Idaho building code plan review: the 2018 codes in IDAPA 24.39.30, the 2024 update that did not take effect, and DOPL, Fire Marshal, and local review

Which Idaho codes apply to a set of drawings?

Idaho Code §39-4109 adopts the International Building Code with its accessibility appendices, excluding its incorporated electrical, mechanical, fuel gas, plumbing, fire, and property maintenance codes other than referenced International Fire Code sections, the Idaho Residential Code (the IRC without the parts on energy, mechanical, fuel gas, plumbing, and electrical work), the 2018 Idaho Energy Conservation Code, and the International Existing Building Code, each as the Idaho Building Code Board adopts and amends it. An edition the Board adopts takes effect on January 1 of the following year, the Board may not lower accessibility below the ICC text, and it may not make the residential code more restrictive than the ICC text. Under §39-4103, buildings owned by a state agency must meet these codes and are subject to DOPL and the State Fire Marshal for plan review, permits, and inspections, with plans routed to the affected local governments, and buildings others own but build or renovate for a state agency must meet the state codes without limiting local permitting. Section 39-4116 covers everyone else: there is no population threshold, so a city or county enforces codes only if it already did or elects to by ordinance, and then must adopt the IBC, the Idaho Residential Code Parts I to III and IX, and the 2018 Idaho Energy Conservation Code by ordinance effective January 1 after the Board’s adoption. It may amend them for local concerns with at least equivalent protection, but not the accessibility provisions, and it may not adopt IRC or residential energy provisions the Board has not adopted; it may amend the residential code’s administrative part, definitions, Section R301, and appendices, and the rest of Part III only on a finding of good cause after a noticed public hearing. The same section exempts single-family homes and dwellings of up to two units from the sprinkler requirements of the IFC, IBC, and residential code, exempts agricultural buildings other than places of human habitation, processing, or public use, and governs a permit by the laws in effect when the application is received.

Subsection 600 of IDAPA 24.39.30 adopts the 2018 IBC with its accessibility appendices and Idaho amendments, the 2021 IBC provisions for mass timber Types IV-A, IV-B, and IV-C required by §39-4109A, the 2018 IRC Parts I, II, III, and IX for one- and two-family dwellings with amendments, the 2018 IEBC, and the commercial and residential provisions of the 2018 IECC with amendments. DOPL’s adopted codes list names the same codes and explains that the “2020 Edition” in the names Idaho Residential Code and Idaho Energy Conservation Code identifies the legislative session that adopted the amendments, not a code edition. The trade codes come from other boards: the 2015 Uniform Plumbing Code as the Idaho State Plumbing Code (IDAPA 24.39.20), the 2023 NEC with amendments (IDAPA 24.39.10), the 2018 IMC and IFGC on DOPL’s list, and the ASME A17 elevator codes in IDAPA 24.39.40. Idaho Code §41-253 adopts the 2000 International Fire Code and later editions the State Fire Marshal adopts, and the Fire Marshal’s Bulletin No. 20-14 adopted the 2018 IFC effective January 1, 2021 with Appendices B to F and a table of NFPA standard editions; the summary of IDAPA 18.08.01 still mentions only the 2000 edition, so confirm the fire code basis with the Fire Marshal. All checked November 4, 2026.

The 2024 codes are not adopted. The Board adopted the 2024 IBC, IRC, and IECC as pending rule Docket 24-3930-2502, which could take effect only if the 2026 Legislature approved it by concurrent resolution, and the House Business Committee minutes of February 17, 2026 record a motion to reject it that carried. The current rule still adopts the 2018 editions, and DOPL’s rules page says the boards are not engaged in rulemaking for 2026 to 2027 and existing rules remain in effect. One cross-reference in the rule is also out of date: the IBC amendment adding Section 602.1.2 points to paragraphs 004.01.b and 004.01.h, while the mass timber provisions now sit in subsection 600.02, so cite them by that subsection.

The Idaho amendments change what a reviewer looks for. The IBC amendments classify day care for twelve or fewer children and custodial or medical care for five or fewer persons within a dwelling as Group R-3 or allow them under the IRC, change two footnotes to IBC Table 2902.1 so that service sinks are not required in business occupancies other than restaurants and in mercantile occupancies with an occupant load of thirty or fewer, and drinking fountains are not required for an occupant load of thirty or fewer, and delete Section 3113 on relocatable buildings. The IRC amendments let small owner-occupied lodging houses and care facilities use the IRC, replace the exterior wall fire-resistance and opening table and the garage separation table, which calls for 5/8-inch Type X gypsum board, delete the fire protection of floors section and the dwelling sprinkler section, require whole-house mechanical ventilation, let townhouses omit sprinklers where two one-hour walls or a common two-hour wall separate the units, replace the footing tables with an Idaho table, and allow APA System Report SR-102 for wall bracing. The energy amendments exempt buildings conditioned only for equipment, certain accessory, sports practice, well, and sewer buildings, add an economizer exception for unusual outdoor air contaminants, change the residential insulation table for climate zones 5 and 6, add a log home envelope path, and accept a visual inspection in place of envelope tightness testing when the permit holder chooses it at application.

Plan review follows ownership and occupancy. DOPL’s FAQ says plans for state-owned buildings, buildings on state-owned land, and any building a state agency occupies, even under a lease, must be reviewed by DOPL and the State Fire Marshal, through a single submittal that DOPL forwards. For leased buildings, §39-4103(3) adds that local permitting is not limited, so expect the city or county to review as well and confirm the route with DOPL. The Fire Marshal’s Plans Review Section reviews state-owned and state-leased buildings for sprinklers, fire alarm, smoke detection and evacuation, and means of egress, with separate applications for sprinkler, fire alarm, clean agent, and hood systems. Under §39-4113, a school district has its public school plans approved by DOPL or by a city or county that has adopted all the applicable codes and uses plans examiners with the certifications the statute lists, though work valued at $100,000 or less may go to any local government; the review covers building, mechanical, fuel gas, plumbing, electrical, accessibility, elevators, boilers, and energy, the initial review must be done within 30 calendar days, and approved plans may not change materially without approval. The Uniform School Building Safety Code in IDAPA 24.39.60 bundles the Idaho building code, IMC, IFGC, ASME A17.1, IECC, ICC A117.1, IFC, NEC, and plumbing code for schools, and IDAPA 24.39.30 has a district that seeks the building replacement value calculation engage a commissioning agent who puts the commissioning requirements in the construction documents. Section 39-4111 requires a local permit where a city or county enforces codes and, subject to accessibility, bars a permit from requiring upgrades to unaffected existing parts that met the code when built unless a specific substantial safety hazard is identified. DOPL does not require plans for Group U buildings of conventional light-frame Type V construction, and it keeps in-plant jurisdiction over modular buildings while site work goes to the city or county. Permit routing is on the Idaho page, and the model codes have their own guides: IBC, IRC, IEBC, IECC, and IFC.

Gather the code analysis, the review route, and each discipline’s Idaho references

Collect the cover sheet and code analysis with every code and edition cited, the occupancy classification with any day care or care facility counts, the construction type, including any mass timber type, the life safety plans with rated assemblies, egress, sprinklers, and fire alarm, the site plan with fire apparatus access, hydrants, and fire flow under IFC Appendices B to D, the plumbing fixture count, structural general notes with the design loads, elevations, sections, and wall details, the mechanical, fuel gas, plumbing, and electrical drawings, the energy compliance documents, including the residential envelope tightness method, the accessibility plans and details, any commissioning requirements, and the specifications.

Add the owner and the occupant, including any state agency lease, the school district’s written election of reviewer and the project value, the city or county and whether it enforces codes, its local amendments, the date the permit application was or will be received, any modular components, the deferred submittals, and the State Fire Marshal applications for each fire protection system on a state project. Download IDAPA 24.39.30 and the trade rules from the DOPL rules page.

Trace the Idaho codes through the set

Fire code sheets continue in the IFC guide, sprinkler and alarm documents in the NFPA 13 and NFPA 72 guides and the fire sprinkler checklist, mass timber in the mass timber coordination checklist, plumbing in the UPC guide, mechanical and fuel gas sheets in the IMC and IFGC guides, electrical notes in the NFPA 70 guide, elevators in the ASME A17.1 guide, accessible details in the ICC A117.1 guide and the accessibility checklist, and the full set in the architectural drawing checklist. Neighboring state codes are in the Montana guide, the Utah guide, the Washington guide, and the Oregon structural code guide.

Example: a state agency lease in a new office building

Hypothetical example. A state agency signs a lease for the second floor of a new, privately owned two-story office building in an Idaho city with its own building department, and the tenant improvement drawings are adapted from a project the architect completed in another state. The code analysis cites the 2024 IBC and the 2021 IECC, the plumbing fixture schedule cites the International Plumbing Code, the cover sheet names the city as the only reviewing authority, and the fire alarm notes say the shop drawings go to the city fire department only.

The code analysis cites the 2024 IBC and the 2021 IECC, while IDAPA 24.39.30 adopts the 2018 editions; the Board’s 2024 update, pending rule Docket 24-3930-2502, was rejected by the House Business Committee on February 17, 2026 and is not in the current rule. The fixture schedule cites the International Plumbing Code, while Idaho uses the 2015 Uniform Plumbing Code as the Idaho State Plumbing Code and Idaho Code §39-4109 excludes the plumbing codes incorporated in the IBC. DOPL’s FAQ says plans for any building a state agency occupies, even under a lease, must be reviewed by DOPL and the State Fire Marshal, and the Fire Marshal’s Plans Review Section takes separate fire alarm applications for state-leased buildings, while the cover sheet names only the city. Confirm the code editions, the plumbing basis, and the review route.

The architect revises the code analysis to the 2018 codes with the Idaho amendments, the plumbing engineer moves the fixture schedule to the Idaho State Plumbing Code, and the team confirms with DOPL that the tenant improvement goes to DOPL and the State Fire Marshal in one submittal as well as to the city, with the fire alarm contractor filing the Fire Marshal’s application. The finding is a citation and routing conflict; DOPL, the State Fire Marshal, and the city decide compliance.

Review an Idaho set with Groundbook

Upload the current drawings and specifications to Groundbook, and state the edition, amendments, and review scope in your instructions. IDAPA 24.39.30 and the trade and fire rules are free on the Idaho Administrative Code site, the statutes on the Legislature’s site, and DOPL and the State Fire Marshal publish their adopted code lists and bulletins. Upload the Idaho rules and any local ordinance as code files, with the 2018 International Codes, the 2021 IBC mass timber provisions, the 2015 Uniform Plumbing Code, the 2023 NEC, and the NFPA standards in Bulletin 20-14 from copies you are licensed to use where the license permits uploading them. See how Groundbook works with local and licensed codes.

Compare the cover sheet, code analysis, life safety plans, and every discipline’s general notes with the architectural, accessibility, structural, plumbing, mechanical, fuel gas, electrical, fire protection, and energy documents. Flag citations to IBC, IRC, IEBC, or IECC editions other than 2018 except the 2021 IBC mass timber provisions the supplied rule adopts, plumbing notes that cite the IPC instead of the Idaho State Plumbing Code, electrical notes not on the 2023 NEC, care occupancies, exterior walls, garage separations, footings, and townhouse separations that do not match the supplied Idaho amendments, dwelling sprinkler requirements the supplied statute exempts, and a reviewing authority that does not fit the owner, occupant, or school district election in my instructions. Use the supplied Idaho rules and model codes and cite both sources.

Groundbook compares the set with reference documents you upload, including licensed codes and standards you hold, and links each potential finding to the note or sheet and to the Idaho rule, statute, or model code. It has no built-in library of licensed codes, runs no calculations, and does not design anything. It does not decide which agency reviews the plans, whether a local amendment is valid, or which fire code edition a fire official applies; each finding is a question for the responsible design professional.

Document review does not certify compliance, issue a permit or plan approval, or replace the design professional, DOPL, the State Fire Marshal, a school district’s elected reviewer, or the local building official.