ADUs & DADUs in Mukilteo
The Svensen Timber Collection — productized, priced, ready.
Mukilteo’s waterfront bluffs and Sound views demand homes engineered for the site — daylight basements, view-forward great rooms, and structure that holds up to a marine climate. Exposed timber feels right at home here.
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
What you can build on a Mukilteo lot
Mukilteo Municipal Code Chapter 17.30 governs accessory dwelling units, and the standards are more generous than most homeowners expect when they first look into it.
The practical effect is that a Mukilteo lot can carry two units behind the main house, each up to a thousand square feet, without the frontage work that used to make small projects uneconomic.
- Units per lot
- Up to two accessory dwelling units on a single-family residential lot.
- Size ceiling
- Up to 1,000 sq ft. A unit over 1,000 sq ft is not treated as an ADU.
- Frontage
- No new frontage improvements are required to install an ADU.
- Driveways
- One driveway per lot unless the director approves an exception.
- Accessibility
- Setback encroachments may be allowed without a variance for features such as ramps.
- Exclusion
- ADUs are not allowed in cottage housing developments.
Source: Mukilteo Municipal Code Ch. 17.30, 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 Mukilteo: FAQ
Can I build an ADU or DADU in Mukilteo?
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 Mukilteo lot allows during feasibility.
How much does an ADU cost in Mukilteo?
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 Mukilteo number up front instead of an open-ended bid.
How big can my ADU be in Mukilteo?
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 Mukilteo backyard.
Can I build two ADUs on one lot in Mukilteo?
Yes. Mukilteo Municipal Code Chapter 17.30 allows up to two accessory dwelling units on a single-family residential lot, attached, detached, or a combination. Each can be up to a thousand square feet. Anything larger is no longer classed as an ADU, which changes how it is reviewed.
Will I have to add a sidewalk or widen the road for a Mukilteo ADU?
No. The code states that no new frontage improvements are required to install an ADU. That removes a cost that used to sink a lot of small backyard projects. You are still limited to one driveway per lot unless the director approves an exception.
My lot is on the bluff. Does that change what I can build?
It changes how it gets engineered rather than whether it is possible. Slope, drainage and soil all drive the foundation design on Mukilteo’s waterfront side, and a geotechnical report early is far cheaper than a redesign later. We would rather tell you what the site demands before you fall in love with a drawing.
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.