ADUs & DADUs in Marysville
The Svensen Timber Collection — productized, priced, ready.
Marysville is one of the county’s fastest-growing communities, full of families and new construction. It’s ideal ground for value-conscious custom homes and productized ADUs that add space without overbuilding.
Washington's ADU law changes turned the backyard into the most valuable square footage on many lots. Svensen builds detached (DADU) and attached (ADU) dwellings that add real, rentable, livable space — with the same timber craft as our custom homes.
To make the decision simple, we productized it. The Svensen Timber Collection is a set of fixed models with tiered pricing, so you know what you are getting and what it costs before the first drawing.
The Svensen Timber Collection
- Timber 800 — efficient one-bed / studio footprint
- Timber 1000 — one to two bedrooms, full kitchen
- Timber 1200 — two-plus bedrooms, premium finish
- Detached (DADU) and attached (ADU) configurations
- Permit and code navigation under current WA ADU law
- Site work, utility connections, and finish
Marysville’s ADU rules and the critical areas question
Marysville governs accessory dwelling units under Municipal Code Chapter 22C.185, and the chapter carries current state language: a detached unit cannot sit on axles or a chassis, and the city cannot prevent you selling an accessory unit as a condominium separately from the principal structure.
The provision that catches people out is the critical areas exclusion. The ADU provisions do not apply to portions of a lot designated as critical areas or their buffers, or to lots in a watershed serving a potable water reservoir listed as impaired or threatened under the Clean Water Act. Marysville has a good deal of wetland and stream buffer, so on some lots the usable building envelope is much smaller than the lot suggests.
That is worth establishing before design rather than after. A critical areas determination early costs very little and saves redrawing a whole scheme.
- Code
- Marysville Municipal Code Ch. 22C.185.
- Detached units
- Cannot have axles or sit on a chassis. A park model on wheels is not an ADU.
- Condominium sale
- The city cannot prohibit conveying an accessory unit separately as a condominium unit.
- Critical areas
- The ADU provisions do not apply to parts of a lot in critical areas or their buffers.
- Permit intake
- Larger residential and commercial projects upload materials, then notify MsvlPermits@marysvillewa.gov. Land use applications go to LandUseSubmittals@marysvillewa.gov, and staff return an upload link with a file number.
- Small works
- Mechanical, plumbing, electrical and reroof permits go through the online Permit Portal.
Source: City of Marysville — permit applications and forms, verified September 2026. Codes and fee schedules change. Confirm current requirements with the city before relying on this.
Because we mill and engineer in-house, a productized ADU does not mean a cheap one. The Timber Collection ships with real exposed timber that a typical modular or panelized ADU cannot offer at the price.
How the supply chain worksTiered, transparent pricing
Timber 800 / 1000 / 1200 are offered as priced tiers. Pick a model, confirm your site, and we give you a number — no mystery, no open-ended bid. (Current tier pricing available on request.)
From idea to backyard build
Pick a model
Choose the Timber 800, 1000, or 1200 based on your goals and lot.
Confirm the site
We assess setbacks, utilities, and access, and confirm your build is permittable.
Permit & prepare
We handle the ADU permit path and prep the site.
Build & finish
Your unit is built, connected, and finished to the Collection standard.
ADUs & DADUs in Marysville: FAQ
Can I build an ADU or DADU in Marysville?
In most cases, yes. Washington’s 2024–2025 ADU law changes (HB 1337) and Snohomish County’s Ordinance 25-014 expanded ADU rights, allowing up to two units on many lots. We confirm what your specific Marysville lot allows during feasibility.
How much does an ADU cost in Marysville?
Detached ADUs in the Puget Sound typically run roughly $250K–$450K all-in as of 2025. Our Svensen Timber Collection (Timber 800, 1000, 1200) is offered as fixed tiers so you get a clear Marysville number up front instead of an open-ended bid.
How big can my ADU be in Marysville?
Most Washington jurisdictions allow ADUs in the 800–1,200 sq ft range, which is exactly why our Timber Collection comes in 800, 1000, and 1200 — sized to the rules and ready for your Marysville backyard.
Are there parts of my Marysville lot I cannot build an ADU on?
Possibly. The city’s ADU provisions do not apply to portions of a lot designated as critical areas or their buffers, and Marysville has a fair amount of wetland and stream buffer. A critical areas determination early tells you what the real building envelope is, which is much cheaper than finding out after a design is drawn.
Can I put a park model or tiny home on wheels in the back yard?
Not as an accessory dwelling unit. Marysville’s code is explicit that a detached accessory dwelling unit cannot have axles or sit on a chassis. It needs to be a permanent structure on a permanent foundation to be permitted as an ADU.
How do I submit a permit in Marysville?
Small residential work, mechanical, plumbing, electrical and reroofs, goes through the city’s online Permit Portal. Larger residential and commercial projects upload materials and then notify the permit desk by email, and land use applications go to a separate address, with staff returning an upload link and a file number. We handle the submittal on our projects, but it helps to know the process is entirely digital.
Could I sell the ADU separately later?
Potentially. The city cannot prohibit conveying an accessory unit as a condominium unit independently of the principal structure. That is a real option to keep open if you are weighing an ADU as an investment rather than family space, and it is worth raising with your attorney at design stage rather than afterwards.
ADUs & DADUs nearby
Let’s build something that outlasts the mortgage.
Tell us about your project. We’ll tell you what’s buildable, what it costs, and how the supply chain works in your favor.