ADU Questions & Answers: Vancouver, WA

Can I build an ADU in Vancouver?

Yes, ADUs are allowed in Residential single-family zones in Vancouver, WA. The maximum size for a detached ADU is 1,000 sq ft gross floor area. Attached ADUs can be up to 1,000 sq ft gross floor area. Vancouver has an ADU-friendliness score of 7/10. Check our full Vancouver ADU rules page for complete zoning details.

How much does it cost to build an ADU in Vancouver?

ADU construction in Vancouver typically costs $135,000-$270,000. The cost per square foot averages $130-$260. Garage conversions are more affordable at $65,000-$155,000, while prefab ADUs cost $95,000-$220,000. Permit fees add $1,900-$3,200 to your budget. See our detailed Vancouver ADU cost guide.

What are the ADU size limits in Vancouver?

Detached ADUs in Vancouver can be up to 1,000 sq ft gross floor area. Attached ADUs are limited to 1,000 sq ft gross floor area. Junior ADUs (JADUs) have a cap of N/A (Washington does not use a separate JADU category). Maximum height is 35 feet. You are allowed up to Up to 2 ADUs per lot on a qualifying lot.

What are the setback requirements for ADUs in Vancouver?

Rear setback: Confirm with Vancouver Planning (VMC 20.810.040). Side setback: Confirm with Vancouver Planning (VMC 20.810.040). Front setback: Confirm with Vancouver Planning (VMC 20.810.040). Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.

Do I need parking for an ADU in Vancouver?

Not required within 1/2 mile of a major transit stop (per Washington HB 1337); Confirm with Vancouver Planning otherwise. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.

Is owner-occupancy required for ADUs in Vancouver?

Not required. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.

How long does it take to get an ADU permit in Vancouver?

The ADU permit review timeline in Vancouver is typically 45-65 days. Plan check: 2-3 weeks. Pre-approved plans availability: Available.

How much can I rent my ADU for in Vancouver?

Average ADU rental income in Vancouver: 1-bedroom units rent for $1,250-$1,700/month, 2-bedroom units for $1,600-$2,300/month. Short-term rentals: Permitted with license. Expected ROI: 7-9% annual return.

What is the minimum lot size for an ADU in Vancouver?

The minimum lot size for an ADU in Vancouver is None - an ADU may be established on any legally established lot (VMC 20.810). This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.

Can I convert my garage into an ADU in Vancouver?

Garage conversions are one of the most popular and affordable ADU options. In Vancouver, a garage conversion typically costs $65,000-$155,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.

About this information: This page is an informational summary of publicly available regulations - it is not legal, financial, or professional advice, and it is not a substitute for confirming requirements with your local planning department. Rules change frequently; always verify current requirements before designing, budgeting, or building. Last verified: 2026-07-07. Contractors we introduce are independent businesses - verify license and insurance directly before hiring. Spotted an error? Tell us - we verify against primary sources and correct quickly.