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. As of the lastVerified date, ADU permits are issued only to City-licensed contractors (Class I-B, II-B, or III-B) — the City's proposed 2026 code cycle would allow homeowner/occupant self-permitting, but this was not yet confirmed as adopted.
Verified 2026-07-01 · 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)
- As of lastVerified date, ADU permits are issued ONLY to Licensed Contractors holding a Type 1B, 2B, or 3B license — homeowner self-permitting was not yet confirmed available (proposed for the 2026 code cycle; verify current status before applying)
- 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
- Req
Building Permit Application (eTRAKiT)
Login to Arvada Permits, enter required information, and upload PDF plans and related documents
- Req
Plan Set
Full construction drawings showing fire separation, HVAC system, and connection to the primary dwelling's utility services
Fee schedule
| Fee type | Amount | Notes |
|---|---|---|
| Building Permit Fee — valuation-based (same Table 18-1 as new construction) | 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) | 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 |
| Use Tax | Assessed on the building valuation using the 58% materials / 42% labor split | Arvada Municipal Code § 98-84; same use-tax split applied to all building permits including ADUs |
Review timeline
~20–30 business days
Typical estimate — confirm current times with the Arvada building department
Inspection process
- 1
Footing / Foundation
Before concrete pour
- 2
Rough Frame
Structural framing, fire separation assembly, egress windows
- 3
MEP Rough-In
Mechanical, electrical, plumbing rough-ins before walls closed; separate HVAC system required from the primary dwelling
- 4
Final
All work complete; Certificate of Occupancy required before occupancy (issuance can take up to 5 business days)
Tips
- As of the lastVerified date, 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 under the currently adopted rules. 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 as of lastVerified this was described as 'still under review' — confirm current status directly with the Building Safety Division before assuming homeowner self-permitting is available.
- 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
- Can a homeowner build their own ADU in Arvada without a licensed contractor?
- As of the lastVerified date, 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 was described by the City as still under review at the time of research — confirm current status with the Building Safety Division before applying.
- What types of ADUs does Arvada allow?
- 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 2026-07-01.
- City of Arvada — Building Safety Division — official building department
- City of Arvada — Accessory Dwelling Units (ADU)
- City of Arvada — Building Code Adoption: Significant Changes (proposed homeowner ADU self-permit change)
- City of Arvada — Building Fee Schedule (Table 18-1 valuation-based schedule; Table 18-2 valuation basis)
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.
Other permits in Arvada
Related guides
Get the AI compliance checklist
Upload your project scope, get a jurisdiction-specific checklist of everything you need. Coming soon.
We only use your email to send permit updates. No spam, unsubscribe anytime. Privacy.