08/28/2026
THINKING ABOUT BUYING A PROPERTY WHERE YOU CAN ADD AN ADU OR DADU?
This is becoming a BIG conversation with buyers throughout Snohomish County.
Whether you’re thinking about creating a home for aging parents, adult children, rental income, or simply adding long-term value to your property, buying a home with the ability to add an ADU or DADU can be a great strategy.
But here’s the important part:
👉 Just because a property has a big backyard or acreage DOES NOT automatically mean you can build another home on it.
There are several things we need to look at BEFORE you buy:
✅ Is the property inside a city or unincorporated Snohomish County?
✅ What is the zoning?
✅ Is it inside or outside the Urban Growth Area?
✅ How many ADUs are allowed?
✅ How large can the ADU/DADU be?
✅ What are the front, side and rear setbacks?
✅ Is there enough lot coverage/buildable area?
✅ Are there wetlands, streams, steep slopes or other critical areas?
✅ Is the property on sewer or septic?
✅ If it’s septic, can the system support another dwelling/bedrooms?
✅ Is there adequate water service?
Those questions can completely change whether a property works for what you’re trying to accomplish.
The good news is that Washington’s ADU laws have changed significantly, and many properties now have more options than they did just a few years ago.
For example:
🏠 Everett allows attached and detached ADUs in most residential areas, with ADUs generally under 1,000 sq ft, and up to two ADUs can receive ADU treatment on a lot.
🏠 Marysville allows up to two ADUs with a single-family home. ADUs can generally be up to 1,000 sq ft or 50% of the primary home’s floor area, whichever is greater, up to a maximum of 1,400 sq ft. Typical DADU side setbacks are 5’, with rear setbacks generally 15’, although certain one-story DADUs can be as close as 10’.
🏠 Lake Stevens allows two ADUs in residential zones, either attached, detached or a combination, subject to the property’s development standards.
🏠 Mukilteo allows ADUs up to 1,000 sq ft, with setbacks generally determined by the underlying zoning.
🏠 Arlington, Stanwood, Monroe, Snohomish, Edmonds, Lynnwood, Mill Creek and other cities each have their own development standards that need to be checked.
🌲 RURAL SNOHOMISH COUNTY is different.
If you’re looking at acreage outside the Urban Growth Area, don’t assume the same ADU rules that apply to a city lot will apply there.
Lot size, zoning, septic, water, critical areas and the location of the existing home can all affect whether a detached ADU is feasible.
Snohomish County has also introduced pre-approved ADU plans, which may make the permitting/design process easier for qualifying properties.
⭐ THIS IS WHERE I CAN HELP.
If your goal is to buy a property where you can eventually build a second living space, tell me that BEFORE we start looking.
Instead of simply searching for a house, I can help you look for properties with ADU/DADU potential and investigate the zoning and jurisdiction before you get too far down the road.
Whether you’re looking in:
📍 Arlington
📍 Marysville
📍 Lake Stevens
📍 Snohomish
📍 Everett
📍 Monroe
📍 Stanwood
📍 Edmonds
📍 Lynnwood
📍 Mill Creek
📍 Mukilteo
📍 or rural Snohomish County…
I can help you identify properties that may fit your goals and point you toward the appropriate city or county department to verify feasibility.
📲 Thinking about buying a home with ADU/DADU potential?
Send me a message with the word “ADU” and tell me what area you’re interested in.
I’ll help you start looking for the right property.
Harry Parker |
