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Accessory Dwelling Unit (ADU) Permit in Brighton, Colorado

Required for construction of an Accessory Dwelling Unit (ADU) — a permanently constructed dwelling unit, detached or attached to the primary residence, with independent living/sleeping/eating/cooking/sanitation facilities and its own entrance. Governed by the City's January 2026 ADU Homeowner Guide and Land Use Development Code Articles 4 and 5. Notably, the City Council has waived impact and permit fees for ADUs that do not require increased utility service capacity.

Verified 2026-07-06 · Source

When you need this permit

  • One ADU allowed per lot where the primary residence is a compliant detached house or duplex
  • ADU generally may not exceed the living area of the primary residence or 1,200 sq ft, whichever is less
  • Non-permanent structures, mobile homes, motorhomes, and RVs are NOT allowed as ADUs; HUD-certified manufactured homes and state-certified factory-built homes ARE allowed
  • Must comply with all current applicable building codes (2021 IRC/IBC as adopted)
  • Existing utility services must adequately serve the ADU, or must be upsized at owner's cost and associated fees
  • Setback, height, and other zoning criteria per Land Use Development Code Articles 4 and 5 (confirm specifics with the department for the applicable zone district)
  • Submittal requires: plot plan; engineer-stamped soils report and foundation plan if a new foundation is needed; architectural drawings; stamped structural drawings if the ADU is detached, an addition, or alters the existing structure; IECC energy compliance documents if applicable; and Manual D & J calculations if applicable

Required documents

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Fee schedule

Building/Impact/Permit FeesWaiver applies PROVIDED the ADU does not require an increase in utility service capacity; if utility upsizing is needed, standard construction fees and costs apply to that scope
Waived (approved by Brighton City Council)
Construction Use TaxStill due even when impact/permit fees are waived, per the City's ADU Homeowner Guide
3.75% of 50% of total project valuation
School District Fee / Fire District Emergency Services Impact FeePer the City's January 2026 ADU Homeowner Guide
Still due even when impact/permit fees are waived

Review timeline

Plan review
Not published — contact the department

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

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

Inspection process

  1. 1

    Foundation (if new foundation required)

    Before concrete pour

  2. 2

    Framing

    Structural framing complete before cover

  3. 3

    Rough Electrical / Plumbing / Mechanical

    Trade rough-ins before concealment, especially where utility services are being extended or upsized

  4. 4

    Final Inspection

    All work complete per approved plans and applicable codes

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

Tips

  • Brighton City Council has waived impact and permit fees for ADUs, but ONLY if the project does not require an increase in utility service capacity — use tax and school/fire district fees remain due regardless. Confirm your utility connection sizing early, since triggering an upsize brings back standard fees for that portion of the work.
  • If converting an existing residence into an ADU while building a new principal residence on the same lot, a SEPARATE permit application is required for the new principal residence in addition to the ADU conversion application.
  • An ADU generally cannot exceed 1,200 sq ft or the primary residence's living area, whichever is less — call or email Community Development (303-655-2072) to confirm sizing, setbacks, and zone-district-specific criteria before design.

Frequently asked questions

Brighton requires an accessory dwelling unit (adu) permit for: One ADU allowed per lot where the primary residence is a compliant detached house or duplex; ADU generally may not exceed the living area of the primary residence or 1,200 sq ft, whichever is less; Non-permanent structures, mobile homes, motorhomes, and RVs are NOT allowed as ADUs; HUD-certified manufactured homes and state-certified factory-built homes ARE allowed; Must comply with all current applicable building codes (2021 IRC/IBC as adopted); Existing utility services must adequately serve the ADU, or must be upsized at owner's cost and associated fees; Setback, height, and other zoning criteria per Land Use Development Code Articles 4 and 5 (confirm specifics with the department for the applicable zone district); Submittal requires: plot plan; engineer-stamped soils report and foundation plan if a new foundation is needed; architectural drawings; stamped structural drawings if the ADU is detached, an addition, or alters the existing structure; IECC energy compliance documents if applicable; and Manual D & J calculations if applicable. If your project isn't listed, confirm with City of Brighton Community Development Department, Permitting Division at 303-655-2017 before starting work.

In Brighton, the published Building/Impact/Permit Fees is: Waived (approved by Brighton City Council). Additional published fees: Construction Use Tax — 3.75% of 50% of total project valuation; School District Fee / Fire District Emergency Services Impact Fee — Still due even when impact/permit fees are waived. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Brighton does not publish a plan-review timeline for this permit. Contact City of Brighton Community Development Department, Permitting Division at 303-655-2017 for current turnaround.

You'll need: Building Permit Application — ADU building type; Plot Plan; Architectural Drawings. Depending on your project, Brighton may also ask for: Engineer-Stamped Soils Report and Foundation Plan; Stamped Structural Drawings. See the required-documents checklist on this page for details on each.

Brighton requires 4 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation (if new foundation required), Framing, Rough Electrical / Plumbing / Mechanical, Final Inspection. Schedule each through City of Brighton Community Development Department, Permitting Division (303-655-2017).

Apply through City of Brighton Community Development Department, Permitting Division at 500 S 4th Avenue, Brighton, CO 80601. Phone: 303-655-2017, email: 1stop@brightonco.gov. Office hours: City of Brighton main line 303-655-2000; Building Permit Counter direct line 303-655-2017; Homeowner Inspection Line 303-655-2151; Community Development general line 303-655-2072. City Hall closes at noon on Fridays, and all Community Development functions (planning and zoning, permitting and inspections) end at noon on Fridays as well.. Official information: https://www.brightonco.gov/222/Permitting.

Brighton City Council approved waiving impact and permit fees for ADUs, provided the project does not require an increase in utility service capacity. Use tax and school/fire district fees are still due even when the waiver applies.

Only where the primary residence is a compliant detached house or duplex, one ADU per lot. Non-permanent structures, mobile homes, motorhomes, and RVs are not allowed as ADUs, though HUD-certified manufactured homes and state-certified factory-built homes are allowed.

Sources & verification

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

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Accessory Dwelling Unit (ADU) Permit in other cities

Ault, ColoradoBennett, ColoradoBerthoud, ColoradoBurlington, ColoradoCenter, ColoradoCripple Creek, ColoradoDacono, ColoradoFort Lupton, Colorado

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