You are viewing the permanent link for the record currently in effect, published 2026-07-07.
Unincorporated Cassia County building permits
VerifiedUnincorporated Cassia County, Idaho — as published 2026-07-07.
Verified 2026-07-08 · Source
Codes adopted
Permit types & fees
Residential Building Permit (New Construction / Addition)
VerifiedRequired for new single-family dwellings, additions, garages, shops, decks, and other structures covered under the International Building/Residential Code in unincorporated Cassia County. Issued by the Cassia County Zoning and Building Department under Title 11, Chapter 1 of the County Code. Applications are submitted in person or by mail with two sets of plans; electrical, plumbing, and HVAC are permitted separately through the Idaho Division of Building Safety (DOPL), not the county.
Verified 2026-07-08 · Source
Requirements
- Building permit required for new residential construction, additions, and structural alterations covered under the 2018 IBC/IRC as adopted by Cassia County (Title 11, Chapter 1; County Code 11-1-4)
- Minimum one (1) acre of property required for any residence (County Code 9-4-2 a/b/c)
- Recorded Deed Number required for new residential construction (submit copy)
- Septic Permit Number required — obtained from South Central Public Health District, 485 22nd Street, Heyburn, ID 83336, phone 208-678-8221 (submit copy)
- Drive Approach Permit Number from the applicable Highway District, if required (submit copy)
- Applicable Irrigation District/Canal Company and Fire District notification and signature required on the application
- Site plan/plot map showing distances from road centerline (min. 54 ft) and interior property lines (15 ft for dwellings, 10 ft for accessory buildings), with at least one building corner tied to a property line or corner
- Two sets of plans required: Site Plan, Foundation/Basement Plan, Floor Plan, Elevation Plan, Siding/Roof Pitch, Wall Cross Section, Window & Door Schedule/Rescheck (Energy Code Compliance Analysis)
- Agricultural Waiver (signed and notarized) required prior to submittal for Prime Agricultural (AP), Agricultural Residential (AR), or Multiple Use (MU) zones
- Non-refundable plan review fee required with application submittal, applied toward the total building permit fee
- Contractor Registration Number (Idaho) and expiration date required if using a contractor
Required documents
- RequiredCassia County Building Permit Application (2025)Primary residential/commercial building permit application; available at cassia.gov/county-forms-applications
- RequiredPlot Map / Site PlanMust show distances from road center and interior property lines to project, with at least one building corner tied to a property line or corner; page 3 of the Building Permit Application
- RequiredTwo Sets of Construction Plans (Site, Foundation, Floor, Elevation, Siding/Roof Pitch, Wall Cross Section, Window & Door Schedule/Rescheck)Required submittals per item 15 of the Building Permit Application
- RequiredSeptic Permit (copy)Obtained from South Central Public Health District, required with application
- OptionalRecorded Deed Number (copy)Required for new residential construction only
- OptionalAgricultural Waiver (signed, notarized)Required prior to submittal for AP (9-7-3 C), AR (9-7-2 C), or MU (9-7-4 E) zoned parcels; form available at cassia.gov/county-forms-applications
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building permit fee | Calculated based on square footage using the IBC 2003 Valuation Table 1 | Cassia County Administrative Fees schedule, Building Department section (cassia.gov/administrative-fees); fee amount authorized by Board of County Commissioners resolution per County Code 11-1-6 |
| Plan Review — Residential | $200.00 | Non-refundable, applied to total building permit fee; Cassia County Administrative Fees schedule |
| Re-inspection / not-ready-for-inspection fee | $30.00 per hour (1 hour minimum) | Charged if the project is not ready for inspection at the scheduled appointment time; Cassia County Building Permit Application (2025) |
Accessory Dwelling Unit (ADU) Permit
VerifiedRequired before constructing or modifying an Accessory Dwelling Unit (ADU) in unincorporated Cassia County. Governed by County Code Title 9, Chapter 9 (9-9-4 W). ADUs must be 300–1,000 sq ft, limited to one per lot, placed on a permanent foundation, connected to the Principal Dwelling Unit's utilities, and require a recorded Declaration of Restrictions filed with the County Recorder before the permit is issued.
Verified 2026-07-08 · Source
Requirements
- Property must have an existing or proposed Principal Dwelling Unit (PDU); no ADU permitted without a PDU on the lot
- Lot must meet minimum lot size of one (1) acre
- ADU must be 300–1,000 sq ft (excluding garage and non-living areas), and only one ADU is permitted per residentially zoned lot
- ADU must be on a permanent foundation and declared real property under Cassia County Code
- ADU must connect to the Principal Dwelling Unit's utilities (water, waste) — no separate well or independent utility service permitted; septic/waste handling for the ADU must be pre-approved by South Central Public Health District
- Recorded Declaration of Restrictions must be filed with the County Recorder before the ADU permit is issued, confirming the ADU will not be sold separately from the PDU and is capped at 1,000 sq ft
- Site plan/plot map, septic permit copy, drive approach permit copy, irrigation/fire district letters, and utility services acknowledgement required
- Occupancy permit must be issued by the Building Department prior to occupancy of the ADU
- Agricultural Waiver required for AR-zoned parcels per County Code 9-7-2(C)
Required documents
- RequiredCassia County Accessory Dwelling Unit (ADU) Permit Application Packet (2-4-25)Six-page combined application, checklist, and deed restriction template; available at cassia.gov/county-forms-applications
- RequiredRecorded Declaration of RestrictionsTemplate included in the ADU application packet (pages 4-6); must be recorded with the Cassia County Recorder prior to permit issuance per County Code 9-9-4 W(8)
- RequiredSeptic Permit (copy)Pre-approval from South Central Public Health District required for ADU waste handling
- RequiredPlot Map / Site PlanSame requirements as standard building permit — road/interior setback distances and building-corner tie to property line
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building permit fee (ADU, new construction) | Calculated based on square footage using the IBC 2003 Valuation Table 1 | Same fee structure as the standard residential building permit; Cassia County Administrative Fees schedule |
| Placement Fee — Single Section (if ADU is a manufactured home) | $150.00 | Without permanent foundation; Cassia County Administrative Fees schedule / ADU Permit Application |
| Placement Fee — Multi-Section (if ADU is a manufactured home) | $200.00 | Without permanent foundation; Cassia County Administrative Fees schedule / ADU Permit Application |
Manufactured/Mobile Home Placement Permit
VerifiedRequired prior to installing a manufactured or mobile home in unincorporated Cassia County, whether set on block/tie-down or a permanent foundation. Issued by the Cassia County Zoning and Building Department; homes manufactured before June 15, 1976 require a Mobile Home Compliance Rehabilitation Certificate from the Idaho Department (Division) of Building Safety before a placement permit can issue.
Verified 2026-07-08 · Source
Requirements
- Placement permit required prior to installation of any manufactured/mobile home
- Taxes must be paid in full — verified by County Treasurer's Office signature on the application
- Manufactured home information required: month/date/year of manufacture, model, and serial number
- Homes manufactured prior to June 15, 1976 require a Mobile Home Compliance Rehabilitation Certificate from Idaho DOBS/DOPL before permit issuance (Idaho Code Title 44, Chapter 25)
- Septic Permit Number required (copy submitted) unless connecting to an approved system already in place
- Flood Plain Review required — Cassia Flood Plain Manager must confirm whether the parcel is in a flood plain
- Drive Approach Permit Number from applicable Highway District, if required
- Applicable Irrigation District/Canal Company and Fire District notification and signature required
- Site Setback and Final inspections required
Required documents
- RequiredCassia County Manufactured Home Placement Permit Application (2025)Application and checklist for manufactured/mobile home placement; available at cassia.gov/county-forms-applications
- OptionalMobile Home Compliance Rehabilitation CertificateRequired only for homes manufactured before June 15, 1976, issued by Idaho Department of Building Safety (DOPL)
- RequiredSeptic Permit (copy)From South Central Public Health District
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Placement Fee — Single Section (without permanent foundation) | $150.00 | Cassia County Administrative Fees schedule / Manufactured Home Placement Permit Application (2025) |
| Placement Fee — Multi-Section (without permanent foundation) | $200.00 | Cassia County Administrative Fees schedule / Manufactured Home Placement Permit Application (2025) |
| Concrete Foundation | Charged per square foot (rate not published) | Cassia County Administrative Fees schedule; additional fee required per lineal foot of foundation/cement when installed with a permanent foundation, per the Placement Permit Application. Contact Building Department at 208-878-7302 for the current per-square-foot rate. |
Agricultural Building Siting Permit
VerifiedRequired for agricultural buildings in unincorporated Cassia County before construction, in lieu of a standard building permit. Agricultural buildings (used exclusively for storage of farm equipment/machinery, hay/grain/horticultural products, or livestock/poultry shelter) are exempt from the adopted building codes under Title 11, Chapter 1, but the county still regulates and ensures compliance with road setbacks and utility easements via this siting permit (County Code 9-5-3 B). Does not exempt the applicant from state electrical/plumbing permit requirements.
Verified 2026-07-08 · Source
Requirements
- Structure must be used exclusively for: storage of equipment/machinery used in agriculture; storage of hay, grain, or other agricultural/horticultural products; or livestock/poultry shelter, building, or shade structure — not for human habitation, employment, or public use
- Affidavit of Application for an Agricultural Siting Permit, signed and notarized, filed with the Zoning and Building Department
- Site map required showing placement of proposed building and setback distances to public roads, property lines, and other structures (front, sides, rear)
- Highway District Access Permit number, if required, with proof of notification to the applicable Highway District
- Applicable Fire District notification
- Structure must comply with road setback (54 ft from road center) and interior lot line setback (10 ft for outbuildings) and cannot be built over utility easements
- Does not exempt the applicant from Idaho state requirements to obtain electrical or plumbing permits if applicable
Required documents
- RequiredAffidavit of Application for an Agricultural Siting Permit (2024)Notarized affidavit application; available at cassia.gov/county-forms-applications
- RequiredSite Map / Plot PlanShows building placement and setback distances to roads, property lines, and other structures; page 3 of the Affidavit form
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Agricultural Siting Permit fee | $75.00 | Printed on the Affidavit of Application for an Agricultural Siting Permit (2024), Office Use Only section |
Solar Photovoltaic (PV) Permit
VerifiedRequired for installation of rooftop or ground-mount solar photovoltaic systems in unincorporated Cassia County. No solar-specific fee line item is published; the structural/mounting portion is billed under the same square-footage/IBC 2003 Valuation Table 1 building permit fee used for general construction. Electrical, plumbing, and HVAC permits and inspections are handled entirely by the State of Idaho Department of Building Safety (part of DOPL), not the County.
Verified 2026-07-20 · Source
Requirements
- Building permit required for the structural/mounting portion of a solar PV installation, calculated based on square footage using the IBC 2003 Valuation Table 1, issued by Cassia County Zoning and Building Department per County Code 11-1-6
- The ELECTRICAL interconnection portion of a solar PV installation requires a SEPARATE permit from the Idaho Department of Building Safety (dbs.idaho.gov/permits), not Cassia County — per the County's own Permit Information page: 'For Electrical, Plumbing and HVAC Inspections & Permits Idaho Dept. of Building Safety online'
- Request for inspections must be given at least six (6) business hours in advance
- Non-refundable Residential Plan Review fee applies, credited toward the total building permit fee
Required documents
- RequiredCassia County Building Permit ApplicationStandard application for the structural/mounting portion
- RequiredIdaho Department of Building Safety Electrical PermitSeparate state-issued permit required for the electrical interconnection portion — obtained directly from dbs.idaho.gov/permits, not through the County
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building permit fee | Calculated based on square footage using the IBC 2003 Valuation Table 1 | Cassia County Administrative Fees schedule, Building Department section — no distinct solar line item published; fee amount authorized by Board of County Commissioners resolution per County Code 11-1-6 |
| Plan Review — Residential | $200.00 | Non-refundable, applied to total building permit fee; Cassia County Administrative Fees schedule |
| Re-inspection / not-ready-for-inspection fee | $30.00 per hour (1 hour minimum) | Charged if the project is not ready for inspection at the scheduled appointment time; Cassia County Building Permit Application (2025) |
EV Charger / EVSE Permit
VerifiedCassia County does not issue electrical permits at all — per the county's own Permit Information page, 'For Electrical, Plumbing and HVAC Inspections & Permits' applicants must use the Idaho Department of Building Safety (part of DOPL) online system, not the County. Installing a Level 2 or DC fast EV charger's dedicated circuit is therefore a state-issued Electrical Permit, not a county permit; a county Building Permit only applies if the installation involves new structural/mounting work (e.g., a new carport or accessory structure housing the charger). Re-verified 2026-07-20: re-confirmed cassia.gov/permit-information is live and directs applicants to the Idaho Department of Building Safety (dbs.idaho.gov/dopl.idaho.gov) for electrical permits/inspections rather than the county. Also independently re-pulled DOPL's current Homeowner Electrical Permit Application PDF (dopl.idaho.gov/wp-content/uploads/2023/11/ELE-Home-Owner-Electrical-Permit-Application.pdf, revised 8/17/2022) and confirmed its Electrical Permit Worksheet (Fee Schedule) still states the exact figure previously documented: 'Existing Residence... $65 fee plus $10 per additional branch circuit, up to the maximum of the corresponding sq. of the building (one circuit is included in the $65.00).' This is a real, current, statewide, citable governing figure, sufficient to upgrade this entry from partial to verified.
Verified 2026-07-20 · Source
Requirements
- The electrical circuit/service work for an EV charger requires a State of Idaho Electrical Permit from the Idaho Department of Building Safety (dbs.idaho.gov/permits) — Cassia County does not issue or inspect electrical permits
- A county Building Permit is required only if the EV charger installation is paired with new construction (e.g., a carport, garage, or accessory structure) subject to the 2018 IBC/IRC as adopted by Cassia County
- Homeowners self-installing on their own residence may use Idaho's Homeowners Electrical permit path; contractors must hold a valid Idaho electrical contractor license
- Installation must comply with the National Electrical Code edition currently adopted by the State of Idaho Electrical Board
Required documents
- RequiredIdaho Department of Building Safety Electrical PermitState-issued permit for the EV charger circuit/service work, obtained directly from dbs.idaho.gov/permits, not through Cassia County
- OptionalCassia County Building Permit ApplicationOnly required if the EV charger installation is paired with new structural/mounting construction reviewed by the County
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| State Electrical Permit — Existing Residence / Branch Circuit (homeowner) | $65.00 plus $10.00 per branch circuit | Idaho Department of Building Safety, 'Homeowners Electrical: How Do The Fees Work?' (dbs.idaho.gov/programs/electrical-program/homeowners-electrical-how-do-the-fees-work/) — this is the published state fee for a homeowner adding a branch circuit (such as a dedicated EV charger circuit) to an existing residence. Cassia County itself charges no fee for this work because it does not administer electrical permits; the applicable fee is set entirely by the State of Idaho, not the County. Fees for a licensed-contractor-pulled permit were not separately confirmed and may differ — contact Idaho DOPL/DBS directly at 1-800-955-3044 or 1-208-332-4700. |
| County Building Permit (only if paired with new structural/mounting construction) | Calculated based on square footage using the IBC 2003 Valuation Table 1 | Cassia County Administrative Fees schedule — applies only if the EV charger is installed with a new carport/garage/accessory structure requiring county building permit review; the charger circuit itself is never billed by the County. |
Sources & verification
Verified against official sources. Last reviewed 2026-07-08.
Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Unincorporated Cassia County building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.