Idaho: contractors register, but no state license tests them. Here's what that means.

Correlation verdict: Idaho CONFIRMS the license⇄disclosure inverse correlation — a soft-but-clean confirm — nudging the West from its 4-4 coin flip toward the confirm side. The licensing axis could hardly be weaker: registration with no exam, no bond, nothing but an insurance certificate — and Idaho uniquely outlawed the local workaround (§ 54-5213), so unlike NY or IL there is no city regime to route trust through; the state is uniformly credential-free for chimney work. And exactly as the inverse rule predicts, the sale side is where Idaho shows up: a mandatory statutory disclosure form that names "fireplace/wood stove," runs on a 10-day clock, and hands the buyer a genuine 3-business-day rescission right (§ 55-2515). The honest grading: the disclosure is mid-strength — the chimney lives in a parenthetical appliance list, not a named line item, and the remedy is actual damages only — so Idaho is a moderate confirm, not a poster child like PA. On the West's orthogonal wildfire/cap-law axis, Idaho sits on it twice, but locally rather than statewide: the fire half is municipal (Boise's WUI spark-arrestor ordinance, scattered IWUIC adoptions, no statewide WUI code), and Idaho adds the axis's other pole that most western states underweight — the inversion airshed regime, where entire towns (Pinehurst, the Cache Valley towns, the panhandle curtailment communities) have had their wood heat federally case-managed. Message for the page: in Idaho, "registered" means insured, not qualified — verify the DOPL registration (it's what makes the contractor sueable and lienable), then demand individual certifications, because no Idaho government will ever have tested them; at sale, read the disclosure but treat "fireplace/wood stove: functioning properly" as a checkbox, not an inspection.

Hypothesis confirmed: Idaho has contractor REGISTRATION, not a license — no exam, no competency test, no bond. STATE LAW: the Idaho Contractor Registration Act, Idaho Code § 54-5201 et seq. (Title 54, ch. 52, enacted 2005, registration mandatory since Jan 1, 2006; full chapter text verified at legislature.idaho.gov/statutesrules/idstat/title54/t54ch52/, checked Jul 10, 2026). "Construction" is defined broadly — "building, altering, repairing, adding to … improving, reconstructing … any building … or other structure" (§ 54-5203(2)) — chimney rebuilds, crowns, relines, and repairs are squarely inside. Administered by the Idaho Contractors Board under the Division of Occupational and Professional Licenses (DOPL) (§ 54-5206). What registration attests (§ 54-5210): an application under oath, proof of a $300,000 single-limit general liability policy, worker's comp proof (or an exemption statement), ownership disclosure, and a prior-revocation statement. That's the entire bar — no exam, no experience requirement, no surety bond. Fee capped by statute at $150/year; the Contractors Board rule currently sets $60 for application and for renewal (IDAPA 24.21.01 fee table, notation 7-1-26; files.dfm.idaho.gov/dfm-admin-website/rules/current/24/242101.pdf, checked Sep 25, 2026). Threshold: exemption for "casual, minor, or inconsequential" work where the aggregate contract price (labor + materials) is under $2,000, with an anti-splitting clause (§ 54-5205(2)(f); text re-read Sep 15, 2026) — so most real chimney jobs require registration, but a cheap sweep-only visit may not. Specialty trades are the real licenses: electrical (Title 54, ch. 10, "Electrical Contractors and Journeymen"), plumbing (ch. 26), and HVAC (ch. 50, "Installation of Heating, Ventilation and Air Conditioning Systems") are exam-based DOPL licenses, and licensees are exempt from registration (§ 54-5205(1)) — gas fireplace/insert and freestanding stove installs touch the HVAC license (see § 5). Penalties with real teeth: unregistered contracting is a misdemeanor (up to $1,000 fine / 6 months jail, § 54-5217(1)); an unregistered contractor cannot bring or maintain any action to collect payment (§ 54-5217(2)) and conclusively waives all mechanic's lien rights (§ 54-5208); building permits require presentment of the registration number (§ 54-5209). The oddball: § 54-5213(1) — since Jan 1, 2007, no Idaho city or county may run its own contractor registration or licensure program. Idaho preempted local licensing while declining to license at the state level — there is structurally nowhere in Idaho where a chimney contractor takes a competency exam. Public lookup: edopl.idaho.gov/OnlineServices/?link=PubSearch ("Search for a License or Registration," linked from the dopl.idaho.gov homepage; checked Sep 15, 2026).

Idaho registration attests to insurance and identity — literally nothing about skill. There is no exam of any kind (Michigan tests codes and business law; Nevada tests trade knowledge; Idaho tests whether your liability policy exists). A registered contractor has never been asked a single question about flues, clearances, crowns, or NFPA 211 — and because § 54-5213 bans local licensing, no Idaho jurisdiction can raise that bar. The HVAC/plumbing/electrical licenses do involve exams, but those test the mechanical trade, not chimney diagnosis; a masonry chimney contractor holds none of them. Individual certs (NCSG CCP/CCR; CSIA CCS, C-DET) plus an independent inspection are the only competence signal available anywhere in the state.

STATE LAW: the Idaho Property Condition Disclosure Act, Idaho Code § 55-2501 et seq. (1994; full chapter text verified at legislature.idaho.gov/wp-content/uploads/statutesrules/idstat/Title55/T55CH25.pdf, checked Jul 10, 2026). Sellers of residential property of 1–4 dwelling units — including nonowner-occupied rentals — must complete the statutory disclosure form (§ 55-2504). The statutory form (§ 55-2508) lists "fireplace/wood stove" — but only as one example inside item 4's parenthetical appliance list ("All appliances and service systems included in the sale … are functioning properly except: (please list and explain)"; the same parenthetical also names "smoke detectors"), alongside item 5's "Heating" line. There is no dedicated chimney/flue line item, and no carbon-monoxide item — weaker than Nevada's named "Fireplace & chimney" row or Michigan's checklist. Mechanics: delivery within 10 days of offer acceptance (§ 55-2509); the buyer may rescind within 3 business days of receiving the form, based on a specific objection to a disclosure, with deposits returned (§ 55-2515); willful/negligent violation yields actual damages only (§ 55-2517) and never invalidates the transfer. Actual-knowledge standard, expressly "not a substitute for any inspections" (§ 55-2507). Sixteen exemption categories (§ 55-2505: foreclosures, estates, intra-family, new construction, etc.). Alternative forms are permitted (§ 55-2506) — in practice agents use the Idaho REALTORS RE-25 form (idl.idaho.gov copy verified, checked Jul 10, 2026). No inspection is mandated at transfer; NFPA 211 Level 2 at sale stays a NATIONAL STANDARD, not Idaho law.

STATE LAW: the Idaho Consumer Protection Act, Idaho Code § 48-601 et seq., enforced by the AG's Consumer Protection Division. Private action under § 48-608: actual damages or $1,000, whichever is greater, and the court shall award attorney's fees to a prevailing consumer; under § 48-608(2), an elderly (62+) or disabled victim may recover an enhanced penalty of $15,000 or treble actual damages, whichever is greater — but only where the court finds the offender knew or should have known the conduct targeted an elderly/disabled person and the conduct caused a listed serious harm (loss of primary residence, or loss of more than 25% of income, retirement funds or pension payments, or loss of assets essential to health/welfare); attorney's fees to a prevailing plaintiff are in § 48-608(5) (legislature.idaho.gov/statutesrules/idstat/Title48/T48CH6/SECT48-608/, checked Sep 15, 2026). Complaints: ag.idaho.gov/consumer-protection/consumer-complaints/ (also ReportScamsIdaho.com). Right to cancel: the AG's Idaho Rules of Consumer Protection (IDAPA 04.02.01), Subchapter Q — "Cooling-Off Period for Door-to-Door Sales" — gives a 3-business-day right to cancel door-to-door sales of $25 or more, with a mandatory 10-point-type notice and detachable NOTICE OF CANCELLATION form (files.dfm.idaho.gov/dfm-admin-website/rules/current/04/040201.pdf — Rule 170, $25 in the Rule 20.22 definition — checked Sep 25, 2026). The same rulebook regulates Estimates (Subchapter L) and Repairs and Improvements (Subchapter M) — directly applicable to chimney-repair upsells. The hooks interlock: the Contractors Board may discipline a registrant for ICPA violations (§ 54-5215(2)(b)), and hiring an unregistered contractor does not void the homeowner's remedies — it voids the contractor's (no suit for payment, no lien; § 54-5217(2), § 54-5208).

No Idaho AG chimney-sweep alert or chimney-specific enforcement action surfaced (searched Jul 10 and re-checked Sep 25, 2026 against the AG's consumer-protection news archive and consumer-alerts page) — absence noted. The AG maintains the general scam-reporting apparatus (ReportScamsIdaho.com; ag.idaho.gov/consumer-protection/alerts/) and has run recent Treasure Valley home-related fraud warnings (planning-and-zoning fee scheme, 2023). The page's leverage doesn't need a named villain: a door-knocking "chimney inspector" who isn't registered is committing a misdemeanor (§ 54-5217(1)), can be stiffed lawfully (no right to sue, § 54-5217(2); no lien, § 54-5208), owes a 3-business-day cooling-off (IDAPA 04.02.01 Subch. Q), and is exposed to ICPA damages (§ 48-608) — with the § 48-608(2) $15,000/treble elderly enhancement available when a scam against an older homeowner causes one of the serious losses the statute lists.

STATE LAW/LOCAL: the Idaho Building Code Act, Idaho Code § 39-4101 et seq. The Idaho Residential Code is still the 2018 IRC — Parts I, II, III and IX, for one- and two-family dwellings — with state amendments, incorporated by reference in the Building Code Board's rule IDAPA 24.39.30 (current rule text, section notations dated 7-1-24; files.dfm.idaho.gov/dfm-admin-website/rules/current/24/243930.pdf, checked Sep 15, 2026); Idaho Code § 39-4109 names "the version of the International Residential Code adopted by the Idaho building code board" as the Idaho residential code. Part III includes IRC Chapter 10, Chimneys and Fireplaces (no Idaho Chapter 10 amendments found in the rule). The 2025 and 2026 session amendments to § 39-4116 did not change the code edition (history line: "am. 2025, ch. 40, sec. 1, p. 187; am. 2026, ch. 320, sec. 2, p. 1283"): 2025 ch. 40 (H0104, signed Mar 12, 2025, eff. July 1, 2025) defines agricultural buildings for the exemption, and 2026 ch. 320 (H0706, signed Apr 10, 2026, eff. July 1, 2026) added new § 39-4109C (single-stairway building exceptions) and changed the opening of § 39-4116(2) to "Except as otherwise provided in this chapter, local governments…" (legislature.idaho.gov/sessioninfo/2025/legislation/H0104/ and …/2026/legislation/H0706/, bill text …/wp-content/uploads/sessioninfo/2026/legislation/H0706.pdf, checked Sep 25, 2026). The 2024-code update was rejected in 2026: the Division's pending rule Docket 24-3930-2502 would have adopted the 2024 IBC, IRC and IECC (proposed-rule notice Oct 1, 2025); the Senate Commerce & Human Resources Committee approved it (Feb 5, 2026), but the House Business Committee voted to reject it on Feb 17, 2026 ("Rep. Thompson made a motion to reject Docket No. 24-3930-2502 … Motion carried by voice vote") (committee minutes, legislature.idaho.gov/wp-content/uploads/sessioninfo/2026/standingcommittees/260205_schr_0130PM-Minutes.pdf and …/260217_hbus_0130PM-Minutes.pdf, checked Sep 25, 2026); the current compiled IDAPA 24.39.30 still incorporates the 2018 IRC (Sep 25, 2026). The twist is enforcement: under § 39-4116(1), local code enforcement is elective — local governments without a prior program "may elect to implement a building code enforcement program by passing an ordinance" (official text, legislature.idaho.gov/statutesrules/idstat/Title39/T39CH41/SECT39-4116/, checked Sep 25, 2026). Those that do must adopt the state-adopted codes by ordinance (§ 39-4116(2)), may amend only where the amendment establishes "at least an equivalent level of protection" (§ 39-4116(4)), and may not adopt IRC provisions or later versions the board has not adopted (§ 39-4116(4)(b)) — Idaho's opt-out politics run in both directions (§ 39-4116(3) also exempts one- and two-unit dwellings from code sprinkler mandates). Practical map: Boise, Meridian, Nampa, Coeur d'Alene, Idaho Falls and essentially all metro jurisdictions enforce — relines, rebuilds, and solid-fuel appliance installs are permit work there; in non-enforcing rural areas no local building permit exists for structural chimney work at all. But the trades run statewide: where no local program exists, DOPL issues electrical/plumbing/HVAC permits directly, and DOPL's HVAC rules list a "free-standing solid-fuel stove, factory-built gas fireplace, or similar fixture or appliance, including ducts, vents, and flues attached thereto" in the HVAC permit fee schedule (IDAPA 24.39.70.500, current rule, notation 3-28-23; files.dfm.idaho.gov/dfm-admin-website/rules/current/24/243970.pdf, checked Sep 15, 2026) — while built-in solid-fuel appliances (fireplaces/inserts) go through the local building department where one exists (county practice, e.g., Canyon County — LOCAL) NOT YET CONFIRMED confirm the built-in vs. freestanding split on current DOPL guidance before publish. NFPA 211 is not referenced in Idaho statute — NATIONAL STANDARD only.

Two Idaho stories, both real. (a) Airsheds/inversions — where Idaho is genuinely strict: DEQ publishes daily air-quality levels with an action legend under which PM2.5 "Mandatory Restrictions" (RED) prohibit or severely limit burning and solid-fuel devices, with local rules varying (www2.deq.idaho.gov/air/AQIPublic/OutdoorBurn, checked Sep 25, 2026); during an Air Quality Advisory "all outdoor burning is prohibited" (deq.idaho.gov/air-quality/smoke-and-burning/air-quality-advisories/, checked Sep 25, 2026). Two wood-smoke nonattainment sagas anchor the section: the West Silver Valley (Pinehurst/Kellogg, Shoshone County) was designated PM2.5 nonattainment in 2015 driven largely by residential wood heating in winter inversions, attained the standard via a woodstove-changeout program and burn curtailment, and was redesignated attainment with a maintenance plan in 2021 (EPA newsroom + epa.gov/sips-id West Silver Valley maintenance plan, checked Jul 10, 2026); Franklin County (Idaho's share of the Logan UT-ID Cache Valley airshed) was PM2.5 nonattainment 2009–2021 with local wood-burning ordinances in towns like Clifton (DEQ Cache Valley SIP; EPA redesignation Dec 2021, checked Jul 10, 2026). DEQ's Coeur d'Alene office issues winter woodstove-curtailment advisories for Bonners Ferry, Sandpoint, St. Maries, Pinehurst, and Kootenai County; Treasure Valley (Boise) inversions bring their own advisories. DEQ runs woodstove changeout rebates as funding allows (currently St. Maries; deq.idaho.gov/funding/woodstove-funding-resources/, checked Jul 10, 2026) plus a state income-tax deduction for replacing a non-EPA-certified wood stove (surrendered to DEQ for destruction) with an EPA-certified wood stove, pellet stove, or natural-gas/propane unit: 40% of the cost in year one and 20% a year for the next three years, capped at $5,000 per year (Idaho Code § 63-3022C, legislature.idaho.gov/statutesrules/idstat/title63/t63ch30/sect63-3022c/, checked Sep 25, 2026; DEQ restates the same terms). (b) WUI/spark arrestors — real but LOCAL, not statewide: Idaho has no statewide WUI code. LOCAL: the City of Boise amended the International Fire Code to add Chapter 41, Wildland-Urban Interface (WUI) Code (Boise City Code 5-12-53); its § 4117.1 provides "Chimneys serving fireplaces, barbecues, incinerators or decorative heating appliances in which solid or liquid fuel is used, shall be provided with a spark arrester" — 12-gauge woven or welded wire, openings ≤ 1/2", net free area ≥ 4× the chimney outlet (§ 4117.2) (Ord. 48-20, eff. 1-1-2021; amended Ord. 7-25, 2-25-2025; codelibrary.amlegal.com/codes/boise_id/latest/boise/0-0-0-78729, checked Sep 25, 2026); other communities have adopted all or part of the IWUIC (EPA/ICC references; Idaho Firewise guidance is advisory). Rental units: no state solid-fuel rental rule found — NOT CONFIRMED beyond code baseline.

Absence is the finding: Idaho has no standalone CO-alarm statute — no all-rental mandate, no at-sale requirement. STATE LAW (code layer only): CO alarms are required via the Idaho Residential Code (2018 IRC R315, as amended in IDAPA 24.39.30, which modifies R315.2.2 (alterations/repairs/additions) by deleting its Exception 2) in new construction and permit-triggering work where the dwelling has a fuel-burning appliance or attached garage, outside each sleeping area (Idaho Residential Code, up.codes/viewer/idaho/irc-2018; corroborated by the Idaho Dept. of Insurance CO-alarm PSA, doi.idaho.gov/psa/co-alarms/, checked Jul 10, 2026). Existing homes are grandfathered; in non-enforcing rural jurisdictions even the code layer has no enforcer. A permitted chimney or stove job is the natural moment to add alarms — say so on the page.