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Building Permit (New Construction, Addition, Alteration, Repair) in Darby, Montana

Required 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

When you need this permit

  • 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

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Fee schedule

Building Permit Fee — valuation $1.00 to $500.00Town of Darby Building Permit Fee Schedule (Res. 649, updated 4/13/2021)
$29.38
Building Permit Fee — valuation $501.00 to $2,000.00Town of Darby Building Permit Fee Schedule
$29.38 for the first $500.00, plus $3.81 for each additional $100.00 or fraction thereof
Building Permit Fee — valuation $2,001.00 to $25,000.00Town of Darby Building Permit Fee Schedule
$86.56 for the first $2,000.00, plus $17.50 for each additional $1,000.00 or fraction thereof
Building Permit Fee — valuation $25,001.00 to $50,000.00Town of Darby Building Permit Fee Schedule
$489.06 for the first $25,000.00, plus $12.63 for each additional $1,000.00 or fraction thereof
Building Permit Fee — valuation $50,001.00 to $100,000.00Town of Darby Building Permit Fee Schedule
$804.69 for the first $50,000.00, plus $8.75 for each additional $1,000.00 or fraction thereof
Building Permit Fee — valuation $100,001.00 to $500,000.00Town of Darby Building Permit Fee Schedule
$1,242.19 for the first $100,000.00, plus $7.00 for each additional $1,000.00 or fraction thereof
Building Permit Fee — valuation $500,001.00 to $1,000,000.00Town of Darby Building Permit Fee Schedule
$4,042.19 for the first $500,000.00, plus $6.19 for each additional $1,000.00 or fraction thereof
Building Permit Fee — valuation $1,000,001.00 and upTown of Darby Building Permit Fee Schedule
$7,010.94 for the first $1,000,000.00, plus $4.56 for each additional $1,000.00 or fraction thereof
Re-roof up to 3,000 square feet (flat fee)Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$50.00
Re-roof over 3,000 square feet (flat fee)Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$75.00
Fence (no fee if under 6 feet)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
Flat Miscellaneous Permit Fee applies at/over 6 feet (specific dollar amount not legibly resolved from the source PDF's table alignment)
Siding (flat fee)Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$50.00
Demolition (flat fee)Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$50.00
Sign (flat fee)Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$75.00
Change of use (flat fee)Town of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$30.00
Footing or Foundation onlyTown of Darby Building Permit Fee Schedule, Miscellaneous Permit Fees table
$1 per lineal foot, or $5 per pier, or based on valuation
Other Inspections and Fees (after-hours, re-inspection, unlisted inspection, additional plan review)Town of Darby Building Permit Fee Schedule
$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

Review timeline

Plan review
Not published — contact the department

How long did your Building Permit (New Construction, Addition, Alteration, Repair) permit actually take in Darby?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

    Tips

    • Darby is fully DLI-certified (Building, Plumbing, Mechanical, Electrical, Swimming Pool) — all permitting and inspection for these trades is handled directly by the Town, not the state, within town limits.
    • The Town's current contracted building inspector is Construct Montana, LLC, (406) 552-3238, inspector@constructmt.com. The DLI's certified-program contact of record is Tim Netzley, (406) 961-2423 (also listed as (406) 880-5832 on the Town's Building Permit Application form).
    • No dedicated permit types for decks, accessory structures (sheds), swimming pools, spas, or water heaters were found published separately on the Town's site — those scopes of work are handled under the general Building Permit (structural) or the trade-specific Electrical/Plumbing/Mechanical permits as applicable, using the same fee tables.
    • No published review-timeline / turnaround-time figure could be found for Darby's own building permit process after exhausting: the Town's Building Permit Information page (darbymt.net/a/building-related-code/), the Building Permit Application PDF, the Fee Schedule PDF, the Contact Us and Government pages, a Wayback Machine check (no snapshot exists for the Darby building-code page), and a direct web search for Darby-specific turnaround language. The Montana DLI Building Codes Bureau publishes a 3-week average review timeline, but that figure explicitly applies only to state-administered (non-certified) jurisdictions and does not govern Darby, which is fully certified and self-administers its own review process — using it here would misattribute a state figure to a certified local program. This field is left null with reviewTimelineVerified:false rather than guessed.

    Frequently asked questions

    Darby requires a building permit (new construction, addition, alteration, repair) for: 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. If your project isn't listed, confirm with Town of Darby Building Department at (406) 821-3753 before starting work.

    In Darby, the published Building Permit Fee — valuation $1.00 to $500.00 is: $29.38. Additional published fees: 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; 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; 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; 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; 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; 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; 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; Re-roof up to 3,000 square feet (flat fee) — $50.00; Re-roof over 3,000 square feet (flat fee) — $75.00; 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); Siding (flat fee) — $50.00; Demolition (flat fee) — $50.00; Sign (flat fee) — $75.00; Change of use (flat fee) — $30.00; Footing or Foundation only — $1 per lineal foot, or $5 per pier, or based on valuation; 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. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

    Darby does not publish a plan-review timeline for this permit. Contact Town of Darby Building Department at (406) 821-3753 for current turnaround.

    You'll need: Building Permit Application; Plot Plan; Construction Drawings (2 sets). See the required-documents checklist on this page for details on each.

    Apply through Town of Darby Building Department at 101 E Tanner Ave / PO Box 37, Darby, MT 59829. Phone: (406) 821-3753, email: darbymontana@usa.net. Office hours: Town Hall: Monday-Friday, 8:00 am - 5:00 pm. Source: Town of Darby Contact Us page (darbymt.net/a/contact-us/). Building permit applications and fee payment are handled in person at Town Hall; the current contracted building inspector is Construct Montana, LLC, (406) 552-3238, inspector@constructmt.com; the Montana DLI-certified program contact of record is Tim Netzley, (406) 961-2423 (also listed as (406) 880-5832 on the Town's own Building Permit Application form).. Official information: https://www.darbymt.net/a/building-related-code/.

    Darby, Montana has 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.pdf; The 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.pdf; Montana 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.pdf; State-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'.. Local amendments apply — see the Darby overview page for the full list.

    The Town of Darby handles all of its own building permits — no need to contact the State Building Department. Darby is a Montana DLI-certified jurisdiction for Building, Plumbing, Mechanical, Electrical, and Swimming Pool permitting within town limits. Source: Town of Darby Building Permit Information page and Montana DLI Building Codes Bureau Certified City, County and Town Programs roster.

    Sources & verification

    Verified against official sources. Last reviewed 2026-07-03.

    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.

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