This is PermitBase’s published record for Darby as of 2026-07-03. It has since been superseded — see the current record. A historical record reflects what PermitBase had verified at that time; it may not capture a real-world change the jurisdiction had made but PermitBase had not yet verified, and it includes any errors we later corrected. Snapshots are never edited retroactively.
Darby building permits
VerifiedDarby, Montana — as published 2026-07-03.
Verified 2026-07-03 · Source
Codes adopted
Montana has a mandatory statewide building code administered by the Montana Department of Labor & Industry (DLI) Building Codes Bureau, amended by the Administrative Rules of Montana (ARM) Title 24, Chapter 301. Cities, counties, and towns may become 'certified' to locally administer permitting and inspection for all or part of the code; a certified local program's adopted code 'may include only codes adopted by the Building Codes Bureau' (ARM 24.301.202). Non-certified areas fall under direct state administration by the DLI Building Codes Bureau. Source: Montana DLI Building Codes Bureau, Certified City, County and Town Programs page (bsd.dli.mt.gov/building-codes-permits/certified-government).Darby is a Montana DLI-certified jurisdiction for Building (B), Plumbing (P), Mechanical (M), Electrical (E), and Swimming Pool (SP) — full trade certification — within Darby town limits ('City Limits' jurisdiction scope). Certified program contact on file with DLI: Tim Netzley, (406) 961-2423. Verified directly against the DLI's official 'Certified City, County and Town Programs' roster PDF (updated 2026-04-22): row reads 'Darby | B, P, M, E, SP | Tim Netzley | 961-2423 | City Limits'. Source: https://bsd.dli.mt.gov/_docs/building-codes-permits/certified-city.pdfThe Town's own Building Permit Application states: 'All work shall conform to the most current building codes - IBC, IRC, IEBC, ISPSC, IECC, NEC, IMC, IFGC, UPC and Montana A.R.M; and applicable local codes' and 'Electrical, Plumbing, Mechanical permits are applied for and inspected by Town of Darby, effective September 16, 2021.' Source: Town of Darby Building Permit Application (amended 2022-03-23), https://www.darbymt.net/a/wp-content/uploads/2022/03/Building-Permit-Application-amended-2022-03-23.pdfMontana uses the Uniform Plumbing Code (UPC), not the International Plumbing Code — confirmed on Darby's own Plumbing Permit Application, which requires a licensed Master Plumber 'in accordance with Title 50, Chapter 60, Section 505, MCA and Sections 8.70.302, 8.70.303, 8.70.304, and 8.70.305 ARM' and states 'All provisions of the Uniform Plumbing Codes and the International Building codes will be strictly enforced.' Source: Town of Darby Plumbing Permit Application (2023-08-22), https://www.darbymt.net/a/wp-content/uploads/2023/08/Plumbing-Permit-Final-TOD-2023-08-22.pdfState-adopted code editions in effect statewide since June 11, 2022 (per DLI Building Codes Bureau, applicable as the baseline Darby enforces as a certified jurisdiction): 2021 IBC, 2021 IRC, 2021 IEBC, 2021 IMC, 2021 IFGC, 2021 IECC, 2021 UPC, 2020 NEC, 2021 ISPSC. Source: Montana DLI Building Codes Bureau, Current Codes page, https://bsd.dli.mt.gov/building-codes-permits/current-codes. Darby's own permit application does not list specific code-edition years locally; no local re-adoption ordinance/administrative order text was found published online (Town Hall does not publish a codified municipal code online) beyond the applications' own reference to 'most current building codes'.
Permit types & fees
Building Permit (New Construction, Addition, Alteration, Repair)
VerifiedRequired for new construction, additions, alterations, repairs, mobile home placement, re-roofing, demolition, and other structural work in the Town of Darby. Reviewed against the IBC, IRC, IEBC, ISPSC, IECC, NEC, IMC, IFGC, and UPC as adopted statewide and enforced locally by Darby as a Montana DLI-certified jurisdiction (certified for Building, Plumbing, Mechanical, Electrical, and Swimming Pool). Applications are submitted in person at Town Hall.
Verified 2026-07-03 · Source
Requirements
- Building permit required for new construction, additions, alterations, repairs, mobile home installation, re-roofing, demolition, siding, signs, fences at/over 6 feet, and changes of use
- Complete and sign the Building Permit Application; fees are based on the Town's valuation-based fee table or the flat Miscellaneous Permit Fee schedule (whichever applies to the scope of work)
- Provide a plot plan showing building location and distances from each side of the lot, indicating alleys or streets
- Provide 2 sets of plans drawn to scale, including foundation, floor and roof framing, floor plans, and exterior elevations (one set may be submitted digitally)
- All work must conform to the most current adopted building codes (IBC, IRC, IEBC, ISPSC, IECC, NEC, IMC, IFGC, UPC) and Montana Administrative Rules (A.R.M.), plus applicable local codes
- Design criteria compliance: 46.0 psf ground snow load, 112 mph wind speed, Seismic Design Category C, severe weathering, 36-inch frost line depth, required ice shield underlayment
- Setback compliance: occupied buildings 25 ft front/rear, 5 ft sides (15 ft corner lot); accessory buildings 25 ft front, 7.5 ft rear, same side setbacks as occupied buildings
Required documents
- RequiredBuilding Permit ApplicationTown of Darby Building Permit Application (amended 2022-03-23), completed and submitted in person at Town Hall (101 E Tanner Ave / PO Box 37, Darby, MT 59829)
- RequiredPlot PlanSite plan showing building location and distances from each lot line, alleys, and streets
- RequiredConstruction Drawings (2 sets)Foundation, floor and roof framing, floor plans, and exterior elevations drawn to scale; one set may be digital
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building Permit Fee — valuation $1.00 to $500.00 | $29.38 | Town of Darby Building Permit Fee Schedule (Res. 649, updated 4/13/2021) |
| Building Permit Fee — valuation $501.00 to $2,000.00 | $29.38 for the first $500.00, plus $3.81 for each additional $100.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Building Permit Fee — valuation $2,001.00 to $25,000.00 | $86.56 for the first $2,000.00, plus $17.50 for each additional $1,000.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Building Permit Fee — valuation $25,001.00 to $50,000.00 | $489.06 for the first $25,000.00, plus $12.63 for each additional $1,000.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Building Permit Fee — valuation $50,001.00 to $100,000.00 | $804.69 for the first $50,000.00, plus $8.75 for each additional $1,000.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Building Permit Fee — valuation $100,001.00 to $500,000.00 | $1,242.19 for the first $100,000.00, plus $7.00 for each additional $1,000.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Building Permit Fee — valuation $500,001.00 to $1,000,000.00 | $4,042.19 for the first $500,000.00, plus $6.19 for each additional $1,000.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Building Permit Fee — valuation $1,000,001.00 and up | $7,010.94 for the first $1,000,000.00, plus $4.56 for each additional $1,000.00 or fraction thereof | Town of Darby Building Permit Fee Schedule |
| Re-roof up to 3,000 square feet (flat fee) | $50.00 | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Re-roof over 3,000 square feet (flat fee) | $75.00 | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Fence (no fee if under 6 feet) | Flat Miscellaneous Permit Fee applies at/over 6 feet (specific dollar amount not legibly resolved from the source PDF's table alignment) | Town of Darby Building Permit Fee Schedule; confidence: this line's exact dollar figure could not be cleanly parsed from the source PDF table layout and is reported as unresolved rather than guessed |
| Siding (flat fee) | $50.00 | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Demolition (flat fee) | $50.00 | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Sign (flat fee) | $75.00 | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Change of use (flat fee) | $30.00 | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Footing or Foundation only | $1 per lineal foot, or $5 per pier, or based on valuation | Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table |
| Other Inspections and Fees (after-hours, re-inspection, unlisted inspection, additional plan review) | $47.00 per hour minimum (half-hour minimum for re-inspection/plan-review line items), or the total hourly cost to the jurisdiction, whichever is greater | Town of Darby Building Permit Fee Schedule |
Electrical Permit
VerifiedRequired for new construction, renovation, or repair of electrical systems within the Town of Darby. Darby is a Montana DLI-certified jurisdiction for electrical permitting and has applied for and inspected electrical permits directly (rather than routing to the state) effective September 16, 2021.
Verified 2026-07-03 · Source
Requirements
- Electrical permit required for new construction, renovation, or repair of electrical systems
- Complete all sections of the Electrical Permit Application; form may be submitted electronically via the form's submit button or in person at Town Hall
- For commercial projects: include load calculations, equipment specifications, grounding detail, and panel/feeder schedule(s)
- Contractor license number and master/journeyman license number required on the application
- Related permit numbers (Building, Plumbing, Mechanical) must be cross-referenced on the application if applicable
Required documents
- RequiredElectrical Permit ApplicationTown of Darby Electrical Permit Application (2021), submitted in person at Town Hall or electronically
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Electrical Permit Fee — valuation $1.00 to $1,000 | $45 for the first $500 plus 6.0% of the balance of construction value | Town of Darby Electrical Permit Application fee table |
| Electrical Permit Fee — valuation $1,001 to $10,000 | $75 for the first $1,000 plus 2.0% of the balance of construction value | Town of Darby Electrical Permit Application fee table |
| Electrical Permit Fee — valuation $10,001 to $50,000 | $255 for the first $10,000 plus 0.5% of the balance of construction value | Town of Darby Electrical Permit Application fee table |
| Electrical Permit Fee — valuation $50,001 or more | $455 for the first $50,000 plus 0.3% of the balance of construction value | Town of Darby Electrical Permit Application fee table |
Plumbing Permit
VerifiedRequired for new construction, remodel/alteration, or addition involving plumbing systems within the Town of Darby, governed by the Uniform Plumbing Code (UPC) and Montana statute (Title 50, Chapter 60, Section 505, MCA; ARM 8.70.302-8.70.305). Darby is a Montana DLI-certified jurisdiction for plumbing permitting and applies for/inspects plumbing permits directly, effective September 16, 2021.
Verified 2026-07-03 · Source
Requirements
- Plumbing work must be performed by a licensed Master Plumber, per Title 50, Chapter 60, Section 505, MCA and ARM 8.70.302-8.70.305
- Permit becomes null and void if authorized work has not commenced within 180 days, or if it exceeds the expiration date on the issued permit
- 24 hours' notice required for all inspections
- Applicant/property owner is responsible for compliance with all applicable Uniform Plumbing Code and International Building Code provisions
Required documents
- RequiredPlumbing Permit ApplicationTown of Darby Plumbing Permit Application (final, 2023-08-22), submitted at Town Hall (101 E Tanner Ave / PO Box 37, Darby, MT 59829)
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Plumbing Permit Fee — valuation $1.00 to $1,000 | $75 for the first $1,000 plus 2.0% of the balance of construction value | Town of Darby Plumbing Permit Application fee table (the same table also lists a $45-for-first-$500-plus-6.0%-of-balance tier consistent with the Electrical/Mechanical fee structure) |
| Plumbing Permit Fee — valuation $1,001 to $10,000 | $225 for the first $10,000 plus 0.5% of the balance of construction value | Town of Darby Plumbing Permit Application fee table |
| Plumbing Permit Fee — valuation $10,001 to $50,000 | $455 for the first $50,000 plus 0.3% of the balance of construction value | Town of Darby Plumbing Permit Application fee table |
Mechanical / HVAC Permit
VerifiedRequired for new construction, renovation, or repair of mechanical (HVAC) systems within the Town of Darby. Darby is a Montana DLI-certified jurisdiction for mechanical permitting and applies for/inspects mechanical permits directly, effective September 16, 2021.
Verified 2026-07-03 · Source
Requirements
- Mechanical permit required for new construction, renovation, or repair of mechanical systems
- Complete all sections of the Mechanical Permit Application; form may be submitted electronically or in person at Town Hall
- For new commercial projects: include load calculations and equipment specifications
- Contractor license number required on the application
Required documents
- RequiredMechanical Permit ApplicationTown of Darby Mechanical Permit Application (2021), submitted in person at Town Hall or electronically
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Mechanical Permit Fee — valuation $1.00 to $1,000 | $75 for the first $1,000 plus 2.0% of the balance of construction value | Town of Darby Mechanical Permit Application fee table (the same table also lists a $45-for-first-$500-plus-6.0%-of-balance tier) |
| Mechanical Permit Fee — valuation $1,001 to $10,000 | $255 for the first $10,000 plus 0.5% of the balance of construction value | Town of Darby Mechanical Permit Application fee table |
| Mechanical Permit Fee — valuation $10,001 to $50,000 | $455 for the first $50,000 plus 0.3% of the balance of construction value | Town of Darby Mechanical Permit Application fee table |
Sources & verification
Verified against official sources. Last reviewed 2026-07-03.
Fee schedules
Applications & forms
Codes & ordinances
Department & other records
Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Darby building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.