Bolthole Index

Santa Clara County, California

Building permits, zoning and septic rules in Gilroy, California

Gilroy, California issues building permits for new development and renovation through the city Building Division.1 Gilroy administers city zoning, while Santa Clara County Environmental Health handles septic permits and installation inspections.23 A Gilroy building without an approved public sewer connection needs written health-officer approval of its sewage-disposal plan before building-permit issuance.4

At a glance

Building permits
City Building Division; apply through GO Permit1
Zoning
Gilroy city zoning applies inside city limits2
Septic
County Environmental Health; city requires health-officer approval for non-sewered buildings35
ADUs
Allowed conditionally in residential and mixed-use zones6
ADU setbacks
Generally 4 feet at sides and rear for new construction; conversion exceptions apply6
ADU rentals
Rental terms must be at least 30 days7

Who to call

Building permits

City of Gilroy Building Division

City building-permit applications, plan review and inspections.

408-846-0451

Online permits →

Planning & zoning

City of Gilroy Planning Division

City planning questions and project review.

408-846-0440

[email protected]

7351 Rosanna St. Gilroy, CA 95020

Online permits →

Septic permits

Santa Clara County Department of Environmental Health

County onsite wastewater treatment system permits and installation inspections.

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 Gilroy means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Gilroy, CA?

Gilroy’s Building Division processes building permits for new development and renovation projects, with applications submitted through GO Permit.1 For a proposed home, ask the Building Division to identify the building-permit application and plan-review requirements for your design.1 A non-sewered Gilroy building has an additional prerequisite: the health officer must approve the sewage-disposal plan in writing before a building permit can be issued.4 The same sewage-disposal approval is required before the city issues a certificate of occupancy for a non-sewered building.8

Who handles Gilroy building permits and planning questions?

Reach the Gilroy Building Division at 408-846-0451 for building-permit assistance.1 GO Permit supports online applications, plan-review tracking and inspection scheduling.1 For city planning questions, email [email protected] or call 408-846-0440.9 Ask Planning about the parcel’s zoning and proposed use before committing to a house layout; Gilroy has its own zoning ordinance inside city limits.2 Building permits and zoning approval do not replace septic review: Santa Clara County Environmental Health issues onsite wastewater treatment system permits and conducts installation inspections.3

Does Gilroy have zoning, and what setbacks apply to ADUs?

Gilroy has city zoning; a parcel inside city limits is subject to Gilroy’s zoning ordinance.2 Gilroy allows accessory dwelling units conditionally in residential and mixed-use zones.6 Newly constructed Gilroy ADUs generally need 4-foot side and rear setbacks, with exceptions for specified conversions and replacement structures in the same location and dimensions.6 A detached ADU generally has a 16-foot height limit, with qualifying transit-related exceptions.6 Those ADU dimensions do not establish a primary house’s setbacks or minimum lot size; ask Gilroy Planning for the standards applicable to your proposed use and parcel.69

How do septic permits work inside Gilroy?

Santa Clara County Environmental Health issues permits for new onsite wastewater treatment systems and repairs, and inspects installation.3 Gilroy separately requires sewage-disposal plans to be submitted to the health officer and a sewage-disposal permit obtained before constructing or rebuilding covered buildings without an approved public sanitary sewer connection.10 Written health-officer approval is also a condition of building-permit and occupancy approval for those buildings.5 Ask Environmental Health and the city Building Division to coordinate the sewage-disposal approval with your building application before construction begins.34

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

We could not confirm Gilroy’s complete rules for residential RV occupancy, temporary camping or tiny-home occupancy; ask Gilroy Planning about the exact unit and intended length of stay before buying.9 An approved ADU is a documented housing option in Gilroy residential and mixed-use zones, subject to the city’s ADU requirements.6 Gilroy ADUs cannot be rented for periods shorter than 30 days, and the owner must record a deed restriction before the final building inspection.7 Do not treat an ADU approval as permission to occupy an RV: ask Planning to confirm which approval applies to your proposed unit.69

Building a home in Gilroy: what should you do first?

  1. Confirm the parcel’s city-limit status and ask Gilroy Planning about the proposed residential use under city zoning.29
  2. Establish the sewage-disposal route; for a non-sewered building, submit plans to the health officer and obtain the required approval and sewage-disposal permit.10
  3. Submit the city building-permit application through GO Permit for plan review against state and city codes.1
  4. Use GO Permit to schedule building inspections, and coordinate septic installation inspections with county Environmental Health where an onsite system is proposed.13
  5. For a non-sewered home, secure written health-officer sewage-disposal approval before occupancy certification.8

What should you check before buying land in Gilroy?

For land outside Gilroy city limits, use the Santa Clara County guide for the county building-permit requirements that apply in unincorporated areas.11 For land inside Gilroy, ask city Planning to confirm minimum lot size, primary-house setbacks, agricultural-building requirements, floodplain review and driveway-access approvals; we could not confirm complete city rules for those questions.9 If the project depends on a private well, California requires a permit from the applicable local environmental health agency or water district before well construction, modification or destruction.12 Ask Valley Water whether the parcel falls within its well-permit service area; covered wells require its permit, and water-supply well construction applications also need county Environmental Health approval.13

Watch-outs

  • Gilroy’s non-sewered buildings need written health-officer sewage-disposal approval before both building-permit and occupancy approval.5
  • We could not confirm current Gilroy building-permit fees or a complete RV-living rule; ask the Building Division about fees and Planning about occupancy before committing to a project.19
  • Gilroy ADUs cannot be rented for less than 30 days.7

Sources

  1. City of Gilroy Building Division (cityofgilroy.org)
  2. Table of Contents - City of Gilroy, CA (Gilroy), quoted and re-checked
  3. Onsite Wastewater Treatment System (OWTS), quoted and re-checked
  4. Article II: Sanitary Disposal of Sewage Within City - City of Gilroy, CA (Gilroy), quoted and re-checked
  5. Article II: Sanitary Disposal of Sewage Within City - City of Gilroy, CA (Gilroy), quoted and re-checked
  6. Article LIV: Accessory Dwelling Units - City of Gilroy, CA (Gilroy), quoted and re-checked
  7. Article LIV: Accessory Dwelling Units - City of Gilroy, CA (Gilroy), quoted and re-checked
  8. Article II: Sanitary Disposal of Sewage Within City - City of Gilroy, CA (Gilroy), quoted and re-checked
  9. City of Gilroy Planning Division (cityofgilroy.org)
  10. Article II: Sanitary Disposal of Sewage Within City - City of Gilroy, CA (Gilroy), quoted and re-checked
  11. Apply for a Building Permit, quoted and re-checked
  12. Well Standards (California statewide rule), quoted and re-checked
  13. Well Permits and Inspections, quoted and re-checked

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.

Answers from the rulebook for Gilroy

Gilroy’s own rules

  • Building permitLimited

    A building in Gilroy that is not to be connected to an approved public sanitary sewer.

    • Plans for sewage disposal must be submitted to the health officer.
    • A sewage-disposal permit is required before construction.
    • A building permit cannot be issued without the health officer's written approval.
    “No building permit [...] shall be issued”
  • Certificate of occupancyRequired

    Buildings inside Gilroy that are not connected to an approved public sanitary sewer.

    • Written approval by the health officer of the sewage-disposal means is required before issuance.
    “No certification of occupancy shall be issued”
  • Local zoningPresent

    Land inside Gilroy city limits; the city publishes and administers Chapter 30, Zoning Ordinance.

    “Chapter 30 Zoning Ordinance (§ 30.1.10 – § 30.54.60)”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units inside Gilroy residential and mixed-use zones.

    • ADUs must comply with California Government Code § 66310 et seq. and Article LIV.
    • A detached ADU generally has a 16-foot maximum height; transit-related exceptions allow 18 feet and, when necessary to match the primary dwelling roof pitch, up to 20 feet.
    • A newly constructed ADU generally requires four-foot side and rear setbacks; conversions have stated setback exceptions.
    • An ADU may not be rented for less than 30 days and may not be sold separately except as permitted by Government Code § 66341.

    minimum side/rear setback for new ADU: 4 ft (Not required for conversion of an existing permitted accessory structure, living area, garage space, or structure built in the same location and dimensions.) · maximum detached ADU height: 16 ft (18 feet near qualifying transit; up to 20 feet if necessary to match the primary dwelling roof pitch.)

    “shall be permitted as a single-family residential use”
  • Off-grid sanitationLimited

    Off-grid sewage disposal inside Gilroy city limits.

    • The building must not connect to an approved public sanitary sewer.
    • Plans must be submitted to the health officer and a permit obtained.
    • A building permit and certificate of occupancy also require written health-officer approval.
    “No building permit as required in the city zoning ordinance, and any amendments thereto, shall be issued for any building which is not to be connected to an approved public sanitary sewer, without the written approval of the health officer of the plan of the means of sewage disposal for such building.”
  • Mandatory utility hookupConditional

    New or rebuilt residences and covered buildings inside Gilroy city limits.

    • A building not connected to an approved public sanitary sewer may proceed only after health-officer approval of an alternative sewage-disposal plan and issuance of the required permit.
    • The opened code did not state a distance threshold for sewer availability.
    “It shall be unlawful for any person to construct, build, or rebuild any residence, place of residence, or other building or place where persons congregate, reside or are employed which is not to be connected to an approved public sanitary sewer without first submitting plans of the means of sewage disposal to the health officer, and obtaining a permit therefor as herein provided.”
  • Subdividing landRegulated (with conditions)

    Subdivisions wholly or partially within Gilroy city limits.

    • A subdivision creating five or more parcels requires both a tentative and final map except as allowed by Government Code § 66426.
    • All other subdivisions require a parcel map.
    • The chapter operates pursuant to the Subdivision Map Act and other applicable law.

    parcel threshold for tentative and final maps: >= 5 parcels (Except as permitted under Government Code § 66426)

    “A subdivision creating five (5) or more parcels shall require both a tentative and a final map”
  • Short-term rentalsLimited

    Accessory dwelling units inside Gilroy city limits.

    • The prohibition applies to rentals for periods less than 30 days.
    • The owner must record a deed restriction before the final building inspection.

    minimum rental period for ADU: >= 30 days

    “An accessory dwelling unit shall not be rented for periods less than thirty (30) days. Short-term rentals are prohibited.”
  • Permit processPartial

    Subdivision and non-public-sewer development inside Gilroy city limits.

    • Non-public-sewer construction requires health-officer plans, approval, and permit before building-permit and occupancy approvals.
    • Subdivisions are processed under Chapter 21 and the Subdivision Map Act.
    • The zoning table identifies principal, conditional, and temporary-use approvals.
    “shall apply to all subdivisions hereafter made of land wholly or partially within the city”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Gilroy or Santa Clara County directly.

  • Owner-builder exemption — Owner-builders inside Gilroy city limits.
  • Minimum dwelling size — Primary dwellings in Gilroy residential districts.
  • Lot coverage — Residential districts inside Gilroy city limits.
  • Living in an RV — Residential or long-term occupancy of recreational vehicles inside Gilroy city limits.
  • Camping on your land — Temporary camping on private land inside Gilroy city limits.
9 more unanswered
  • Tiny homes
  • Manufactured homes
  • Who permits septic
  • Septic inspection
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Permit fees

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 Gilroy publishes no rule on the point, not that none exists. Santa Clara County’s page lists the county offices to call.

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