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Accessory Dwelling Unit (ADU) Permit in Berthoud, Colorado

Berthoud's zoning code permits accessory dwelling units in at least its R4 (mixed-use residential) zone district, where an ADU counts as 0.33 units toward overall project density and is listed as requiring approval via a Building Permit following the applicable land-use approval (Table 3.3 of the Berthoud Development Code). There is no dedicated standalone 'ADU permit' fee line on the Town's fee schedule — an approved ADU is built and permitted through the standard residential building-permit process once zoning/land-use approval is secured.

Reviewed 2026-07-06 · Source

When you need this permit

  • Zoning/land-use review to confirm the parcel's zone district permits an ADU and to determine which approval track applies (the Town's Table 3.3 land-use table lists ADUs as requiring a Building Permit following the applicable land-use approval in at least the R4 district) — confirm the specific zone district and any use-by-special-review requirement with Planning & Zoning before applying for the building permit itself
  • Once zoning approval is secured, the ADU is permitted as a standard Residential Building Permit (new construction) or Residential Addition permit (if attached/converted from existing space), subject to the same 2024 IRC design criteria, Appendix RM electric/solar-ready provisions, and contractor-licensing requirements as any other residential structure
  • Contractor must hold the applicable Town of Berthoud contractor license (Residential General Contractor C, or Trade Contractor if the ADU qualifies as a small accessory structure) per Ordinance No. 1376 Contractor

Required documents

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Fee schedule

Building Permit Fee (standard new-construction/addition valuation-based fee)No distinct ADU-specific fee line exists on the Town's 2026 fee schedule; an ADU is billed under the same schedule as any comparable new residential structure or addition
Per the 2024 IRC Appendix AB valuation-based fee table, plus $50 Administration + $50 Technology fee

Review timeline

Plan review
Not published — contact the department

How long did your Accessory Dwelling Unit (ADU) Permit permit actually take in Berthoud?

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

Inspection process

  1. 1

    Foundation

    Before concrete pour (if new footings)

  2. 2

    Framing

    Structural framing complete before cover

  3. 3

    Rough Electrical / Plumbing / Mechanical

    Trade rough-ins before concealment

  4. 4

    Final Inspection

    All work complete per approved plans and applicable codes

See the full Berthoud inspection guide — scheduling & re-inspection fees →

Tips

  • Confirm your parcel's zone district with Planning & Zoning before assuming ADUs are allowed — the corpus's available search results confirm ADUs are recognized and counted toward density (0.33 units) in at least the R4 district, but full townwide applicability across all residential zone districts was not independently confirmed in this research pass.
  • Budget for a separate zoning/land-use approval step (and its own fee, e.g. Site Plan review at $5,000 or Use by Special Review at $7,500 per the Town's Application Fees schedule) in addition to the building-permit fee itself — these are Planning Division fees, not Building Department fees.

Frequently asked questions

Berthoud requires an accessory dwelling unit (adu) permit for: Zoning/land-use review to confirm the parcel's zone district permits an ADU and to determine which approval track applies (the Town's Table 3.3 land-use table lists ADUs as requiring a Building Permit following the applicable land-use approval in at least the R4 district) — confirm the specific zone district and any use-by-special-review requirement with Planning & Zoning before applying for the building permit itself; Once zoning approval is secured, the ADU is permitted as a standard Residential Building Permit (new construction) or Residential Addition permit (if attached/converted from existing space), subject to the same 2024 IRC design criteria, Appendix RM electric/solar-ready provisions, and contractor-licensing requirements as any other residential structure; Contractor must hold the applicable Town of Berthoud contractor license (Residential General Contractor C, or Trade Contractor if the ADU qualifies as a small accessory structure) per Ordinance No. 1376. If your project isn't listed, confirm with Town of Berthoud Planning & Building Department at 970-532-2643 (option 3); alt. 970-344-5828 before starting work.

No distinct ADU permit fee line appears on the Town's 2026 Schedule of Rates, Charges and Fees. Once zoning/land-use approval for an ADU is obtained, the structure is permitted through the same valuation-based Building Permit Fee table used for any comparable new residential construction or addition.

Berthoud does not publish a plan-review timeline for this permit. Contact Town of Berthoud Planning & Building Department at 970-532-2643 (option 3); alt. 970-344-5828 for current turnaround.

You'll need: Land-Use/Zoning Approval (Planning Division); Building Permit Application (CommunityCore). See the required-documents checklist on this page for details on each.

Berthoud requires 4 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation, Framing, Rough Electrical / Plumbing / Mechanical, Final Inspection. Schedule each through Town of Berthoud Planning & Building Department (970-532-2643 (option 3); alt. 970-344-5828).

Apply through Town of Berthoud Planning & Building Department at 807 Mountain Ave, Berthoud, CO 80513 (PO Box 1229, Berthoud, CO 80513). Phone: 970-532-2643 (option 3); alt. 970-344-5828, email: building@berthoud.org. Office hours: Main line 970-532-2643 option 3 (fax 970-532-0640). Inspections are performed under contract by SAFEbuilt/ProCode — phone 970-305-3161 ext. 1, online scheduling via the Town's CommunityCore portal; inspection requests must be received by 4 p.m. for next-business-day completion.. Official information: https://www.berthoud.org/169/Building-Department.

Berthoud, Colorado has adopted: 2024 International Building Code (IBC) — Chapters 1-33 and Appendix Chapter I, adopted by reference with local amendments (Berthoud Municipal Code Chapter 11.1); 2024 International Residential Code (IRC) — Chapters 1-43 and Appendix AB, adopted by reference with local amendments (Chapter 11.2). Fee schedule is explicitly keyed to '2024 IRC Appendix AB' as the valuation-based fee table.; 2024 International Existing Building Code (IEBC) — Chapters 1-16 (Chapter 11.3); 2024 International Energy Conservation Code (IECC) — Commercial Chapters 1-6, Residential Chapters 1-6, INCLUDING Appendix CK (Colorado Model Electric and Solar Ready Code — Commercial) and Appendix RM (Colorado Model Electric and Solar Ready Code — Residential) (Chapter 11.4); 2023 National Electrical Code (NEC / NFPA 70) (Chapter 11.5); 2024 International Plumbing Code (IPC) — Chapters 1-13 (Chapter 11.10); 2024 International Mechanical Code (IMC) — Chapters 1-15 (Chapter 11.16); 2024 International Fuel Gas Code (IFGC) — Chapters 1-8 (Chapter 11.17); Colorado State Regulation 86 (Graywater Systems) — Town of Berthoud is the designated local agency for graywater oversight (Chapter 11.18); 2024 International Swimming Pool and Spa Code (ISPSC) — Chapters 1-11 (Chapter 11.19); 2024 International Property Maintenance Code (IPMC) — Chapters 1-8 (Chapter 11.20); HB22-1362 statewide energy code floor: Berthoud's 2024 IECC adoption explicitly incorporates Appendix CK and Appendix RM (the Colorado Energy Office's model Electric Ready / Solar Ready / EV Ready code), satisfying HB22-1362's statewide low-energy/electric-and-solar-ready requirement. Confirmed directly from the Town's own 2024 I-Code Amendment ordinance text (Berthoud Municipal Code Chapter 11.4), not inferred.. Local amendments apply — see the Berthoud overview page for the full list.

Sources & verification

Key facts verified against official sources. Last reviewed 2026-07-06.

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 Berthoud building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.