Published
The Idaho Building Code Act: the state chapter behind every permit in St. Anthony
The chapter with its name on it
Every permit in this state traces back to one chapter of Idaho law, and it introduces itself plainly:
“This chapter shall be known as “The Idaho Building Code Act.””
— Idaho Code section 39-4102, Short title. Retrieved 5 October 2026
Title 39, chapter 41 of the Idaho Code is short as statutes go — a few dozen sections — but it decides who inspects your framing, which code book your plans are judged against, what a city may add on top, how a failed inspection can be re-checked, and where you go when you disagree. This page maps it section by section, with the parts a St. Anthony builder actually touches.
The map
| Section | What it does |
|---|---|
| 39-4102 | Names the chapter |
| 39-4104 | Splits enforcement: state division for state work, local governments for theirs |
| 39-4106 | Creates the ten-member Idaho building code board |
| 39-4108 | Requires ICC certification for government inspectors |
| 39-4109A | Ordered mass timber types into the code by January 1, 2022 |
| 39-4109B | Bans EV-infrastructure mandates in building plans (2025) |
| 39-4111 | Requires permits; caps what they can force you to upgrade |
| 39-4116 | Governs how local governments adopt and enforce the codes |
| 39-4119 | Authorizes live virtual re-inspections, with a hard structural limit |
| 39-4120 | Sends appeals to the board on a twenty-day clock |
Who enforces, who decides
The chapter’s enforcement split runs in two sentences: the administrator of the division of occupational and professional licenses enforces the provisions that apply to the state, while local governments that adopt building codes enforce the provisions that govern their application. St. Anthony’s place in that split is the two-code-book structure we have mapped before — and the question of which office holds your application starts with where your lot actually sits.
Above the enforcement layer sits the Idaho building code board — an appeals, code-adoption, and rulemaking body of ten governor-appointed members, four-year terms, with removal for three consecutive unexcused absences. Its composition is written to force every constituency into the room:
- One member of the general public
- One local fire official
- One licensed engineer and one licensed architect
- Two local building officials — one from a county, one from a city
- Two building contractors — one residential, one commercial
- One representative of the modular building industry
- One individual with a disability, from an organization representing people with disabilities
The person holding the clipboard
Since July 1, 2002, state and local government building inspectors must hold a valid certification as a building inspector or building plans examiner issued by the International Code Council (ICC). The statute then draws the fine lines a builder can be glad exist:
- An inspector holding only the residential certification may inspect only structures regulated by the International Residential Code.
- Working under the supervision of a fully certified inspector or plans examiner, that residential-certified inspector may inspect all occupancy classifications for up to three years.
- An inspector may be hired uncertified, but must obtain certification within up to six months — supervised until then, and no official adverse action may be taken without review and approval by a certified inspector or plans examiner in the meantime.
What the board has adopted
Two adoption orders in the chapter touch modern construction directly. Mass timber: by January 1, 2022, the board was directed to amend the code to include the 2021 International Building Code’s mass timber provisions — permitting construction types IV-A, IV-B, and IV-C with their heights and fire-safety features. Electric vehicles: in 2025, the Legislature itself stepped in with section 39-4109B, barring any state or local requirement that a building plan include EV charging infrastructure — the statute we unpacked in can they make you wire for EV charging?
What a permit may demand — and may not
Section 39-4111 is the chapter’s workhorse: work without a permit is unlawful, and the section’s subsection (3) then draws the boundary we devoted a page to — no forced upgrades of unaffected, code-compliant existing parts, hazard findings excepted, with the burden of proof on the government. If you remember one pairing from this chapter, make it that one: mandatory permit, bounded permit.
City hall’s side of the bargain
Section 39-4116 governs local adoption, and three of its clauses matter to a builder here:
- Cities can buy enforcement. Local governments “may contract with a public or private entity to administer their building code enforcement program” — the reason the name on your inspection report is not always the name on city letterhead.
- Adoption runs on a January cycle. Local governments adopt the board’s codes by ordinance effective January 1 of the year after board adoption — which is how the edition question gets its answer, and why local energy add-ons are mostly off the table (see the energy-code preemption).
- The adopted bundle is specific: the International Building Code with rules providing equivalency with the Americans with Disabilities Act accessibility guidelines and the federal Fair Housing Act accessibility guidelines, the Idaho residential code’s parts I–III and IX, and the energy conservation code — and local governments may not adopt parts of the IRC or the residential energy provisions the state board has not adopted. Single-family homes and duplexes are exempt from automatic fire sprinkler requirements, a subject with its own history in the Idaho amendments.
Re-inspection by video, with one hard wall
Section 39-4119 — added in 2025 and amended and renumbered in 2026 — authorizes the division and local governments to perform live virtual re-inspections at their discretion: an inspector using real-time video to re-check work without standing on the site. The walls around it are explicit. Each re-inspection must verify the address or physical location of the job. And the line that will matter on a big project: “Neither the division nor local governments shall use live virtual re-inspections for structural inspections on buildings that are three (3) stories or greater.” The statute’s own definitions draw a further circle — a re-inspection, by definition, follows a previous in-person inspection by the same enforcement side, so the first structural look is always on the ground.
When you disagree
The chapter’s last stop is the appeal:
“The board shall, within twenty (20) days after receipt of notice for an appeal, hear such appeals brought before it by persons affected by any code, rule, regulation or decision applicable to buildings within the jurisdiction of the division.”
— Idaho Code section 39-4120, Appeals to board - Judicial review. Retrieved 5 October 2026
Final board decisions, other than code interpretations, are subject to judicial review under the state’s administrative procedure act. Twenty days is a short fuse — and it pairs with the application-side clocks in the two-clocks rule and the ten-business-day review deadline: the law that limits how long they can sit on your application also limits how long you can sit on your objection.
A builder’s reading order
- Locate the lot — city or county decides the counter, and the area of city impact decides the planning horizon.
- Fix the edition — which code applies today is a lookup, not a guess.
- Sequence the permits — zoning first, then building; watch both clocks.
- Know the boundaries — no forced upgrades of untouched compliant work, no EV mandates, no local energy add-ons.
- If it goes sideways, move fast — the board’s twenty-day appeal window does not wait. Bring the paperwork here first: (208) 656-1745.
Common questions
What is the Idaho Building Code Act?
The name Idaho Code Title 39, chapter 41 gives itself in section 39-4102: 'This chapter shall be known as "The Idaho Building Code Act."' It is the state statute behind building permits - covering enforcement, the state code board, inspector certification, local adoption of codes, re-inspection methods, and appeals.
Who enforces the building code in Idaho?
Section 39-4104 splits it: the administrator of the division of occupational and professional licenses enforces the provisions that apply to the state, and local governments that adopt building codes enforce all the provisions governing application by local governments. Which office holds your permit depends on where the project sits.
Who sits on the Idaho building code board?
Ten governor-appointed members with four-year terms: one member of the general public, one local fire official, one licensed engineer, one licensed architect, two local building officials (one county, one city), two building contractors (one residential, one commercial), one modular industry representative, and one individual with a disability from a representing organization. Three consecutive unexcused absences is cause for removal.
Are Idaho building inspectors certified?
Yes. Since after July 1, 2002, state and local government building inspectors must hold a valid ICC certification as a building inspector or building plans examiner. A residential-only certification limits the holder to IRC-regulated structures; a three-year supervised window and a six-month post-hire certification path are written into section 39-4108.
Did Idaho adopt mass timber construction rules?
Yes. Section 39-4109A directed the board to amend the code by January 1, 2022 to include the 2021 International Building Code's mass timber provisions - permitting the three new construction types IV-A, IV-B, and IV-C along with their maximum heights and fire safety features.
Can a city hire a private company to run its building department?
Yes. Section 39-4116(1) states that local governments may contract with a public or private entity to administer their building code enforcement program. The name on an inspection report is not always the name on city letterhead.
Which building codes must Idaho local governments adopt?
Per section 39-4116(2), governments that issue building permits adopt by ordinance the International Building Code including rules providing ADA and federal Fair Housing Act accessibility equivalency, the Idaho residential code parts I-III and IX, and the energy conservation code - effective January 1 of the year after board adoption. They may not adopt unadopted parts of the IRC or residential energy provisions.
Are single-family homes required to have fire sprinklers in Idaho?
No. Section 39-4116(3) exempts single-family homes and multiple-family dwellings up to two units from code provisions requiring automatic fire sprinkler systems, while nothing prevents voluntary installation. The Idaho amendments behind this have their own history on our code-editions page.
Can building re-inspections be done by video in Idaho?
Yes, with limits. Section 39-4119 authorizes live virtual re-inspections at the enforcing authority's discretion, requires address or location verification for each one, and flatly prohibits live virtual re-inspections for structural inspections on buildings three stories or greater. The section was added in 2025 and amended and renumbered in 2026.
How do I appeal a building code decision in Idaho?
Section 39-4120 requires the board to hear appeals within twenty days after receipt of notice, brought by persons affected by any code, rule, regulation or decision applicable to buildings within the division's jurisdiction. Final decisions other than code interpretations are subject to judicial review under the administrative procedure act.
Can a local government require EV charging or force whole-building upgrades?
No to both. Section 39-4109B (added 2025) bars any EV-charging infrastructure requirement in building plans, superseding contrary local ordinances, and section 39-4111(3) blocks permit-driven upgrades of unaffected existing parts that complied with the code when built - unless the enforcing jurisdiction proves a specific substantial safety hazard.