ADUs & Accessory Dwelling Units in Stevenson, WA
Detached, attached, garage-conversion & junior ADUs.
For adus & accessory dwelling units in Stevenson, the right approach starts with the local housing. Stevenson is part of our wider Southwest Washington service area in Skamania County.
Stevenson sits at roughly 217 feet, on the Clark County plain, in the same wet marine climate as the rest of the Vancouver metro area. PRISM's 1991-2020 climate normals put it at about 75.1 inches of precipitation a year. For adus & accessory dwelling units, that matters most in the parts you never see: indoor humidity has few chances to dry out, so exhaust ventilation sized to the room, a continuous vapor and air-control layer, and properly detailed wet-area waterproofing do more for the life of the work than any finish selection. Stevenson also sits at the western gate of the Columbia River Gorge, where east wind drives rain horizontally into walls that would stay dry elsewhere in the county — so adus & accessory dwelling units here is detailed for wind-driven water, and any James Hardie cladding follows the HZ5 guidance for this zone, all under the Washington State Energy Code.
This page covers adus & accessory dwelling units specifically for Stevenson. For the full service details, see our ADUs & Accessory Dwelling Units page, or explore all the remodeling work we do in Stevenson.
Stevenson is the Skamania County seat, a small town set between the Columbia River and forested hillsides in the heart of the Gorge. Its housing stock is a modest mix of older river-town homes near downtown and newer construction on the surrounding hillsides. Stevenson is known for some of the strongest, most consistent wind in the Gorge, which is a real factor — alongside heavy rainfall and forest moisture — in how we fasten siding, flash windows, and detail roofing here.
From Downtown Stevenson to the rest of Stevenson, we match every adus & accessory dwelling units project to the age, construction, and condition of your specific home rather than a one-size-fits-all spec.
- County
- Skamania County
- Permitting authority
- City of Stevenson — Building Department
- Elevation
- 217 ftCopernicus DEM GLO-90 at the city center
- Annual precipitation
- 75.1 inPRISM 1991-2020 normals, 800 m grid at the city center
- Climate zone
- Marine 4CWashington State Energy Code climate zone
- Detached, attached, and garage-conversion ADUs
- Feasibility review against your lot, setbacks, and utilities
- Full architectural plans and Washington State Energy Code (WSEC) compliance
- Permitting under Washington's statewide ADU law (HB 1337) and local city or county standards
- New electrical, water, sewer, and gas connections or sub-panels
- Kitchens, bathrooms, and complete interior finishing
- Rental, home-office, and multigenerational layouts
- Foundation and framing suited to your site's drainage and soil
- Rain-screen siding and moisture-managed building envelope
- Coordination of the whole project under one contract
- 01
Feasibility & Site Review
We look at your lot size, setbacks, existing structures, and where utilities run, then confirm what type and size of ADU your property and jurisdiction allow under Washington's statewide ADU law and any applicable local ordinance.
- 02
Design & Plans
We develop the floor plan, elevations, and WSEC energy documentation, tailoring the unit to how you'll use it — rental, family suite, or flex space — and to how it sits alongside the main home.
- 03
Permitting
We submit the plans, respond to plan-check comments, and pull the permit for your city or county — City of Vancouver, Clark County, Camas, Washougal, and the other jurisdictions we work in each have their own review process.
- 04
Construction & Utilities
We build the foundation, framing, and shell, run the electrical, plumbing, and any gas or HVAC, and complete the interior — kitchen, bath, flooring, and finishes — coordinating each inspection along the way.
- 05
Final Inspection & Handoff
We complete the final building inspection, walk the finished unit with you, and hand off the space ready to occupy or rent.
Typical timeline: Typically 4 – 9 months. We provide a written schedule after assessing your Stevenson home.
Permit requirements for adus & accessory dwelling units in Stevenson are handled through City of Stevenson — Building Department. Because Washington building rules — including the Washington State Energy Code and local amendments — vary from one jurisdiction to the next, we confirm what your specific address requires and pull the permits and schedule the inspections the scope calls for.
- Building permits are required for structural, electrical, plumbing, and mechanical work
- New construction and most remodels must meet the Washington State Energy Code (WSEC)
Get Your Free ADUs & Accessory Dwelling Units Estimate in Stevenson
Free, no-obligation in-home consultation across Skamania County — we respond within one business day with a fixed-price proposal.
Does Washington make it easier to build an ADU?
Yes. Washington's 2023 statewide ADU law (HB 1337) requires cities and counties in urban growth areas to allow accessory dwelling units on most residential lots and limits how far local rules can go in restricting them, including owner-occupancy requirements. Cities like Vancouver layer their own local ADU standards on top, so we confirm the exact rules for your jurisdiction during feasibility.
How big can an ADU be?
State and local standards set baseline size allowances for ADUs, with the exact maximum depending on your lot size, unit type, and the specific city or county code that applies. We verify the number for your property before design rather than quoting a generic figure.
Do I have to live on the property to have an ADU?
Under Washington's statewide ADU law, jurisdictions generally cannot require the owner to occupy the property to build or keep a standard ADU, which is part of what makes them work as rentals. We confirm how the current rules apply to your specific plan and jurisdiction.
Can an ADU have its own utilities?
Yes. Depending on the design and your existing service, we run dedicated or sub-metered electrical, water, sewer, and gas as needed. For detached units this often means new trenching and connections; garage conversions may be able to tie into existing service. We plan the utility approach during design.
How long does an ADU take to build?
Timelines vary with unit type, site conditions, and the permitting queue in your jurisdiction. A garage conversion is typically faster than a ground-up detached unit. We give you a realistic, written schedule after feasibility and design.
Do I need a permit for adus & accessory dwelling units in Stevenson?
It depends on the scope. City of Stevenson — Building Department sets the requirements for Stevenson, and they can differ from neighboring Washington jurisdictions. We confirm what your project needs before we start and handle the permit and inspection process as part of the job.
Do you handle adus & accessory dwelling units on both older and newer Stevenson homes?
Yes. From Downtown Stevenson to the rest of Stevenson, Stevenson in Skamania County spans a range of housing eras and construction types, and we tailor the adus & accessory dwelling units plan to the age and condition of your specific home rather than a one-size-fits-all template.
How does Stevenson's weather affect adus & accessory dwelling units?
Stevenson averages about 75.1 inches of precipitation a year in PRISM's 1991-2020 climate normals. That is the constraint every detail on a adus & accessory dwelling units project has to answer to: assemblies need a drainage path and the ability to dry, and exterior stages get scheduled around the weather rather than against it. We plan the sequence so nothing is left open to the rain.
What should Stevenson homeowners know before starting adus & accessory dwelling units?
Two things specific to Stevenson. First, permits run through City of Stevenson — Building Department, whose requirements differ from neighboring Washington jurisdictions — we confirm what your address needs before work starts. Second, Stevenson sits at roughly 217 feet, and local drainage and exposure vary enough street to street that we assess your specific lot rather than assuming. Both feed into the written scope and schedule you get before we start.
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