County Guide · Verified 2026

ADU Construction Permits in Bonneville County, Idaho

Permit required

Check local building codes, estimate your municipal fees, and review inspection requirements for 2026.

Local Project Overview

ADU Construction · Bonneville County, Idaho

Permit required

In Idaho, a ADU Construction requires a building permit.

An accessory dwelling unit (ADU) always requires a building permit because it adds a habitable dwelling, including electrical, plumbing, mechanical permits and egress/zoning review. Plans are reviewed under the Statewide code (IRC 2024); apply through Bonneville County Zoning & Building before work begins.

Source: Statewide, IRC 2024 · Verified 2026 by StateDataIndex

Building an Accessory Dwelling Unit requires complex zoning, structural, and utility permits.

With a population of around 129,523 residents, Bonneville County generally runs a more streamlined permitting process than major urban hubs.

Code Compliance & Inspections

Because of severe winter weather in Idaho, any exterior structures or footings must be set below the local frost line to prevent shifting, as mandated by the Idaho State Building Code.

Concurrent Permits & HOAs

For Bonneville County residents, we recommend reviewing your neighborhood HOA covenants before paying any municipal fees. Homeowners associations often maintain stricter rules regarding materials and dimensions for your ADU Construction than the county itself.

Zoning & Cost Factors

Idaho generally favors property rights with relaxed state-level oversight, meaning agricultural zoning often dominates outside of major hubs like Boise. Fortunately, Idaho maintains relatively builder-friendly regulations, keeping base permit fees competitive.

Permit fees in Bonneville County

Permit fees vary by jurisdiction and by your project's valuation, so there is no single fixed figure for Bonneville County. We only publish fees confirmed by real homeowners — none have been reported here yet.

Confirm the current fee directly with Bonneville County Zoning & Building ((208) 524-7920). If you have paid for a permit here, you can add it here to help others.

Bonneville County Building Department

Office: Bonneville County Zoning & Building

Address: 357 Constitution Way, Idaho Falls, ID 83402, USA

Phone: (208) 524-7920

Source: official Bonneville County government records. Hours and procedures can change — call ahead to confirm.

How to Apply in Bonneville County

In Bonneville County, you can begin your application online through the county's permit portal, or submit blueprints and a property survey in person. Including your contractor's Idaho Division of Occupational and Professional Licenses license number helps avoid rejections.

ADU Construction Requirements in Bonneville County

Typical Submittal Package

When applying for a ADU Construction permit, you or your contractor will generally need to submit the following documentation for the city's review:

  • Comprehensive architectural and structural plans
  • Foundation engineering reports
  • Sewer, water, and utility connection plans
  • Site plan showing property lines and setbacks

Standard Ordinances & Processing Time

Key code points for a ADU Construction in Bonneville County: ADUs typically have maximum square footage limits (often 800-1200 sq ft), height restrictions, and usually require dedicated off-street parking depending on local zoning.

Typical processing time: a few days to several weeks, depending on current workload and the season. Contact Bonneville County Zoning & Building for a current estimate.

Frequently Asked Questions

What happens if I build a ADU Construction without a permit in Bonneville County?

Building without authorization is considered a code violation. The local government can issue a Stop Work Order, forcing you to halt construction immediately. You may be subject to retroactive permit fees (often double the original cost), daily fines, or even a mandate to tear down the unpermitted work at your own expense.

Can a homeowner pull their own ADU Construction permit in Idaho?

Yes. Idaho generally allows property owners to act as their own general contractor under an Owner-Builder exemption. If you take this route, you assume full legal and financial liability and must ensure all work complies with the Idaho State Building Code.

How much does a ADU Construction permit cost in Bonneville County?

Permit fees vary by jurisdiction and by your project's valuation, so Bonneville County does not publish a single fixed figure. Confirm the exact fee with the local building department before applying.

How long does it take to get a ADU Construction permit in Bonneville County?

Processing time in Bonneville County varies by season and current application volume at the building department; contact Bonneville County Zoning & Building for a current estimate.

Where do I apply for a ADU Construction permit in Bonneville County?

You can apply through the Bonneville County Zoning & Building or online via the county permit portal. For questions, call (208) 524-7920.

Help the Bonneville County Community

Did you recently pay for a permit here? Anonymously share the fee to help our database stay accurate.

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Nearby Jurisdictions in Idaho

Building near the county line? Check requirements for neighboring areas:

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