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Permitting Authorities / City of Nampa - Building Safety & Code Division

City of Nampa - Building Safety & Code Division

Adopted code

The building permitting authority for the City of Nampa, Canyon County, Idaho, and the second-largest city in the state. Building Safety & Code sits inside the City's Development Services department at 500 12th Avenue South, and it states that it provides permit processing and inspection services "within the City of Nampa city limits", so its authority stops at the municipal boundary. Nampa issues a dedicated re-roof permit and publishes its own Reroof Permit Application, which states on its face that it "is for all reroof projects" and asks whether the job is a tear off or a cover. Two things a roofer should know before quoting here. Nampa fills in the residential code's climate table itself and answers the ice barrier row NO, so no ice barrier is mandated even though the same table sets weathering as Severe. And the City publishes two different wind speeds -- 115 mph ultimate on the design criteria sheet its building division hands out today, and 90 mph in the version of the table codified in the City Code -- so confirm which figure the plan reviewer is applying before designing to either. Applications and inspection requests run through the City's Citizen Self Service portal.

Jurisdiction
City of Nampa, Idaho
Jurisdiction type
city
Address
500 12th Avenue South, Nampa, ID 83651
Contact
  • url: https://www.cityofnampa.us/1685/Building-Permit-Process
  • phone: 208-468-5435
Permit portal
Permit portal
Roofing permit required
Required
Contractor registration required
Required
Registration details
  • state_level: STATEWIDE, AND INDEPENDENT OF WHATEVER THIS JURISDICTION REQUIRES. Idaho Code 54-5204(1), in the Idaho Contractor Registration Act (Title 54, Chapter 52): "On and after January 1, 2006, it shall be unlawful for any person to engage in the business of, or hold himself out as, a contractor within this state without being registered as required in this chapter." A roofer is inside the definitions rather than at their edge: "Construction" means "the performance of building, altering, repairing, adding to, subtracting from, improving, reconstructing, moving, excavating, wrecking or demolishing any building ... or improvement to real property, or to do any part thereof" (54-5203(2)), and "Contractor" means any person who "undertakes, offers to undertake, purports to have the capacity to undertake, or submits a bid to, or does himself or by or through others, perform construction" (54-5203(3)(a)). Roofing is not separately licensed in Idaho, so this registration is the whole of the state credential. THRESHOLD: 54-5205(2)(f) exempts work on "one (1) undertaking or project considered casual, minor, or inconsequential, whether by one (1) or more contracts, the aggregate contract price of which, for labor and materials and all other items, is less than two thousand dollars ($2,000)" -- a per-project figure covering labour and materials together, not annual revenue, and the same paragraph voids the exemption where the work is part of a larger project or where one job is split into contracts of less than two thousand dollars. A residential reroof is rarely under $2,000. An owner working on his own residential property is exempt (54-5205(2)(l)), as is an owner who hires a registered contractor (54-5205(2)(k)); an employee on wages is exempt but an unregistered subcontractor is not (54-5205(2)(a)). CONSEQUENCES OF NOT REGISTERING, and a homeowner should check: an unregistered contractor "shall be deemed to have conclusively waived any right to place a lien upon real property" (54-5208); may not "bring or maintain any action in any court of this state for the collection of compensation" without proving registration throughout the work (54-5217(2)); and is guilty of a misdemeanor punishable by a fine up to $1,000, up to six months in county jail, or both (54-5217(1)). AT THE PERMIT COUNTER: 54-5209(1) requires every county, municipality or district that issues building permits to request the contractor's Idaho registration number and print it on the face of the permit, or else print "no contractor registration provided"; 54-5209(2) requires the permit to be posted at the site so that statement is visible. WHAT IT TAKES: an application under oath, proof of worker's compensation coverage or a statement why it is not required, and a general liability policy including products and completed operations coverage of not less than $300,000 single limit (54-5210(1)). It is a registration, not a competency licence -- there is no examination. Administered by the Idaho Contractors Board within the Division of Occupational and Professional Licenses (54-5206(1)); registrations can be checked by name at the Division's public search.
  • city_level: NOT REQUIRED BY THE CITY, AND NAMPA REPEALED THE REGISTRATIONS IT USED TO HAVE. This is an earned reading rather than an absence of information. Nampa City Code Title 5, Business Licenses, was read in full -- all thirteen chapters: general licensing provisions; tree service; commercial applicator; concessionaires; peddlers and solicitors; carnivals and amusement rides; massage establishment licensing; vehicle escort service; pawnbrokers; alcoholic beverage control; adult businesses; private security service; and used precious metal jewelry and gem dealers. No chapter licenses or registers construction contractors, and roofing is not mentioned anywhere in the title; the only trade credential in it is the city tree contractor's license at 5-2-11, for work on trees in the public right-of-way. Title 4, Building Regulations, was read in full as well. It once carried contractor registration for two trades, and the City took both out: the editor's notes at sections 4-3-3 and 4-4-3 record that "Ord. No. 4353, adopted Dec. 4, 2017, effective Jan. 1, 2018 repealed section 4-3-3, which pertained to contractor registration" and did the same for the electrical registration at 4-4-3. What Title 4 does still require is a state licence for other trades, not for roofing: plumbing, electrical and mechanical installations must be performed by state licensed contractors under 4-3-5, 4-4-4 and 4-5-3. The state registration above applies in Nampa regardless, and the City asks for the number on the face of its Reroof Permit Application, which requires the applicant either to certify a current Idaho Contractor Registration Number "issued by the State of Idaho as required by Chapter 52, Title 54 of the Idaho State Code" or to declare "I am not providing a contractor registration number because I am exempt per Idaho State Code 54-5205." The City states the practical effect of the owner exemption on its Residential FAQ: "Homeowners may apply for building, mechanical, electrical or plumbing permits on their primary or secondary residence without registering as a contractor with the State of Idaho if you plan on living in the residence within 12 months after completion of the project. The owner must self perform all work under a homeowner's permit." Anyone else doing the work "must be a State of Idaho registered building contractor or a licensed sub-contractor in that trade and must pull permit a permit and perform the work."
Permit process note
Nampa publishes a standalone Reroof Permit Application whose first line reads, "This application is for all reroof projects." One form covers both tracks, with a Residential and a Commercial box to tick. It asks four questions that decide the job: "Is this a roof tear off?", "Total Roof Area", "Is this a roof cover?" and the existing and proposed roofing materials, plus the roof insulation location, type and R-value. The submittal checklist wants a site plan or aerial "Identifying with structures are being reroofed" and, for residential work, the manufacturer installation instructions; commercial jobs additionally need a roof layout showing roof drainage and the location of mechanical equipment, and material data sheets if a TPO roof is going on. Project value must be the real cost, and Nampa City Code 4-2-4 lets the building official compare the value declared at application against the final cost at substantial completion and invoice the difference before releasing the certificate. The application also carries the Idaho contractor-registration declaration described under contractor registration, and it must be signed twice, once by the applicant and once by the contractor or owner. HOW THE PROCESS RUNS. Applications go through the City Citizen Self Service portal or in person, then intake, plan review, issuance, inspections and a certificate; the City states that a full list of required "inspections & conditions can be found on your Permit", so read the permit itself for the inspection stages rather than relying on a published list. Inspection requests are made through the same portal and must be in before midnight the day before; regular inspection hours are Monday to Friday, 8:00 AM to 4:00 PM, and a specific date and time needs a written request to the building official 48 hours ahead. The complete set of approved permit plans must be on site for every inspection, and failing to be ready for a requested inspection can draw a $55.00 re-inspection fee. FEES. Permit fees are set by a schedule adopted by City Council resolution and are based on the valuation of total construction costs, starting at $22.20 for the first $500 of value; payment is due when the permit is issued and no permit issues until fees are paid (Nampa City Code 4-1-4). Up to 80 percent of the permit fee can be refunded on written request within 180 days of issuance, and 100 percent less administrative fees where no work has commenced, but plan review fees are not refunded once the review is done. A permit goes invalid if work does not start within 180 days or is abandoned for 180 days, and reactivating an expired permit costs an hourly administrative fee with a one-hour minimum and puts the project under the codes in effect at the time of reactivation. STARTING WITHOUT THE PERMIT IS EXPENSIVE. Nampa City Code 4-1-5(D) doubles the permit fee for anyone who begins work without every required permit, with a carve-out only for emergency repair work done outside business hours where the permit is obtained on the next business day, and 4-1-13 adds a separate special investigation fee equal to the permit fee whether or not a permit is eventually issued.
Adopted code
LOCALLY ENACTED, ON TOP OF A STATE-MANDATED EDITION. Nampa City Code 4-2-1 ratifies and adopts as "the Building Code of Nampa City" the 2018 International Building Code; the "2018 International Residential Code Parts I through VI, and IX (IRC) with amendments as published by the International Code Council, as adopted by the State of Idaho or the Idaho Building Code Board, together with any amendments or revisions thereto made by the Idaho Building Code Board through the negotiated rulemaking process, including Appendix Q - Tiny Houses and Appendix S - Strawbale Construction"; the 2018 International Existing Building Code; and the 2018 International Energy Conservation Code, each with the Board's amendments. The City also adopts the 2021 International Building Code's mass timber provisions by section and table number, the 2015 NFPA 30 code for motor fuel dispensing facilities and repair garages, and the 2015 NFPA 99 health care facilities code. The adopting ordinances are Ord. 4353, adopted December 4, 2017 and effective January 1, 2018, amended by Ord. 4460 of August 19, 2019, Ord. 4539 of November 16, 2020 and Ord. No. 4624, section 1, of November 1, 2021. The City Code as published is codified through Ordinance No. 4907, adopted January 5, 2026. The City's own Code Resources page lists the same current adopted codes, and adds the 2018 International Mechanical Code, the 2018 International Fuel Gas Code, the 2017 Idaho State Plumbing Code and the 2023 National Electrical Code. Nampa City Code 4-2-1(B) sets the tie-breaker: where the City Code and an adopted code are inconsistent, "the more restrictive requirement or standard shall apply." THE STATE LAYER. Idaho's residential code is set by the Idaho Building Code Board, not by the city. IDAPA 24.39.30.600.03 adopts the "International Residential Code, 2018 Edition ... Parts I, II, III, and IX of the 2018 Edition for one (1)- and two (2)-family dwellings", effective July 1, 2024, and Idaho Code 39-4116(2) requires a local government that issues building permits and performs code enforcement to adopt the Idaho residential code parts I-III and IX by ordinance. Nampa's adoption reaches further, to Parts I through VI; roofing sits in Part III and is inside both. Idaho Code 39-4116(2) also bars a local jurisdiction from adopting provisions of a later IRC edition the Board has not adopted, so a city cannot be ahead of the state, and Nampa is not. Idaho Code 39-4116(6) settles which edition governs a given job: "Permits shall be governed by the laws in effect at the time the permit application is received."
Drip edge
Required — IDAPA 24.39.30.600.03, the State of Idaho's complete list of amendments to the 2018 International Residential Code, read in full, does not touch Chapter 9, Roof Assemblies, and Nampa City Code Title 4, Building Regulations, all thirteen chapters read in full, does not touch it either. The base 2018 IRC drip-edge requirement for asphalt shingle roofs, Section R905.2.8.5, therefore applies unmodified. Confirm the flashing detail and the fastener spacing against the shingle manufacturer's printed instructions as well, which the code makes binding and which Nampa asks for with a residential reroof application. About drip edge
Ice & water shield
Not required — Sourced from Nampa's own climatic and geographic design criteria, not inferred from climate, and the City states it twice. Nampa City Code 4-2-2 amends Table R301.2(1) of the adopted residential code and answers its "ICE BARRIER UNDERLAYMENT REQUIRED" row NO, cross-referencing the base code sections R905.2.7.1, R905.4.3.1, R905.5.3.1, R905.6.3.1, R905.7.3.1 and R905.8.3.1 "where there has been a history of local damage from the effects of ice damming." The Climate and Geographic Design Criteria sheet the City's Building Safety and Code division publishes today, dated 3/12/2024, prints the same answer: "ICE BARRIER UNDERLAYMENT REQUIRED: No". The same two documents set weathering as Severe and print "WINTER DESIGN TEMP: 10 degrees F", so the absence of an ice barrier requirement here is a deliberate entry by the City rather than a mild-climate default. Idaho's state rule does not answer this question: IDAPA 24.39.30.600.03 amends nothing in Chapter 9 of the 2018 International Residential Code, and Table R301.2(1) is the one part of Part III that Idaho Code 39-4116(4)(c) leaves a city or county free to fill in and amend for local conditions. An ice barrier is not forbidden, and a roofer may install one by choice or because a manufacturer's warranty asks for it. Neighbouring jurisdictions complete the same table for themselves and may answer differently, so confirm the answer for the address, not for the metro. About ice & water barrier
Impact-resistant roofing
Not required — No impact-resistance mandate applies in Nampa. IDAPA 24.39.30.600.03, the State of Idaho's complete list of amendments to the 2018 International Residential Code, read in full, contains no amendment to Chapter 9, Roof Assemblies, and no UL 2218, Class 4 or FM 4473 impact-rating reference anywhere in the rule. Nampa City Code Title 4, Building Regulations -- the City's adopting instrument at 4-2-1, its full amendment list at 4-2-2 and all thirteen chapters of the title -- was read in full and contains no such reference either. Neither the state's nor the city's adopted code imposes an impact-resistant roof covering requirement. An insurance discount for impact-rated shingles, where a carrier offers one, is a matter between the homeowner and the insurer and is not a code requirement.
Repair permit threshold
Nampa sets no size, area or dollar threshold below which a roof repair escapes a permit. Nampa City Code 4-2-3 makes it "unlawful for any person, firm or corporation to erect, construct, enlarge, alter, repair, improve, remove, convert, demolish, or install any building, structure, or manufactured/mobile home without first obtaining a building permit", and the City states on its own Building Safety and Code page that "Permits are required before performing any new construction, building addition, alteration, or repair of existing buildings and structures, and for all plumbing, electrical, or mechanical work." Its Residential FAQ answers the question directly, listing among the work that needs a building permit "Re-roofing an existing structure, includes overlays and complete tear off and reroof of residential structures." An overlay needs a permit in Nampa just as a tear-off does. The City rewrites the adopted code list of work exempt from permit at Nampa City Code 4-2-2, and that replacement list was read in full: its twelve items are small detached accessory structures under 200 square feet, oil derricks, short retaining walls, small water tanks, low sidewalks and driveways, finish work such as painting and papering, temporary stage sets, small above-ground prefabricated swimming pools, nursery shade cloth structures, playground equipment, small window awnings, and low movable fixtures and partitions. No roofing item appears on it, and the City publishes no separate roof repair threshold. The State of Idaho adds none either: its only two amendments to the same exempt-work list change a dimension in item 7 and add flag poles. Do not rely on the hundred-square-foot roof repair figure that appears in Idaho state building code rules. It sits inside the definition of "Minor Alteration", which that rule says "is used for the purpose of administering annual permits" -- a blanket permit the state issues to state agencies for work on buildings they already own or operate. It is not a permit exemption for a homeowner or a roofing contractor anywhere in Idaho.
Wind design criteria
Nampa fills in the adopted residential code's Table R301.2(1), Climatic and Geographic Design Criteria, itself, and the City publishes two versions of that table with two different wind figures. Confirm which one your plan reviewer is applying before you design to either. The Climate and Geographic Design Criteria sheet the Building Safety and Code division publishes today, dated 3/12/2024, prints "WIND DESIGN CRITERIA: ULTIMATE AND SPEED: 115 ULT", with "Wind speed from the basic wind speed map [Figure R301.2(5)A]. Wind exposure category shall be determined in accordance with Section R301.2.1.4 Wind Design." The codified table, at Nampa City Code 4-2-2 as last amended by Ord. No. 4624 of November 1, 2021, answers its "WIND DESIGN SPEED" row, in mph, 90, with "Wind speed from the basic wind speed map [Figure R301.2(4)A]." Only the 2024 sheet labels its basis, and it labels it ultimate; the codified table prints no basis label and cites a different figure of the model code. A nominal and an ultimate wind speed are different numbers describing the same loading, so these two figures are not to be averaged, reconciled or converted into one another -- use the figure the City tells you to use, on the basis the City states for it. Everything else in the wind block agrees across both documents -- topographic effects "No In accordance with Section R301.2.1.5", "SPECIAL WIND REGION: No" and "WIND-BORNE DEBRIS ZONE: No". The rest of the table also agrees across both: a ground snow load of 20 psf, with the rider that "Design roof load shall not be less than a uniform snow load of 25 psf."; "SEISMIC DESIGN CATEGORY: B"; weathering Severe; "FROST LINE DEPTH: 24 inches"; termite exposure Slight to Moderate; "WINTER DESIGN TEMP: 10 degrees F"; and an air freezing index of 860. One statewide wind rule that reaches Nampa: the State of Idaho deletes the model code's wind-borne debris opening-protection section, IDAPA 24.39.30.600.03(d) reading "Section R301.2.1.2 Protection of Openings. Delete." That is an opening -- window and door -- provision rather than a roofing one, and under Idaho Code 39-4116(4)(b) a local jurisdiction may not re-adopt a provision the Idaho Building Code Board has expressly rejected.
Roof layer limit / recover
Neither the State of Idaho nor the City of Nampa modifies the model rule. IDAPA 24.39.30.600.03, the Idaho Building Code Board's complete list of state amendments to the 2018 International Residential Code, seventeen items, read in full, contains no amendment to Chapter 9, Roof Assemblies. Nampa City Code Title 4, Building Regulations -- all thirteen chapters, including the City's own amendment list at 4-2-2 -- was read in full and contains no amendment to Chapter 9 either; the only reference to the roofing chapter anywhere in the title is the cross-reference to the base code ice barrier sections inside the City's version of Table R301.2(1). The base 2018 IRC provisions therefore apply unmodified. Base-code rule, 2018 IRC Section R908.3.1.1, Roof recover not allowed: a roof recover is not permitted where the existing roof or covering is water-soaked or has deteriorated to the point that it is not an adequate base for additional roofing; where the existing roof covering is slate, clay, cement or asbestos-cement tile; or where the existing roof already has two or more applications of any type of roof covering. One existing layer may be recovered; a second forces a full tear-off. The City states the same limit on the face of its own Reroof Permit Application, which asks "Is this a roof cover?" and answers it with the note "No more than two layers are allowed at completion". A local Idaho amendment to this rule would be unusually visible: Idaho Code 39-4116(4)(d) allows a city or county to amend this part of the residential code only by ordinance, on a recorded finding that "good cause for building or life safety exists" and that the amendment is "reasonably necessary", after a public hearing noticed in the official newspaper with at least thirty days' written notice to the local chapters of the industry bodies listed in Idaho Code 39-4109(5).
Deck & sheathing requirements
IDAPA 24.39.30.600.03, the State of Idaho's complete list of amendments to the 2018 International Residential Code, read in full, contains no amendment to Chapter 8, Roof-Ceiling Construction, which carries the code's roof sheathing provisions, nor to Chapter 9, Roof Assemblies. Nampa City Code Title 4, Building Regulations, all thirteen chapters read in full, does not amend Chapter 8 or Chapter 9 either; the City's structural amendments at 4-2-2 reach the garage fire separation, ground snow load, footings and the climate table, and stop there. The base 2018 IRC roof sheathing and decking requirements therefore apply unmodified, along with the shingle manufacturer's printed installation instructions, which the code makes binding and which Nampa requires with a residential reroof application. Two City figures a decking decision may turn on, both from the City's own climate table: the ground snow load is 20 psf and "Design roof load shall not be less than a uniform snow load of 25 psf."
Sales & use tax
6.0% -- the Idaho state rate, with no local add-on. Idaho Code 63-3619 imposes the state sales tax "at the rate of six percent (6%)". Idaho has only two kinds of local sales tax, and neither applies here: a resort-city local-option tax, which Idaho Code 50-1044 confines to resort cities "with a population not in excess of ten thousand (10,000)" and which the Idaho State Tax Commission's own list of participating cities does not include Nampa in; and an auditorium-district tax, which the Tax Commission states "can charge a local sales tax only for short-term lodging (30 days or less)" and so never reaches roofing work. Nampa lies within the Nampa Auditorium District, but that district's tax applies only to short-term lodging and does not change the rate on a roof. Idaho counties levy no sales tax at all, so Canyon County adds nothing. HOW A ROOF IS TAXED, which matters more than the rate: the Tax Commission's contractor guidance states that "Idaho sales tax law says contractors are the consumers (end users) of all the goods they use. As a result, they must pay sales tax on all purchases", and it names roofers among the contractors it covers. The roofer pays the 6% on materials at the supply house; the homeowner's invoice carries no sales tax line at all, on materials or on labour, because "a contractor doesn't charge sales tax to the customer" and the tax is absorbed into the bid. The Commission adds that "if sales tax is charged on the bill, the customer can refuse to pay it." A customer's own sales-tax exemption does not carry over to the contractor.

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