ADU / DADU Construction
DADU & ADU Construction | Seattle & Eastside
Washington State now allows up to 2 ADUs per lot. Add a DADU to generate rental income, house family, or increase your property value. RZO Construction handles design, permits, and construction.
What We Build
ADU & DADU Services
Detached ADUs (DADUs)
Garage Conversions
Backyard Cottages
ADU Permitting Assistance
Why Build a DADU
The Benefits of Adding an ADU
Rental Income Potential
A DADU can generate $1,500–$3,000+/month in rental income in the Seattle metro area.
Increase Property Value
A permitted DADU significantly increases your home's appraised value and resale appeal.
House Family Members
Keep aging parents or adult children close in a private, comfortable space on your lot.
WA State 2025 ADU Laws
Washington State now allows up to 2 ADUs per lot and has removed owner-occupancy requirements in most cities.
Feasibility Checker
Check Your DADU Eligibility
Answer a few quick questions to see if your property may qualify for a DADU.
Check Your DADU Eligibility
Answer a few quick questions to see if your property may qualify
Where is your property located?
FAQs
ADU Questions Answered
How many ADUs can I build in Washington State?
As of 2025, Washington State allows up to 2 ADUs per lot on single-family properties. This is a significant expansion from previous rules.
Do I need a permit for a DADU?
Yes — a full building permit is required, including architectural plans, a site plan, and all required inspections. RZO handles the entire permitting process for you.
How long does it take to build a DADU?
Typically 6–12 months total, including the permitting phase (4–8 weeks) and construction (4–6 months) depending on size and complexity.
Can I rent out my DADU?
Yes — Washington State has removed the owner-occupancy requirement in most cities, meaning you can rent out your DADU even if you don't live on the property.
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Your Home?
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