, in every county12. The current code cycle matters for timing: the 2025 California Building Standards Code applies to any permit application filed on or after January 1, 2026, so a project that files just before or after that date can land under different rules13. One exception exists: a letter of intent to the Building Division can exempt a qualifying agricultural building, such as a barn or hay shed, from a full building permit, though plumbing and electrical work inside it still needs one14.

Who is the Trinity County building department, and how do you reach them?

Trinity County's Building Division sits inside the Community Development Department, alongside Planning and Environmental Health, and Building and Planning share one department phone line, 530-623-1351, with Planning reachable at extension 21516. The Planning Division's office is at 530 Main Street, Weaverville, California 9609316. A complete building permit application needs a detailed project description, the parcel's APN, a site plan, a building plan, square footage, setbacks and maximum height, and the county returns incomplete applications and can bill extra fees on resubmission17. Every proposed project also has to meet Trinity County's zoning setbacks and Cal Fire's setback requirements before the Building Division signs off17. Have your permit number and parcel address ready when you call: the county asks for at least 24 hours' notice before an inspection18.

Does Trinity County have zoning?

Yes: Trinity County has a countywide Zoning Code under Title 17, covering zoning districts, allowed land uses, setbacks, height limits, density, use permits, variances, temporary uses and accessory structures219. What applies to a given parcel depends on its zoning district, so the county's own guidance is to start by looking up the parcel's zone before assuming a rule applies19. In the Unclassified (U) District, for example, the minimum lot area is one recorded parcel of at least five acres, the maximum building height is 40 feet, structures can't cover more than 25 percent of the lot, and yard setbacks run 20 feet in front, 10 feet on each side and 20 feet in the rear9202122. California law generally lets a county's legislative body adopt zoning ordinances covering building location, height, lot coverage and setbacks countywide, including in unincorporated areas, which is the authority behind rules like these23. Separately, California's statewide ADU law requires Trinity County to approve a qualifying accessory dwelling unit ministerially and issue a written completeness decision within 15 business days24.

How do septic permits work in Trinity County?

Trinity County Environmental Health processes septic permits, and a permit is required before you build wherever a project needs onsite wastewater disposal325. Outside the Weaverville and Hayfork sewer districts and Lewiston's two private sewer companies, a regular septic tank and leach lines are the approved method of sewage disposal described by the county, so most rural buyers should plan around septic feasibility rather than assume a sewer hookup26. Only about 1.1% of Trinity County's mapped soils are free of severe limitations for a conventional septic drain field, making a parcel-specific site evaluation especially important before purchase27. Once a system is installed, Trinity County Environmental Health must verify it at a final inspection before you get a Notice of Final Inspection, and the county recommends pumping a tank every 3 to 5 years28. Statewide, the State Water Board and regional water boards oversee California's onsite wastewater treatment policy, but county environmental health departments like Trinity's implement it directly, including issuing the permits29. The same office is the local agency for water wells: a well, monitor or soil boring permit costs $449, is valid for one year from approval, and drilling can't start until it's issued8. Reach Trinity County Environmental Health at 530-623-1459 or [email protected], Monday through Thursday, 8 a.m. to 2 p.m.30.

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

Trinity County adopted a Movable Tiny Homes ordinance in 2025 that lets a tiny home be permitted in any zoning district that already allows a single-family dwelling by right, including the Unclassified, Agricultural, Agricultural Preserve, Agricultural Forest and Rural Residential districts4. That county tiny home has to stay one story, except for sleeping lofts, and no larger than 400 square feet, be licensed and registered with the DMV or the state Department of Housing and Community Development, get a zoning clearance, and have water and sewage disposal approved by Environmental Health connected before final inspection430. That is a real local answer, and it goes further than California's statewide default: under state law, an RV is not meant for occupancy as a permanent dwelling and generally may only be occupied in a mobilehome park or a special occupancy park unless a local ordinance says otherwise7. Trinity County's tiny home ordinance is that kind of local ordinance, but only for a qualifying movable tiny home; it does not reach a standard travel trailer or RV that doesn't meet the ordinance's DMV/HCD registration and size terms, so confirm your specific unit qualifies with the Planning Division before you buy one to live in164. A manufactured home is a separate, more established path: it can be occupied inside or outside a mobilehome park if it meets Title 25's minimum 8-foot width and 320-square-foot floor area and goes through Mobilehome Parks Act approval31.

Building a home in Trinity County: the steps, in order

  1. Call the Community Development Department at 530-623-1351 to confirm your parcel's zoning district and what a building permit application needs1519.
  2. Apply for a septic (OWTS) permit through Trinity County Environmental Health early: outside the Weaverville and Hayfork sewer districts, a septic tank and leach lines are the only approved method, and only about 1.1% of the county's mapped soils are free of severe limitations for a conventional drain field2627.
  3. If you need a well, apply through the same Environmental Health office: a well, monitor or soil boring permit costs $449, is valid for one year from approval, and drilling can't start until it's issued8.
  4. Get an encroachment permit from the Trinity County Transportation Department before you build or replace a driveway, which costs $150; the county also requires this permit whenever a building, septic or well permit is applied for3233.
  5. Submit a complete Building Division application: a detailed project description, your parcel's APN, a site plan, a building plan, square footage, setbacks and maximum height, checked against Trinity County's zoning setbacks and Cal Fire's setback requirements17.
  6. Expect required inspections at each stage, with at least 24 hours' notice before each one, and a certificate of occupancy only after a final inspection confirms the home meets all applicable codes1834.
  7. If you're creating a new parcel rather than buying an existing one, budget time for California's Subdivision Map Act parcel-map process, which Trinity County administers under Title 16 on top of its own zoning review3536.

What to check before you buy land in Trinity County

Soils: only about 1.1% of Trinity County's mapped soils are free of severe limitations for a conventional septic drain field, so get Environmental Health or a licensed designer to look at any specific parcel before you close2730. Terrain: just 8.9% of the county sits at 15% slope or less, and roughly 87% is wooded, so flat, easily buildable ground is genuinely scarce and site work can run expensive3738. Ownership: about 78% of Trinity County is federal land, which sharply limits how much of the county is even available to buy or build on, so confirm your parcel's boundaries and private status carefully39. Access: if your parcel needs a new or replacement driveway, budget for a $150 county encroachment permit, and know the same permit is required whenever you apply for a building, septic or well permit33. Flood: if any part of the parcel sits in a Special Flood Hazard Area, a new or substantially improved building needs an Elevation Certificate, which the Planning Division can help you get4016. Climate and cost: the county averages about 57.1 inches of precipitation a year with roughly 35% of years in severe drought, a typical home insurance premium near $2,094 a year, and a typical property tax bill around $1,772 a year at an effective rate near 0.5%4142434445.

Watch-outs

  • Only about 1.1% of Trinity County's mapped soils are free of severe limitations for a conventional septic drain field; confirm feasibility with Environmental Health before you buy2730.
  • A generic RV or travel trailer that doesn't meet Trinity County's 2025 tiny-home ordinance is still limited to mobilehome or special occupancy parks under California's default rule; check with the Planning Division before you buy one to live on your land716.
  • About 78% of Trinity County is federal land, so confirm a parcel's private ownership and boundaries carefully before you buy39.
  • Whether short-term rentals are allowed on rural land in Trinity County isn't established by any official county page found for this guide; ask the Planning Division before listing a property16.

Sources

  1. Building Permit Application (2026 county census)
  2. Resources and FAQs (2026 county census)
  3. Resources and FAQs (2026 county census)
  4. Ordinance No. 1375 — Movable Tiny Homes, quoted and re-checked
  5. Building Permit Application (2026 county census)
  6. Building Permit Application, quoted and re-checked
  7. Information Bulletin 2016-01: Tiny Homes (California statewide rule), quoted and re-checked
  8. Water Well / Monitor / Soil Boring Permit Application, quoted and re-checked
  9. Ordinance No. 315, Section 11 — Unclassified or U District, quoted and re-checked
  10. Building Permit Application, quoted and re-checked
  11. Trinity County 2019-2024 Housing Element Update, quoted and re-checked
  12. Do I need a building permit for my project? (California statewide rule), quoted and re-checked
  13. Approved Building Standards (California statewide rule), quoted and re-checked
  14. Ordinance No. 1373 — Agricultural Exemption Ordinance, quoted and re-checked
  15. Trinity County Community Development Department - Building Division (trinitycounty.ca.gov)
  16. Trinity County Community Development Department - Planning Division (trinitycounty.ca.gov)
  17. Trinity County Building Permit Planning Review Checklist, quoted and re-checked
  18. Building Permit Application, quoted and re-checked
  19. Resources and FAQs, quoted and re-checked
  20. Ordinance No. 315, Section 11 — Unclassified or U District, quoted and re-checked
  21. Ordinance No. 315, Section 11 — Unclassified or U District, quoted and re-checked
  22. Ordinance No. 315, Section 11 — Unclassified or U District, quoted and re-checked
  23. California Government Code Section 65850 (California statewide rule), quoted and re-checked
  24. Accessory Dwelling Unit Handbook March 2026 (California statewide rule), quoted and re-checked
  25. Resources and FAQs, quoted and re-checked
  26. Trinity County 2019-2024 Housing Element Update, quoted and re-checked
  27. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
  28. Trinity County OWTS Construction Standards and Minimum Requirements, quoted and re-checked
  29. Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy) (California statewide rule), quoted and re-checked
  30. Trinity County Environmental Health Division (trinitycounty.ca.gov)
  31. Information Bulletin 2016-01: Tiny Homes (California statewide rule), quoted and re-checked
  32. Trinity County Transportation Department (trinitycounty.ca.gov)
  33. Encroachment Permits, quoted and re-checked
  34. Building Permit Application, quoted and re-checked
  35. California Government Code Section 66424 (California statewide rule), quoted and re-checked
  36. Resources and FAQs, quoted and re-checked
  37. Share of land at 15% slope or less: Bolthole Index county data
  38. Wooded share of land: Bolthole Index county data
  39. Federal land share: Bolthole Index county data
  40. Floodplain Management, quoted and re-checked
  41. Annual precipitation: Bolthole Index county data
  42. Share of years in severe drought: Bolthole Index county data
  43. Typical home insurance premium: Bolthole Index county data
  44. Median property tax bill: Bolthole Index county data
  45. Effective property tax rate: Bolthole Index county data

Written September 28, 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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County locator

Trinity County in California

51
County map
Trinity County highlighted among the California counties · colored by Index score

How Trinity County scores

Seclusion81100% ev.
Self-Sufficiency45100% ev.
Admin Boringness41100% ev.
Durability22100% ev.
Property Autonomy56100% ev.
Carry Cost78100% ev.

Evidence strength: 100%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$258kTypical home
0.5%Property tax
$2,661Land / acre
57.1"Annual rain
35.4% of yrsSevere drought
6.6 / yr (+4.7)Mid-century 100°F days
50.3 daysMid-century dry spell
3.31" (+4.4%)Mid-century 1-day rain
1.13×Wildfire change factor
100%Forward climate coverage
$2,094Home insurance / yr
9.1% / yrInsurance growth
2.41%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
3,152Radius comparison (15 mi)
4.9People / sq mi
78.3%Federal land
8.9%Land at 15% slope or less
1.1%Septic soil without severe limits
18,687 acWorkable land screen
87.4%Wooded land
92.8 tonsBiomass / forest ac
52.9°FAvg temp

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Answers from the rulebook for Trinity County

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

Trinity County rules

  • Building permitRequired

    Construction work requiring approval from the Trinity County Building Division.

    • Work may not proceed until specific approval and the required permit are obtained.
    • The permit does not authorize violation of other state or local construction laws.
    • For dwellings and other structures needing services, sewer and water connection approval is required before permit issuance where applicable.
    • In areas not served by a sanitation district, private sewage-disposal approval from Trinity County Environmental Health is required before obtaining a building permit.
    “CONSTRUCTION MAY NOT START UNTIL THE BUILDING PERMIT IS ISSUED. NO EXCEPTIONS!”
  • Owner-builder exemptionConditional

    An owner applying for a Trinity County construction permit as the owner-builder.

    • The county will not issue the building permit until the owner-builder acknowledgment and information verification form has been read, initialed, signed, and returned.
    • The property owner must complete and sign the form; an agent cannot execute the notice without prior approval from the permitting authority.
    • The owner-builder is the responsible party of record and legally and financially responsible for the proposed construction activity.
    • An owner-builder building a single-family residential structure cannot legally build it with intent to offer it for sale unless all work is performed by licensed subcontractors and no more than four structures are built within a calendar year, or all work is under contract with a licensed general building contractor.
    • The owner-builder must comply with applicable owner-builder and employer laws.

    employee-work threshold: >= 500 USD (If persons other than California licensed contractors are employed or engaged, the owner may be considered an employer.) · single-family structures offered for sale: <= 4 structures per calendar year (Alternatively, all work may be performed under contract with a licensed general building contractor.)

    “I understand building permits are not required to be signed by property owners unless they are responsible for the construction and are not hiring a licensed Contractor to assume this responsibility. I understand as an "Owner-Builder" I am the responsible party of record on the permit.”
  • Building code adoptedAdopted (with conditions)

    Building construction subject to Trinity County's adopted California Building Code requirements.

    • Trinity County adopted the California Building Code in California Code of Regulations Title 24, Part 2, Volumes 1 and 2.
    • All more recent editions and amendments are adopted by reference automatically under County Municipal Code Section 15.04.010.A.
    • The County has not adopted additional regulations or amendments that would hinder or add cost to development.
    • The source states that the County encourages voluntary compliance, but it also states that the County may act when construction is performed without a permit and may investigate building-code violations on a complaint basis.

    code: California Building Code (California Code of Regulations Title 24, Part 2, Volumes 1 and 2) · automatic adoption: all more recent editions and amendments (Adopted by reference under Municipal Code Section 15.04.010.A)

    “Trinity County has adopted the California Building Code of the California Code of Regulations Title 24, Part 2, Volumes 1 and 2.”
  • InspectionsRequired

    Permitted building construction inspected by the Trinity County Building Division.

    • The permit holder or agent must notify the Building Department when work is ready for inspection, giving at least 24 hours' notice.
    • Required inspections include foundation, underfloor plumbing, roof sheathing, four-way framing/rough electrical/rough plumbing/mechanical, insulation, lath or wallboard, and final inspection.
    • Inspection requests must include the permit number, inspection type, job location, requester name and phone number, and requested date.
    • Most county areas have specific inspection days shown on the building permit.

    inspection notice: >= 24 hours

    “The permit holder or his agent must notify the Building Department when the work is ready for inspection, giving at least 24 hour notice.”
  • Certificate of occupancyRequired

    Dwellings processed through the Trinity County Building Division after completion and final inspection.

    • The certificate is issued after final inspection when the dwelling complies with all applicable codes and ordinances and is ready for permanent occupancy.
    • A certificate of occupancy is required before obtaining permanent utility connections.
    • The source application describes this requirement for dwellings; applicability to other occupancy types may vary.
    “CERTIFICATE OF OCCUPANCY. Issued after final inspection when the dwelling complies with the provisions of all applicable codes and ordinances and is ready for permanent occupancy. Required prior to obtaining permanent utility connections.”
  • County-wide zoningPresent (with conditions)

    Land use, zoning districts, and development standards administered under Trinity County Title 17.

    • Specific requirements vary by zoning district and development proposal.
    • The source identifies Title 17 as regulating what can be built and how land may be used; it does not establish that every parcel has identical standards.
    “Title 17 regulates land use, zoning districts, and development standards”
  • Local zoningVaries (with conditions)

    Countywide aggregate of local zoning controls; actual requirements vary by parcel zoning district and applicable development standards.

    • The county source identifies zoning districts, allowed land uses, setbacks, height limits, density, use permits, variances, temporary uses, and accessory structures as Title 17 topics.
    • A parcel-specific determination requires identifying the parcel's zoning district and reviewing the applicable district standards.
    “It is best to start with reviewing the allowed uses based on the parcels zone”
  • Zoning districtsPublished (with conditions)

    Trinity County zoning districts and parcel-level zoning information.

    • The County publishes a Zoning Ordinance and Zoning Matrix through the Planning Division.
    • The Zoning Matrix is for early planning purposes and does not by itself determine overall compatibility, timeline, cost, or probability of approval.
    • The County's zoning code update remains under public review, and the County states the update has been extended into 2027; current operative zoning should therefore be confirmed against the adopted code and applicable parcel information.
    • The Flood Hazard (FH) and Flood Hazard Overlay (FHO) districts are separately described in Section 29.4 of the County zoning ordinance.
    “Use this matrix to determine which Zoning Districts may be compatible to rezone a parcel using a parcel's General Plan Designation.”
    One more reviewed finding on this topic
    • Published (with conditions) — County zoning districts and zoning-district compatibility information in Trinity County.
      “Use this matrix to determine which Zoning Districts may be compatible to rezone a parcel using a parcel's General Plan Designation. This should be used for early planning purposes only and does not necessarily determine the overall compatibility, timeline, cost, or probability of approval. Please set up an appointment with a planner to discuss your specific options.”
  • Minimum lot sizeSpecified

    Lots in Trinity County’s Unclassified or U District.

    • For subdivision purposes, appropriate zoning is determined as part of the subdivision process.
    • For other entitlement requests, appropriate zoning is determined as necessary before issuance of the entitlement.

    minimum lot area: >= 5 acres (one recorded parcel)

    “D. LOT DIMENSIONS: The minimum lot area shall be one (1) recorded parcel not less than five (5) acres in area.”
  • SetbacksSpecified

    Buildings in Trinity County’s Unclassified or U District.

    • The ordinance separately specifies front, side, and rear yard requirements.
    • Other parcel-specific zoning or overlay requirements may also apply.

    front yard setback: >= 20 feet · side yard setback: >= 10 feet (each side yard) · rear yard setback: >= 20 feet (for any portion of the building)

    “G. FRONT YARD: Front yards shall have a minimum depth of twenty (20) feet. H. SIDE YARD: Each side yard shall have a minimum width of ten (10) feet. I. REAR YARD: There shall be a rear yard not less than twenty (20) feet in depth for any portion of the building.”
  • Lot coverageSpecified

    Structures in Trinity County’s Unclassified or U District.

    • The limit applies to the total land area covered by structures.
    • The ordinance also contains separate yard and height requirements.

    maximum lot coverage by structures: <= 25 percent

    “J. MAXIMUM LOT COVERAGE: The total land area covered by structures shall not exceed twenty-five percent of the total area of the lot.”
  • Building heightSpecified

    Buildings in Trinity County’s Unclassified or U District.

    • The ordinance states a maximum building height; additional fire, overlay, or parcel-specific requirements may apply.

    maximum building height: <= 40 feet

    “F. BUILDING HEIGHT: Maximum building height shall be forty (40) feet.”
  • Tiny homesAllowed (with conditions)

    Movable tiny homes used as dwellings in Trinity County.

    • A zoning clearance is required and applicable fees and charges apply unless exempted by county code.
    • The home must be located in a district allowing a single-family dwelling by right; listed districts include U, A, AP, A-F, RR, R-1, R-2, and qualifying SUD districts.
    • A building permit is required.
    • The home must be licensed and registered with the California Department of Motor Vehicles or Department of Housing and Community Development.
    • The home may not exceed one story except sleeping lofts or exceed 400 square feet.
    • Water and sewage disposal facilities approved by the County Environmental Health Division and applicable community service district must be connected before final inspection and certificate of occupancy.
    • The ordinance was passed June 17, 2025 and takes effect thirty days after passage.

    maximum floor area: <= 400 square feet · maximum stories: <= 1 story (sleeping lofts excepted)

    “Movable Tiny Homes will be permitted in any district that allows a Single-family dwelling allowed use by right.”
  • Who permits septicCounty

    County administration and processing of well and septic permits in Trinity County.

    “Environmental Health processes well and septic permits”
  • Septic permitRequired

    Residential development requiring onsite wastewater disposal in Trinity County.

    • The cited county FAQ describes a project scenario in which the permits are required; project-specific requirements may vary with site conditions and sewer availability.
    • Environmental Health processes septic permits.
    “permits that would be required are: Well permit, septic permit”
  • Septic inspectionRequired

    Installation of an onsite wastewater treatment system in Trinity County.

    • The entire system must meet the stated requirements before final inspection.
    • The Trinity County Environmental Health inspector must verify the system.
    • A finalized map is attached and recorded with the Trinity County Assessor’s Office.
    • The owner receives a Notice of Final Inspection.
    • The source also states septic tanks should be pumped every 3-5 years by a licensed septic pumper.

    routine tank pumping interval: 3-5 years (licensed septic pumper)

    “a final inspection must be scheduled with Trinity County Environmental Health”
  • Off-grid sanitationLimited

    Off-grid or onsite sewage disposal in Trinity County outside areas required to connect to sewer systems.

    • The county source states all remaining communities and outlying areas require individual sewage disposal systems.
    • A regular septic tank and leach lines are stated to be the only approved methods of sewage disposal in the county.
    • Properties within the Weaverville and Hayfork sewer districts must connect to those systems.
    • Lewiston has two private sewer companies serving smaller subdivision parcels that lack adequate room for an individual septic tank.
    • The county’s septic permitting and inspection requirements still apply.
    “regular septic tank and leach lines are the only approved methods”
  • Well permitRequired

    Water wells, monitoring wells, soil borings, and related well work governed by the Trinity County Environmental Health Division.

    • No drilling may begin before the permit is issued and approved.
    • The permit is valid for one year from the date received by TCEH.
    • If it expires after one year, the applicant must restart the process with new information and fees.
    • A reinstatement fee equal to the original fee may keep the permit valid for one additional year without new paperwork or approval processing.
    • If the well has not been drilled within two years, a completely new permitting process is required.
    • A 72-hour minimum notice of intent to seal must be given by the driller.
    • The application requires an application, payment, directions with map, and a site map showing setbacks.
    • The application form lists fees of $449 for a well, monitor, or soil boring and $321 to abandon/destroy.
    • The form was updated 11/21/2024; this revision date is not treated as an effective date.

    permit validity: 1 year from date received by TCEH (reinstatement may extend validity one additional year) · well permit fee: 449 USD (well, monitor, or soil boring) · abandon/destroy fee: 321 USD · notice of intent to seal: >= 72 hours minimum (given by driller)

    “No drilling shall begin prior to the issuance (approval) of this permit.”
  • Mandatory utility hookupSewer (with conditions)

    Properties lying within the Hayfork sewer district.

    • The county source states connection is required for properties lying within the district for health reasons.
    • This claim does not apply countywide or to properties outside the district.
    • District-specific connection procedures and fees were not stated in the opened source.
    “properties lying within the districts to connect”
    One more reviewed finding on this topic
  • Agricultural exemptionConditional

    Agricultural buildings in the unincorporated territory of Trinity County.

    • The agricultural building must be a structure designed and constructed to house implements, hay, grain, poultry, livestock, or other horticultural products.
    • It may not be a place of human habitation, a place where agricultural products are processed or packaged for retail sale, or a place used by the public.
    • Plumbing and electrical work are not exempt and requires a building permit.
    • A letter of intent must be submitted to the Building Division for review.
    • Agricultural buildings are allowed under the exemption only in the listed Unclassified/U, Agricultural/A, Agricultural Preserve/AP, Agricultural Forest, Rural Residential/RR, and qualifying SUD zoning designations.
    • The structure remains subject to all applicable parcel zoning requirements and overlay provisions, including Flood Hazard, Scenic Conservation, and Special Treatment overlays.
    • The Chief Building Official issues the exemption after confirming correct zoning and compliance with the ordinance.
    • The ordinance takes effect thirty days after passage; it was passed June 3, 2025.

    exempt agricultural-building floor area: not specified (exemption is subject to the ordinance’s definition, zoning, letter-of-intent, and other requirements)

    “Agricultural Exempt Structures are still subject to all applicable requirements that are associated with the subject parcel’s zone and any other provisions in the Trinity County Zoning Ordinance; this includes, but not limited to overlay zoning districts (Flood Hazard, Scenic Conservation, Special Treatment, etc.).The Chief Building Official shall issue the exemption upon confirming the subject parcel is correctly zoned and meets the requirements of this section”
  • Subdividing landRegulated (with conditions)

    Creation and adjustment of parcels in Trinity County.

    • Subdivision applications require the applicable tentative parcel or subdivision map process.
    • The county’s application checklist requires an application fee deposit and supporting materials, including legal access, drainage, water, and sewage-disposal information.
    • For proposed parcels served by new sewage systems, two percolation test results are required for each parcel under the county checklist.

    application fee deposit: required (amount not specified on the cited checklist)

    “Title 16 regulates the creation and adjustment of parcels in compliance with California’s Subdivision Map Act. This is to set standards on how land can be divided or adjusted to create legal parcels.”
  • Driveway accessRequired

    Driveway installation or replacement affecting Trinity County right-of-way.

    • The requirement applies to proposed encroachments within, under, or over the County right-of-way.
    • No work within the County right-of-way may begin until the encroachment permit is issued.
    • The official application lists a $150.00 driveway fee.
    • A diagram showing distance and direction to the nearest landmark or intersection is required, and the grading location should be staked and flagged for field review.

    driveway encroachment permit fee: 150 USD

    “An encroachment permit is required for all proposed activities related to the placement of encroachments within, under, or over the County's right-of-way (ROW).”
    2 more reviewed findings on this topic
    • Required — Driveway installation or replacement within, under, or over a County right-of-way, including County-maintained road right-of-way.
      “Some of the activities requiring an encroachment permit include, but are not limited to, are: Driveway or sidewalk installation/replacement”
    • Limited — Driveway installation or replacement, and access to property through the County right-of-way or County-maintained roads, in unincorporated Trinity County.
      “Driveway or sidewalk installation/replacement”
  • Building in a floodplainRequired

    Construction or development within Trinity County areas zoned Flood Hazard (FH) or Flood Hazard Overlay (FHO), including designated special flood hazard areas.

    • A Floodplain Development Permit is required before construction or development begins in FH or FHO areas.
    • In FHO areas, all uses permitted in the underlying zone remain permitted, but the floodplain permit must be obtained before construction and before issuance of any other county entitlement.
    • In FH areas, structures may be permitted only after securing a Floodplain Development Permit and only if no building site lies outside the FH district.
    • Regulatory floodway encroachments, including fill, new construction, substantial improvements, and other development, are prohibited unless a registered professional engineer certifies that the encroachment will not increase the base flood elevation during the base flood discharge.
    • Residential structures generally must have the lowest floor at least two feet above base flood elevation in A, AE, AH, and A1-30 zones; AO zones have separate elevation requirements.
    • Applications may require duplicate scaled plans showing the nature, location, dimensions, elevations, structures, fill, storage, drainage facilities, and other information specified by the Floodplain Administrator.
    • The Planning Director administers the ordinance and may refer a permit to the Planning Commission for hearing and approval.
    • The ordinance is dated May 20, 2010 and identifies Ordinance 315-776A dated October 20, 2009.

    residential lowest floor elevation in A, AE, AH, and A1-30 zones: >= 2 feet above base flood elevation (AO zones have separate depth-number or four-foot-above-highest-adjacent-grade rules.) · floodway encroachment effect: 0 increase in base flood elevation (Required registered professional engineer certification.)

    “A Floodplain Development Permit shall be obtained before construction or development begins within areas zoned FH or FHO”
    2 more reviewed findings on this topic
    • Required — New and substantially improved buildings located in Trinity County's Special Flood Hazard Area.
      “An Elevation Certificate is required for all new and substantially improved buildings in the Special Flood Hazard Area (SFHA).”
    • Required — All new and substantially improved buildings located in the Special Flood Hazard Area in Trinity County.
      “An Elevation Certificate is required for all new and substantially improved buildings in the Special Flood Hazard Area (SFHA).”
  • Permit feesPublished

    Planning-related permit and application fees administered by Trinity County.

    • Environmental Health and Building Division review fees related to Planning Division permits and applications have increased.
    • The county instructs applicants to contact the Planning Division for a project-specific estimate because multiple fees may apply.
    “Planning Fees - Planning Division fee schedule in Title 2.64.050. Please reach out to Planning Division for an estimate for your project as multiple fees from the Planning Division section may apply for your project.”
    One more reviewed finding on this topic
    • Published (with conditions) — County building permit fees and related planning fees in Trinity County.
      “Building Fees 1. 2023 ICC Valuation Sheet (PDF) 2. 2023 Ordinance Adopted Fees (PDF)”
  • Permit processPublished (with conditions)

    County building permit applications and inspections in Trinity County.

    • A complete application requires a detailed project description, APN and address, site plan, building plan, setbacks, square footage, access road, length, width, and maximum height as applicable.
    • The plan approval process can take up to six weeks after complete submittal.
    • Work may not begin until specific approval and the required permit are obtained.
    • Building inspections require calling the inspection line with the permit number, requested date, inspection type, name, and address; same-day scheduling requires a message before 8 a.m.

    plan approval process: up to 6 weeks (Upon complete submittal)

    “THE PLAN APPROVAL PROCESS CAN TAKE UP TO 6 WEEKS UPON COMPLETE SUBMITTAL”
    One more reviewed finding on this topic
    • Published (with conditions) — County building permit applications and planning review in Trinity County.
      “The following items are REQUIRED for a complete Building Permit application: The Building Division will return applications if the following minimum requirements are not provided at the time of the submittal. Failure to submit a complete Building Permit application will result in additional fees billed to the applicant upon resubmission.”

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.”
  • Living in an RVTemporary only (with conditions)

    Occupancy of recreational vehicles as residential units in California.

    • RVs are not intended for occupancy as permanent dwellings.
    • Unless a local ordinance allows otherwise, RV occupancy generally is limited to mobilehome parks or special occupancy parks governed by the Mobilehome Parks Act or Special Occupancy Parks Act.
    • Applicable state or local approval and enforcement requirements depend on the RV's location and classification.

    maximum gross area: <= 400 square feet (Measured at maximum horizontal projections; internal living room area must be less than 320 square feet excluding specified built-in equipment and bath/toilet rooms.)

    “RVs are not intended for occupancy as a permanent dwelling. [...] Unless otherwise allowed by a local ordinance, RVs generally may be occupied only in mobilehome parks or special occupancy parks”
  • 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.”
  • Accessory dwellingsAllowed (with conditions)

    ADUs and junior ADUs subject to California State ADU Law.

    • Approval is ministerial and without discretionary review or a hearing.
    • Development standards must be objective and knowable in advance.
    • The local permitting agency must determine application completeness and provide written notice within 15 business days.
    • If an application is incomplete, the agency must identify missing items and explain how to complete it.
    • Local site, building, health, safety, fire, utility, and other applicable requirements continue to apply.

    written completeness determination: <= 15 business days (Measured from the permitting agency's receipt of the application.) · final written determination after appeal: <= 60 business days (Applies after receipt of the written appeal.)

    “A permit application for an accessory dwelling unit shall be considered and approved ministerially without discretionary review or a hearing [...] A permitting agency shall determine whether an application to create or serve an accessory dwelling unit is complete and provide written notice of this determination to the applicant not later than 15 business days after the permitting agency received the application.”
  • 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.”
    2 more reviewed findings on this topic
    • Limited — RV and trailer camping at Silver Strand State Beach Campground in the San Diego Coast District.
      “Camping Stay Limits: Applies to persons, equipment, or vehicles and any combination thereof [...] Maximum stay of 30 days per calendar year [...] Maximum 7 consecutive days during peak season (May 15 – September 15) [...] Maximum 14 consecutive days during non-peak season”
    • 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”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Short-term rentals — Short-term rental use in Trinity County.

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.

Living off-grid in Trinity County, California

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

Trinity County scores 51/100 on the Bolthole Index, a solid county profile. Its strengths: sparse surroundings — about 3,152 people within 15 miles and manageable long-term carry cost. Watch-outs: elevated mid-century heat, water, rain, or wildfire exposure and more administrative friction around building and land use.

Do you need a building permit in Trinity County, California?

Trinity County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Trinity County Environmental Health. 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 Trinity County?

Living in an RV on your own land in Trinity County is allowed on a temporary basis only: Statewide rule. Occupancy of recreational vehicles as residential units in California. RVs are not intended for occupancy as permanent dwellings. Unless a local ordinance allows otherwise, RV occupancy generally is limited to mobilehome parks or special occupancy parks governed by the Mobilehome Parks Act or Special Occupancy Parks Act. A tiny home is allowed. Confirm with the county before relying on it.

How much does land cost in Trinity County, California?

Land in Trinity County runs about $2,661 per acre, based on the latest county data.

What is the water situation in Trinity County?

Trinity County gets about 57.1" of rain a year, with severe drought in roughly 35.4% of years.

How remote is Trinity County?

A typical private-land location has about 3,152 people within 15 miles and 917,869 within 100 miles. These radius catchments are the published fallback where road routing is unavailable.

Off-grid gear

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

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How Trinity compares in California

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