Boise building permit requirements

Boise Planning and Development Services — Building Division

Verified 2026-06-29 · Source

9 permit types(208) 608-7070Mon–Fri 8:00 AM – 5:00 PM (closed holidays)

Department information

Address: 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)
Website: Official site

Codes adopted

Idaho adopts a statewide baseline building code set under the Idaho Building Code Act (Idaho Code Title 39, Chapter 41) and IDAPA rules administered by the Idaho Division of Occupational and Professional Licenses (DOPL). Effective January 1, 2021, the statewide baseline includes the 2018 International Building Code (IBC), 2020 Idaho Residential Code (based on the 2018 IRC Parts I–III and IX with Idaho amendments), 2020 Idaho Energy Conservation Code (based on the 2018 IECC with Idaho amendments), 2018 International Existing Building Code (IEBC), 2018 International Mechanical Code (IMC), 2018 International Fuel Gas Code (IFGC), and 2018 International Fire Code (IFC). The National Electrical Code is adopted separately by the Idaho Electrical Board (IDAPA 24.39.10), not bundled with the building code: Idaho enforces the 2023 NEC, effective July 1, 2024 (the state used the 2017 NEC with amendments before that and skipped the 2020 edition). Local jurisdictions must enforce the state baseline and may adopt amendments only where those amendments are at least as stringent as the state-adopted editions; local amendments may not be less restrictive. Enforcement is local — each city or county issues permits and performs inspections. Always confirm the current adopted edition and any local amendments with your specific jurisdiction before submitting plans.

2018 International Building Code (IBC) — with Appendices H (Signs) and J (Grading); Mass Timber provisions only of the 2021 IBC2018 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, 20242018 International Fire Code (IFC) — with Appendices B, C, D, F and L; 2019 NFPA 13; 2019 NFPA 722018 International Mechanical Code (IMC) — commercial and residential projects with 3+ units2018 International Fuel Gas Code (IFGC) — commercial and residential projects with 3+ units2018 IRC Parts V and VI — single- and two-family residential mechanical and fuel gas

Permit types

Residential Building Permit (New Construction)

Required for all new single-family dwellings, duplexes, and townhouses in Boise. Covers structural construction, framing, envelope, and all associated systems.

Residential Addition / Alteration Permit

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.

Residential Electrical Permit

Required for electrical work in existing single-family dwellings and duplexes in Boise, including panel upgrades, new circuits, wiring for additions, and service changes. All work must comply with the 2023 NEC (effective April 26, 2024).

Residential Plumbing Permit

Required for plumbing installations, alterations, and repairs in Boise, including water heater replacements, fixture additions, re-piping, and sewer/water service line work. Governed by the 2017 Idaho State Plumbing Code (based on the 2015 UPC).

Residential Mechanical / HVAC Permit

Required for heating, ventilation, air conditioning, fuel gas, and related mechanical installations in Boise single-family dwellings and duplexes. Covers furnaces, A/C, heat pumps, ductwork, gas fireplaces, gas piping, dryer vents, range hoods, and bath exhaust fans.

Residential Roofing Permit

Required for roof replacement, re-roofing, siding replacement, and window replacement in Boise. Permit type 428 covers all three categories.

Solar Photovoltaic (PV) Permit

Required for installation of rooftop or ground-mounted solar photovoltaic systems on residential properties in Boise. Requires both a building permit for structural mounting (flat $165 fee) and a separate electrical permit for wiring ($110 for the electrical portion on existing residences).

Accessory Dwelling Unit (ADU) Permit

Required for construction of a new accessory dwelling unit on a residential property in Boise, including detached cottages, attached additions, and internal conversions. Boise offers a Pre-Approved ADU program (permit type 402-B) with pre-reviewed plan sets to expedite permitting.

Water Heater Permit

Required for water heater installation or replacement in Boise, issued as a Residential Plumbing Permit (420). A water heater is a single-fixture installation per the Boise Plumbing Code Fee Schedule.

Tips & gotchas

Boise uses the 2017 Idaho State Plumbing Code (based on the 2015 Uniform Plumbing Code) — not the International Plumbing Code. Rules differ, especially for fixture counts and fees.
Gas piping, boilers, hydronic heating, and solar thermal systems are Mechanical Permits (422) in Boise — not Plumbing Permits.
Idaho state law allows homeowners to pull their own electrical and plumbing permits for their primary or secondary residence — a licensed contractor is not required for the permit, though the work must still pass inspection.
A Preliminary Conference inspection is mandatory for homeowners pulling their own electrical permit (424) in Boise.
Boise requires a separate electrical permit for solar PV wiring in addition to the building permit for structural mounting — two permits total for every solar installation.
Frost depth is 24 inches minimum in Boise — all footings (decks, retaining walls, new construction) must extend below this depth.
Decks more than 12 inches above grade require a permit. Decks 30 inches or more above grade require guardrails per IRC.
Fences exceeding 7 feet in height require a building permit in Boise.
Retaining walls more than 4 feet tall require a permit.
City Approved Plans must be on site during all inspections.
Schedule inspections by calling (208) 608-7070 before 7:30 a.m. for same-day scheduling.

Sources & verification

Verified against official sources. Last reviewed 2026-06-29.

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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