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Residential Addition / Alteration Permit in Boise, Idaho

Required for additions, structural alterations, remodels, basement finishes, decks over 12 inches above grade, retaining walls over 4 feet, and other residential alterations in Boise.

Verified 2026-07-16 · Source

When you need this permit

  • Room additions and structural modifications
  • Decks more than 12 inches above grade
  • Retaining walls more than 4 feet in height (or a 2-foot retaining wall with a slope/surcharge, which also requires engineering)
  • Basement finishes involving framing, electrical, plumbing, or mechanical work
  • Detached accessory structures exceeding 200 square feet
  • Fences exceeding 7 feet in height

Required documents

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Fee schedule

Building Permit — valuation-based per Table 1-ABoise Building Code Fee Schedule, Table 1-A
Same valuation table as new construction: $26.37 + $2.95/$100 (up to $2,000); $70.76 + $12.71/$1,000 ($2,001–$25,000); $362.80 + $9.30/$1,000 ($25,001–$50,000); etc.
Residential Plan ReviewPer Boise Building Code Fee Schedule item 9
20% of the building permit fee
Reinspection Fee
$55 per occurrence

Review timeline

Plan reviewBoise’s published plan-review target
1–28 business days

How long did your Residential Addition / Alteration Permit permit actually take in Boise?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

  1. 1

    Framing / Structural

    After framing is complete and before walls are covered — verify structure, connections, and blocking

  2. 2

    MEP Rough-In

    Electrical, plumbing, and mechanical rough-ins before wall cover — may be separate trade permits

  3. 3

    Insulation

    Insulation installed, vapor barrier in place — before drywall

  4. 4

    Final

    All work complete per approved plans

See the full Boise inspection guide — scheduling & re-inspection fees →

Tips

  • Boise PDS recommends homeowners meet with a plan reviewer in person to submit addition/alteration plans — appointments available.
  • Decks more than 12 inches above grade require a permit; decks 30 inches or more above grade require guardrails per the 2018 IRC.
  • Retaining walls more than 4 feet tall (measured from bottom of footing to top of wall) require a permit — per the Homeowner's Guide, a 2-foot retaining wall with a slope or surcharge also requires a permit and engineering.
  • Fences exceeding 7 feet in height require a permit in Boise per the Homeowner's Guide.
  • Basement finishes need to address egress windows in bedrooms and combustion air for fuel-burning appliances.

Frequently asked questions

Yes. Any basement finish involving framing, electrical, plumbing, or mechanical work requires a building permit (406) plus trade sub-permits as applicable.

In Boise, the published Building Permit — valuation-based per Table 1-A is: Same valuation table as new construction: $26.37 + $2.95/$100 (up to $2,000); $70.76 + $12.71/$1,000 ($2,001–$25,000); $362.80 + $9.30/$1,000 ($25,001–$50,000); etc.. Additional published fees: Residential Plan Review — 20% of the building permit fee; Reinspection Fee — $55 per occurrence. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Per Boise's April–June 2026 timeframe report, Level 1 additions/alterations average 1 business day for first review. Level 2 projects average 8 business days (target: under 10 days). Ready-to-issue time averages 11–28 days depending on level.

You'll need: Permit Application (Form 406); Submittal Checklist; Construction Drawings. Depending on your project, Boise may also ask for: Energy Code Compliance Form; Contractor Registration Declaration Form; Residential Photovoltaic Systems Checklist. See the required-documents checklist on this page for details on each.

Boise requires 4 inspection(s) for a residential addition / alteration permit, in order: Framing / Structural, MEP Rough-In, Insulation, Final. Schedule each through Boise Planning and Development Services — Building Division ((208) 608-7070).

Apply through Boise Planning and Development Services — Building Division at 150 N Capitol Blvd, Boise, ID 83702. Phone: (208) 608-7070, email: permits@cityofboise.org. Office hours: Mon–Fri 8:00 AM – 5:00 PM (closed holidays). Official information: https://www.cityofboise.org/departments/planning-and-development-services/building/.

Boise, Idaho has adopted: 2018 International Building Code (IBC) — with Appendices H (Signs) and J (Grading); Mass Timber provisions only of the 2021 IBC; 2018 International Existing Building Code (IEBC); 2018 International Residential Code (IRC), Parts I–IV and IX — with Appendices Q (Tiny Houses) and S (Strawbale Construction); 2018 International Energy Conservation Code (IECC); 2017 Idaho State Plumbing Code (based on the 2015 Uniform Plumbing Code, including Chapter 13 – Medical Gas); 2023 National Electrical Code (NEC) — effective April 26, 2024; 2018 International Fire Code (IFC) — with Appendices B, C, D, F and L; 2019 NFPA 13; 2019 NFPA 72; 2018 International Mechanical Code (IMC) — commercial and residential projects with 3+ units; 2018 International Fuel Gas Code (IFGC) — commercial and residential projects with 3+ units; 2018 IRC Parts V and VI — single- and two-family residential mechanical and fuel gas. Local amendments apply — see the Boise overview page for the full list.

Yes, if the deck is more than 12 inches above grade. Apply for a Residential Addition/Alteration (406) permit online at permits.cityofboise.org or in person.

Sources & verification

Verified against official sources. Last reviewed 2026-07-16.

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 Boise building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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Residential Addition / Alteration Permit in other cities

Caldwell, IdahoMeridian, IdahoNampa, IdahoAlamogordo, New MexicoAlbuquerque, New MexicoArtesia, New MexicoCarlsbad, New MexicoClovis, New Mexico

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