Can I build a backyard home in Marysville?
Since 2023, Washington law lets most city lots hold up to two more homes. Marysville writes its own rules on top. Here’s what the code says, in plain English — and a free report on what may fit on your lot.
What Marysville allows.
The headline standards. Open any card for the full wording and the code section.
ADUs per lot2 per single-family lotFull wording
2 per single-family lot
Max size1,000 sq ft or 50% of the residence, whichever is greater, capped at 1,400 sq ftFull wording
1,000 sq ft or 50% of the residence, whichever is greater, capped at 1,400 sq ft; minimum 200 sq ft
Max height30 ftFull wording
30 ft
Front setbackThe zone’s front setback (MMC 22C.010.080)Full wording
Per MMC 22C.010.080
Side setback5 ft (10 ft on a side street)Full wording
5 ft; side street 10 ft (15 ft on an arterial)
Rear setback15 ft (10 ft if one story)Full wording
15 ft; 10 ft if one story
Lot coverageThe zone’s coverage limit (MMC 22C.010.080)Full wording
Per MMC 22C.010.080
ParkingPer the middle-housing parking table (MMC 22C.130.030)Full wording
Per the middle-housing table at MMC 22C.130.030
Where a city figure reads stricter than the state floor (RCW 36.70A.681), the floor may control — the report flags it for your parcel.
Living there, selling it, plans, time and fees.
Each answer is the code’s own wording, with the section it comes from. “Not published yet” means the city hasn’t posted a figure — the report asks the city, not the internet.
Are backyard homes allowed?
Yes
Minimum lot size
The lot must meet the minimum for the principal unit
Do you have to live there?
No — none required
Can it be sold on its own?
Yes — state language adopted
Pre-approved plans
None found
How long the city takes
not published yet — ask the city
Impact fees
not published yet — ask the city
The code is half the answer. Your parcel is the other half.
Lines and easements
Where the lot lines really are, which setbacks apply on each side, and whether a utility or access easement takes the corner you had in mind.
Critical areas and slope
Steep slopes, wetlands and streams come with buffers that no citywide number shows. The report reads the county’s maps for your parcel.
Sewer, septic, water, trees
Whether sewer reaches the lot or it’s on septic, where the water service is, and which trees a city protects — the things that decide where a unit can actually go.
What Marysville allows, what could fit on your lot, and a planning cost range. If something won’t fit, the report says so — and shows what might.
Where this page comes from.
Read from the Marysville municipal code and the city’s own pages on September 15, 2026. The same table feeds the HousUp report, so the report and this page never disagree. Cities amend their codes; before you design anything, confirm the current wording with the city.
Find out what your property could become.
Type your address. Within a few hours: what Marysville allows, what could fit, and a planning cost range. Free, no obligation.