County Building Permits

Ada County, ID - 2026 Building Permit Guide

How to apply for a building permit in unincorporated Ada County, Idaho. Permit authority, application steps, fees, and inspection requirements.

Idaho Updated March 2026

Permit Authority

Covers unincorporated areas of Ada County only. Residents within any incorporated city must use that city's permit authority.

Department
Ada County Development Services — Building Division
Address
Ada County Courthouse, Second Floor, 200 W. Front St., Boise, ID 83702
Phone
(208) 287-7900
Website
https://adacounty.id.gov/developmentservices/building-division/

Online Permit Portal

Open COBRA (Client Online Business Records Access)

Platform: COBRA • Account required: Yes • Submission: Online only

Additional resources:

Application Process

  1. Determine that the project address is in unincorporated Ada County (not within any city limits).
  2. Prepare required documents: completed building permit application, site plan, and construction drawings.
  3. Submit application online through the COBRA portal or in person at the Ada County Courthouse, Second Floor.
  4. The Permitting Team reviews the application for completeness and contacts you for payment.
  5. Pay via e-check or credit card; your application officially enters the review queue after payment.
  6. Building Division reviews plans for compliance with Ada County Building Code.
  7. Permit is issued when plans are approved.
  8. Post permit card on site and schedule inspections at required stages.
  9. Complete all required inspections and final permit closeout.

Typical processing time: Not published; contact department for current turnaround times.

Source: Ada County Development Services — Building Division

General Requirements

New construction, additions, structural alterations, demolition, relocations, and most improvements to structures in unincorporated Ada County.

Required Documents

  • Completed building permit application
  • Site plan showing property lines and structure locations
  • Construction drawings
Permit validity
Work must commence or resume within 180 days; permit is invalid if work does not commence within that period. Extensions require contacting the department before expiration.
Building code
2018 International Building Code (IBC), 2018 International Residential Code (IRC), 2018 International Energy Conservation Code (IECC), 2017 Idaho State Plumbing Code, 2018 International Mechanical Code, 2018 International Fuel Gas Code, 2018 International Urban-Wildland Interface Code, and the National Electrical Code (updated November 2025)
Owner-builder
Homeowners may pull permits on their primary residence if they perform the work themselves.
Contractor requirements
Licensed contractors must hold a current, valid State of Idaho contractor license.

Fees

Permit fee formula
Valuation-based; fees set per Ada County fee schedule (updated November 2025; contact department for details)
Payment note
E-check accepted ($3.00 flat fee); credit card accepted (2.4% convenience fee, minimum $2.00). Payment required before application enters review.

Fees change. Verify current amounts at the official fee schedule (effective November 2025).

Work That Does NOT Require a Permit

  • One-story detached accessory structures (tool sheds, playhouses, similar) with floor area not exceeding 200 sq. ft.
  • Fences not over 6 feet high (subject to zoning setback requirements; no permit required but zoning standards still apply)
  • Decks not more than 30 inches above grade at any point that do not serve as an exit
  • Painting, flooring, cabinets, countertops, and wall coverings (interior cosmetic work)
  • Agricultural buildings meeting IBC definition of 'Ag Buildings' (must still comply with zoning setbacks)
  • Concrete slabs

Important: MEP (mechanical, electrical, plumbing) permits are handled separately; contact Idaho DBS for trade permit exemptions.

Inspections

How to Schedule

Scheduling deadline
Inspections must be requested the business day before, by 4:30 PM via phone or by midnight via the portal/email.
Inspection hours
Monday-Friday (weekend inspections not available)

Typical inspection sequence: Typical sequence: footing/foundation, framing, rough mechanical/electrical/plumbing (as applicable), insulation, final inspection.

Additional Resources

Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Ada County Development Services — Building Division before applying.

Frequently Asked Questions

Ada County Building Permit FAQ

Do I need a building permit in unincorporated Ada County, ID?
New construction, additions, structural alterations, demolition, relocations, and most improvements to structures in unincorporated Ada County.
How much does a building permit cost in unincorporated Ada County, ID?
Fees are calculated as: Valuation-based; fees set per Ada County fee schedule (updated November 2025; contact department for details).
How do I apply for a building permit in unincorporated Ada County, ID?
1. Determine that the project address is in unincorporated Ada County (not within any city limits). 2. Prepare required documents: completed building permit application, site plan, and construction drawings. 3. Submit application online through the COBRA portal or in person at the Ada County Courthouse, Second Floor. 4. The Permitting Team reviews the application for completeness and contacts you for payment. 5. Pay via e-check or credit card; your application officially enters the review queue after payment. 6. Building Division reviews plans for compliance with Ada County Building Code. 7. Permit is issued when plans are approved. 8. Post permit card on site and schedule inspections at required stages. 9. Complete all required inspections and final permit closeout.
How long does it take to get a building permit in unincorporated Ada County, ID?
Typical processing time is Not published; contact department for current turnaround times..
What work is exempt from building permits in unincorporated Ada County, ID?
The following work is generally exempt: One-story detached accessory structures (tool sheds, playhouses, similar) with floor area not exceeding 200 sq. ft.; Fences not over 6 feet high (subject to zoning setback requirements; no permit required but zoning standards still apply); Decks not more than 30 inches above grade at any point that do not serve as an exit; Painting, flooring, cabinets, countertops, and wall coverings (interior cosmetic work); Agricultural buildings meeting IBC definition of 'Ag Buildings' (must still comply with zoning setbacks); Concrete slabs. Note: MEP (mechanical, electrical, plumbing) permits are handled separately; contact Idaho DBS for trade permit exemptions.
How do I schedule a building inspection in unincorporated Ada County, ID?
Inspections can be scheduled via: (208) 287-7900, COBRA portal inspection request page. Inspections must be requested the business day before, by 4:30 PM via phone or by midnight via the portal/email..

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Important: This page is an educational resource provided by jaspector.com. It is not legal advice, and it does not substitute for official guidance from the permit authority listed above. Permit requirements, fees, and processes change frequently. Always verify current requirements directly with the issuing department before beginning any construction project. Use of this page does not create an attorney-client relationship. Jaspector assumes no liability for any outcomes arising from reliance on this information.
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