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Accessory Dwelling Unit (ADU) Permit in Arvada, Colorado

Required for construction of a new Type A (detached, lockable/rentable) or Type B (attached or inside the primary dwelling, lockable/rentable) Accessory Dwelling Unit in Arvada. Both types are treated as a separate dwelling unit under the building code, requiring fire separation from the primary dwelling and a separate HVAC system. CONFIRMED via live re-check 2026-07-17: ADU permits are still issued only to City-licensed contractors (Class I-B, II-B, or III-B) — the live ADU page (arvadaco.gov/338) states plainly 'ADU permits are only issued to Licensed Contractors with a type 1B, 2B or 3B license' with no self-permitting provision present anywhere on the page. The City's proposed homeowner/occupant self-permitting change (listed on arvadaco.gov/1461, still headed 'these changes are still under review') has NOT been adopted as of this verification date, despite the broader July 1, 2026 code-cycle implementation having taken effect for the code suite generally.

Verified 2026-07-17 · Source

When you need this permit

  • Two ADU categories: Type A (detached from the principal dwelling, lockable and rentable) and Type B (located inside or attached to the single-family dwelling, occupants do not live as a single household with the principal dwelling, rented, typically with separate locked-off access)
  • CONFIRMED LIVE 2026-07-17: ADU permits are issued ONLY to Licensed Contractors holding a Type 1B, 2B, or 3B license — homeowner self-permitting remains unavailable per the current arvadaco.gov/338 ADU page, despite being proposed as part of the 2026 code cycle; the proposal is still listed as 'under review' on arvadaco.gov/1461 and has not been confirmed adopted Contractor
  • Water and sanitary sewer service for the ADU must connect to the primary dwelling's existing service lines — a separate utility service is not permitted
  • Fire separation from the primary dwelling and a separate HVAC system are required for both ADU types
  • HOA approval (if applicable) is required in addition to City permits and approvals — a City-issued permit does not override an HOA's own approval requirement

Required documents

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Fee schedule

Building Permit Fee — valuation-based (same Table 18-1 as new construction)An ADU is billed as new residential construction: the City's ADU page does not publish a separate ADU-specific fee line because ADUs are assessed on the same published, cited Table 18-1 valuation-based Building Permit Fee schedule as any other residential construction (arvadaco.gov/1263) — the valuation table itself is the grounded, published fee basis, using the higher of ICC Building Valuation Data (Table 18-2) or actual contract value
Varies by valuation — see Residential Building Permit fee tiers (Table 18-1: $34 minimum up to $5,669.25 + $3.45/$1,000 over $1M)
Use TaxArvada Municipal Code § 98-84; same use-tax split applied to all building permits including ADUs
Assessed on the building valuation using the 58% materials / 42% labor split

Review timeline

Plan reviewArvada’s published plan-review target
5–15 business days

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

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

Inspection process

  1. 1

    Footing / Foundation

    Before concrete pour

  2. 2

    Rough Frame

    Structural framing, fire separation assembly, egress windows

  3. 3

    MEP Rough-In

    Mechanical, electrical, plumbing rough-ins before walls closed; separate HVAC system required from the primary dwelling

  4. 4

    Final

    All work complete; Certificate of Occupancy required before occupancy (issuance can take up to 5 business days)

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

Tips

  • CONFIRMED LIVE 2026-07-17: only a City-licensed contractor (Class I-B, II-B, or III-B) can pull an ADU permit in Arvada — homeowners cannot self-permit an ADU. The City's own 2026 code adoption summary lists 'Allowing ADU's to be built by a homeowner/occupant' as an anticipated administrative change, but that summary page is still headed 'these changes are still under review,' and the live ADU permit page itself contains no self-permitting provision — confirm current status directly with the Building Safety Division before assuming homeowner self-permitting is available. Contractor
  • Arvada's ADU page publishes an explicit review-timeline table by type: Type A = 3 weeks, Type B = 1 to 2 weeks (confirmed live 2026-07-17) — converted to business days (5 days/week, consistent with this file's convention for other permit types) that's roughly 15 business days for Type A and 5-10 business days for Type B, which is the basis for this permit type's reviewTimelineDays figure.
  • ADU water and sewer service must tie into the primary dwelling's existing lines — budget doesn't need to include a new utility tap, but plan review will confirm proper connection sizing.
  • If your property is in an HOA, get HOA approval before or alongside your City permit application — a City permit does not override HOA rules.

Frequently asked questions

Arvada requires an accessory dwelling unit (adu) permit for: Two ADU categories: Type A (detached from the principal dwelling, lockable and rentable) and Type B (located inside or attached to the single-family dwelling, occupants do not live as a single household with the principal dwelling, rented, typically with separate locked-off access); CONFIRMED LIVE 2026-07-17: ADU permits are issued ONLY to Licensed Contractors holding a Type 1B, 2B, or 3B license — homeowner self-permitting remains unavailable per the current arvadaco.gov/338 ADU page, despite being proposed as part of the 2026 code cycle; the proposal is still listed as 'under review' on arvadaco.gov/1461 and has not been confirmed adopted; Water and sanitary sewer service for the ADU must connect to the primary dwelling's existing service lines — a separate utility service is not permitted; Fire separation from the primary dwelling and a separate HVAC system are required for both ADU types; HOA approval (if applicable) is required in addition to City permits and approvals — a City-issued permit does not override an HOA's own approval requirement. If your project isn't listed, confirm with City of Arvada — Building Safety Division at 720-898-7620 before starting work.

In Arvada, the published Building Permit Fee — valuation-based (same Table 18-1 as new construction) is: Varies by valuation — see Residential Building Permit fee tiers (Table 18-1: $34 minimum up to $5,669.25 + $3.45/$1,000 over $1M). Additional published fees: Use Tax — Assessed on the building valuation using the 58% materials / 42% labor split. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Arvada's published plan-review target for an accessory dwelling unit (adu) permit is 5–15 business days.

You'll need: Building Permit Application (eTRAKiT); Plan Set. See the required-documents checklist on this page for details on each.

Arvada requires 4 inspection(s) for an accessory dwelling unit (adu) permit, in order: Footing / Foundation, Rough Frame, MEP Rough-In, Final. Schedule each through City of Arvada — Building Safety Division (720-898-7620).

Apply through City of Arvada — Building Safety Division at 8101 Ralston Road, Arvada, CO 80002. Phone: 720-898-7620, email: buildingpermits@arvada.org. Office hours: Mon–Fri, 8 a.m.–5 p.m.; permits are applied for and paid online via eTRAKiT at arvadapermits.org — permits are no longer processed over the counter. Official information: https://www.arvadaco.gov/332/Building-Permits.

As of a live re-check on 2026-07-17, no — ADU permits in Arvada are issued only to City-licensed contractors holding a Type 1B, 2B, or 3B license. The City has proposed allowing homeowner/occupant self-permitting for ADUs as part of its 2026 code adoption, but this change remains listed as 'still under review' and does not appear on the live ADU permit page — confirm current status with the Building Safety Division before applying.

Arvada recognizes two ADU types: Type A, a detached unit that is lockable and rentable, and Type B, a unit located inside or attached to the primary single-family dwelling with separate, locked-off access, also lockable and rentable. Both must have fire separation and a separate HVAC system from the primary dwelling, and must share the primary dwelling's water/sewer service lines.

Sources & verification

Verified against official sources. Last reviewed 2026-07-17.

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

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