Idaho building permits

Where to get a building permit in Idaho

Apply to the building department of the city, town or county where the property is (the steps).

Idaho state agencies

These offices set statewide codes or license the trades. They do not issue permits for most home projects.

Building code in Idaho

For homes, the residential code is the 2018 International Residential Code (parts I, II, III and IX), with Idaho amendments collectively named the Idaho Residential Code (2020 Edition)⁹, in effect since July 1, 2024⁶ (statewide minimum; local governments may go further¹⁵).

Every code family, edition and effective date is on Idaho building codes.

State rules on which work needs a permit

Idaho Code §§ 39-4116(5), 39-4103(4); IDAPA 24.39.30.600.03 (R105.2 amendments)

• (5) Local governments shall exempt agricultural buildings from the requirements of the codes enumerated in this chapter and the rules promulgated by the board.¹⁵
• County permits for agricultural buildings allowed for road setbacks and utility easements, at actual cost. A county may issue permits for agricultural buildings to assure compliance with road setbacks and utility easements, provided that the cost for such permits shall not exceed the actual cost to the county of issuing the permits.¹⁵
• Sheds used as part of an agricultural operation. Sheds used as part of an agricultural operation…¹⁵
• Excludes human habitation. (i) A place of human habitation, which means a space in a building for living, sleeping, or cooking.¹⁵
• Counties may not narrow the exemption. (c) Counties shall not alter, amend, deny, limit, or narrow the exemption provided pursuant to this subsection by, including but not limited to, requiring size limitations of agricultural buildings, requiring maximum travel distances to exits within agricultural buildings, or requiring installation of automatic sprinkler systems in agricultural buildings.¹⁵
• 4 feet. Section R105.2. Amend Item number 7 under the “Building” subheading Replace the words “24 inches (610 mm)” with “four (4) feet (1219) mm)” (7-1-24)…⁶
• Prefabricated pools or spas not over 4 ft deep are excepted from the building permit in Post Falls; trade permits still apply. Exception: Prefabricated swimming pools or spas that are not greater than four (4) feet deep.¹⁶
• Flag poles. Section R105.2. Add the following exemption under the “Building” subheading: 11. Flag poles. (7-1-24)…⁶
• Equipment used primarily for industrial chemical process, mineral extraction and mineral processing purposes. (a) Equipment used primarily for industrial chemical process purposes and for mineral extraction and mineral processing purposes.¹⁷
• Modular buildings built in Idaho for installation outside the state. (b) Modular buildings as defined in section 39-4301, Idaho Code, that are constructed in the state of Idaho for installation on building sites outside the state; provided however, that no modular building shall be installed on a building site in the state of Idaho until it has been approved and bears the insignia of approval of the division as being in compliance with the requirements set forth in chapter 43, title 39, Idaho Code.¹⁷

Can local rules be stricter?

Yes¹⁵

Homeowners doing their own work

Idaho Code §§ 54-5205(2)(l), 54-5205(2)(p), 54-5209(1); IDAPA 24.39.20.500; IDAPA 24.39.70.500

• Owners exempt from registration. Owners: Owners who do their own work on their own land and do not intend to sell the property within 12 months are exempt from registration.⁸
• An owner performing construction on the owner’s personal residential real property, whether or not occupied by the owner, provided however, this exemption shall not apply to an owner who is otherwise regulated by this chapter who constructs a building, residence or other improvement on the owner’s property with the intention and for the purpose of promptly selling the improved property, unless the owner has continuously occupied the property as the owner’s primary residence for not less than twelve (12) months prior to the sale of such property…¹⁸
• Person working on own residence owned by another. A person working on the person’s own residence, if the residence is owned by a person other than the resident…¹⁸
• Permit to an exempt person is marked 'no contractor registration provided'. Such registration number presented shall be conspicuously entered on the face of a permit so issued; provided however, a permit may be issued to a person otherwise exempt from the provisions of this chapter provided such permit shall conspicuously contain the phrase "no contractor registration provided" on the face of such permit.¹⁹
• A: Homeowners may purchase a permit only when they themselves are doing electrical work on their primary or secondary residence and/or related outbuildings.¹
• Homeowners making plumbing installations on their own premises under the provisions of Section 54-2602(1)(a), Idaho Code, must secure a plumbing permit by making application to the Division as provided by Section 54-2620, Idaho Code. (3-28-23)…¹¹
• Homeowners making HVAC installations on their own premises under the provisions of Section 54-5002(1)(a), Idaho Code, must secure a HVAC permit by making application to the Division as provided by Section 54-5016, Idaho Code. (3-28-23)…¹²
• Homeowner permits are not valid for work on commercial buildings.¹

Contractor licensing

Idaho Contractor Registration Act, Idaho Code §§ 54-5201 through 54-5219; IDAPA 24.21.01

• Registration, not licensure. The Act requires registration, not licensure.⁸
• $300,000. A certificate issued by an insurance company authorized to do business in the state of Idaho that the applicant has procured and has in effect a general liability policy, including products and continued operations insurance covering the applicant’s construction operations in the sum of not less than $300,000 single limit.⁸
• Separate trade licenses cover electrical, plumbing and HVAC. If you are licensed as an Architect, Electrical Contractor, Engineer or Surveyor, Plumber, Manufactured Home Installer, Service Company Contractor, HVAC installer, etc. you do not have to register, unless you are engaged in contracting beyond the scope of your license.⁸
• Fine of no more than $1,000 or county jail up to six months, or both. Upon conviction, each violation shall be punished by a fine of no more than $1,000 or by imprisonment in the county jail for a term not to exceed six (6) months, or by both, in the discretion of the court.⁸
• No building permit without registration. No Building Permits – You cannot obtain a building permit.⁸
• $2,000. Section 45-525(2), Idaho Code requires a general contractor to provide a disclosure statement, prior to entering into a contract in excess of $2,000 with a homeowner or purchaser of residential real property to construct, alter or repair any improvements on residential real property, or for the purchase and sale of newly constructed property.⁸

Private plan review and inspections

Idaho Code § 39-4116(1) (local contracting only)

• Local governments may contract administration out. Local governments may contract with a public or private entity to administer their building code enforcement program.¹⁵

Selling a home with unpermitted work

Idaho Property Condition Disclosure Act, Idaho Code § 55-2501 et seq.; § 55-2508

• Idaho Code 55-2501 et seq. Idaho Property Condition Disclosure Act (Idaho Code 55-2501, et seq.)²⁰
• 8. Have any substantial additions or alterations been made without a building permit?²¹

Accessory dwelling units (ADUs)

Idaho Code § 67-6541 and § 55-3212, as added and amended by 2026 S1354 as amended (Session Law ch. 265) · in effect July 1, 2026²³

• Cities must allow either one internal ADU or one detached ADU per lot on land zoned single-family. Allow for either one (1) internal accessory dwelling unit within the single-family dwelling or one (1) detached accessory dwelling unit per lot in the rear yard or subject to setbacks required of the primary dwelling…²²
• Cities may not require owner occupancy of the primary dwelling or the ADU. Prohibit an owner-occupancy requirement for the primary dwelling or for the accessory dwelling unit…²²
• Effective February 1, 2027. By February 1, 2027, by resolution or ordinance adopted, amended, or repealed in accordance with the notice and hearing procedures provided under section 67-6509, Idaho Code, each city governing board shall amend its comprehensive plan and land use regulations for all land zoned for single-family residential uses, except for lands falling within an area defined as a historic district under section 67-4607, Idaho Code, or designated as a historic property pursuant to section 67-4614, Idaho Code, to…²²
• No required off-street or guest parking, with stated exceptions. Prohibit requiring any off-street parking or guest parking for any accessory dwelling unit unless the principal dwelling unit does not have off-street parking or the street is not paved and designed or constructed for on-street parking or unless the principal dwelling unit is within one-fourth (1/4) mile of transit, an employment area, or commercial services…²²
• 1,000 square feet. Prohibit limiting the size of an accessory dwelling unit to less than one thousand (1000) square feet or seventy-five percent (75%) of the size of the primary dwelling…²²
• Cities may not ban ADUs in residential zoning areas. No city shall enact or enforce any ordinance, rule, regulation, or policy that bans accessory dwelling units in any residential zoning area within its jurisdiction.²²
• Projects meeting land use requirements are approved administratively. (3) Accessory dwelling unit projects that meet the jurisdiction's established land use requirements shall be approved administratively and as a matter of right, without the need for discretionary approval.²²
• Building codes, fire safety standards and flood plain regulations are not superseded. Building codes, fire safety standards, and flood plain regulations…²²

Applies to

Cities with a population greater than 10,000²²