Guides & resources
Guides to building an ADU in the Northwest
ADU rules, costs, financing, and construction for property owners in Washington and Oregon.
Washington ADU Laws in 2026: A Practical Guide for Homeowners
How HB 1337 changed ADU rules statewide, plus the real-world details for Clark County and Vancouver WA: size, setbacks, septic, fees, and modular permitting.
Clark County, WA ADU Rules and Regulations (2026)
Clark County ADU rules in 2026: city versus unincorporated property, urban growth areas, rural ADUs, official GIS, and county guidance.
Oregon ADU Rules in 2026: A Practical Guide for Homeowners
How Oregon's statewide ADU law, system development charges, and the BCD modular program work in 2026, with Portland metro and Southern Oregon context.
ADU Cost in Washington: Home Prices and Standard Setup
Washington ADU home prices start at $85,500 for Model K. Compare standard setup, exclusions, permitting, delivery and property-specific work.
Camas, WA ADU Rules and Regulations (2026)
Camas ADU rules in 2026: city versus Clark County, Ordinance 25-025, the 1,000 sq ft cap, 24-foot detached height, 5-foot setbacks, parking, and sewer.
How to Finance an ADU in the Pacific Northwest (2026)
Compare cash, home equity, renovation loans, and construction financing for a Washington or Oregon ADU, including factory payment timing and lender questions.
ADU Cost in Oregon: Home Prices and Property Costs, SDCs, and Portland Context
Wolf ADU cost ranges for Oregon, including starting home prices, typical turn-key projects, permitting, delivery, system development charges, and site work.
Lane County, OR ADU Rules: What to Check Before You Build
A practical Lane County ADU guide: the rural RR-zone ADU standards in Lane Code 16.290, fire and evacuation paperwork, wells and septic, historic-home conversions, and city-vs-county review.
Benton County, OR ADU Rules: A Practical Homeowner Checklist
How to think about Benton County ADU rules in 2026: UGB location, county-vs-city jurisdiction, size limits, utilities, access, septic, and modular delivery.
ADU Feasibility Checklist: 16 Questions to Answer Before You Build
A free, printable checklist for Washington and Oregon homeowners: zoning and ADU size limits, covenants, setbacks, delivery and fire access, water, sewer or septic, power, agency fees, budget, and timeline — before you commit to a design.
Clackamas County, OR ADU Rules (2026): Urban, Rural, and City Lots
Clackamas County ADU rules for 2026: ZDO 839 urban size limits, the rural 2-acre, 900 sq ft, 100-foot path, excluded farm and forest zones, and which city reviews your lot.
Multnomah County, OR ADU Rules (2026): City or County Review?
Multnomah County ADU rules for 2026: which city or county office reviews your lot, unincorporated standards (800 sq ft, 7 to 20 feet from the house), septic, taxes, and Portland waiver context.
Washington County, OR ADU Rules (2026): Urban, Rural, and City Lots
Washington County ADU rules for 2026: county urban ADU limits, the new rural ADU program in AF-5, AF-10, and RR-5, septic and water letters, and which city reviews your lot.
Prefab ADU vs Stick-Built vs Manufactured Homes
Factory modular ADUs vs on-site stick-built vs HUD manufactured homes: code, crew, schedule, and Wolf’s published cost ranges.
Polk County, OR ADU Rules: Urban and Rural Site Checks
Polk County ADU planning under the June 2026 update: urban floor-area limits, rural eligibility, water and wastewater checks, and modular model fit.
Chelan County, WA ADU Rules (2026): City or County?
How to start an ADU in Chelan County: Wenatchee and Chelan city limits versus unincorporated county review, and what Wolf checks before a Battle Ground build.
Cowlitz County, WA ADU Rules (2026): City or County?
Cowlitz County ADU planning: Longview, Kelso, Castle Rock, Kalama, and Woodland each file separately from unincorporated county land. What to confirm before a Wolf build.
Lewis County, WA ADU Rules (2026): City or County?
Lewis County ADU planning for Centralia, Chehalis, and unincorporated land: which office reviews the lot, and what Wolf checks on an I-5 delivery from Battle Ground.
Skamania County, WA ADU Rules (2026): County, City, or the Gorge?
Skamania County ADU planning: city versus county review, and why Columbia River Gorge scenic-area rules can matter more than a statewide ADU statute.
Douglas County, OR ADU Rules (2026): City or County?
Douglas County, Oregon ADU planning: Roseburg and Reedsport city limits versus county review, I-5 distance from Battle Ground, and what to confirm first.
Jackson County, OR ADU Rules (2026): City or County?
Jackson County ADU planning for Medford, Ashland, and unincorporated land: which office reviews the lot, and what a long I-5 delivery from Battle Ground requires.
Clallam County, WA ADU Rules and Regulations (2026)
A practical Clallam County ADU guide: where ADUs are allowed, size limits, water and septic rules, owner-occupancy, parking, and the county permit process.
ADU Rules in Clatsop County, OR: What to Check
A practical Clatsop County, OR ADU guide: how zoning, lot type, utilities, and site constraints shape eligibility, and what Wolf verifies on your exact parcel first.
ADU Rules in Deschutes County, OR (2026)
A practical Deschutes County ADU guide: which rural zones qualify, the 2-acre rule, 900 sq ft cap, the 100-foot rule, fire access specs, septic/water, and rental limits Wolf checks first.
ADU Rules and Regulations in Columbia County, OR (2026)
Columbia County, OR ADU rules for 2026: rural lot size and floor-area limits, distance from the main house, water and septic, plus city-vs-county jurisdiction.
ADU Rules in Grays Harbor County, WA (2026)
What to check before building an ADU in Grays Harbor County, WA: zoning eligibility, rural septic and well limits, utility standards, and permits. Wolf verifies your parcel.
ADU Rules and Regulations in Jefferson County, WA (2026)
Jefferson County, WA ADU guide: where ADUs are allowed, size cap, setbacks, water and septic, owner-occupancy, and parking — plus a free Wolf parcel check.
ADU Rules and Regulations in Island County, WA (2026)
Island County, WA ADU planning after the June 2026 code adoption: size, placement, urban and rural differences, permit availability, water, and septic.
King County, WA ADU Rules and Regulations (2026)
King County ADU rules for unincorporated land in 2026, plus Kirkland’s city rules: two ADUs, the 1,200 sq ft cap, shoreline limits, parking, and the registration covenant.
ADU Rules in Kittitas County, WA: What to Check
Kittitas County ADU planning: rural administrative permits, the 1,500-square-foot limit, separate urban rules, water, septic, and access.
Kitsap County, WA ADU Rules and Regulations (2026)
Kitsap County WA ADU guide: size limits inside vs outside UGAs, owner-occupancy, parking, the rural conditional use permit, pre-approved plans, utilities, and the permit path Wolf checks first.
ADU Planning in Klickitat County, WA (2026)
Plan a Klickitat County ADU around the current adopted rules, water and septic approval, access, and the county's 2026 code update.
ADU Rules and Regulations in Lincoln County, OR (2026)
Lincoln County, OR ADU rules: Urban Growth Boundary eligibility under Ordinance #507, the 800 sq ft size cap, setbacks, septic, short-term rental limits, and permits.
ADU Rules and Regulations in Linn County, OR (2026)
Linn County, OR ADU guide: rural residential eligibility, 900 sq ft limit, 100-ft siting, septic and water standards, rental rules, and what Wolf verifies first.
ADU Rules and Regulations in Marion County, OR (2026)
Marion County, OR ADU guide: where ADUs are allowed in urban and rural zones, size and height limits, setbacks, rental rules, parking, and the permit path.
ADU Rules and Regulations in Mason County, WA (2026)
Mason County ADU rules for rural land: eligibility, size limits, setbacks, septic and well approval, owner-occupancy, parking, and the permit path Wolf checks first.
ADU Rules and Regulations in Pacific County, WA (2026)
A practical Pacific County, WA ADU guide: Land Use District eligibility, the 1,200 sq ft cap, setbacks, vacation-rental limits, the Type I permit path, and what Wolf checks first.
Pierce County, WA ADU Rules and Regulations (2026)
Pierce County ADU rules for unincorporated land in 2026: two ADUs in the UGA and one outside, 1,000 vs 1,250 sq ft caps, setbacks, height, parking near transit, and septic review.
Snohomish County, WA ADU Rules and Regulations (2026)
Snohomish County ADU rules for unincorporated land in 2026: two ADUs in urban zones, one in rural zones, the 1,200 sq ft cap, rural lot-size limits, parking, and water and septic proof.
ADU Planning in Skagit County, WA (2026)
Skagit County ADU planning: identify city or county jurisdiction, confirm adopted zoning, and check water, septic, floodplain, and delivery access.
ADU Rules and Regulations in San Juan County, WA (2026)
San Juan County ADU planning: rural detached-unit eligibility, size and parcel limits, shared utilities, rental restrictions, and island delivery.
Spokane County, WA ADU Rules and Regulations (2026)
Spokane County ADU rules in 2026: rural attached and detached standards, the urban conditional-use path, the December 2026 state deadline for urban ADU rules, and septic review.
ADU Rules and Regulations in Tillamook County, OR (2026)
A Tillamook County, OR ADU guide: eligible zones, coastal constraints, utilities, rental rules, and what Wolf verifies on your exact parcel first.
ADU Rules and Regulations in Wasco County, OR (2026)
Wasco County ADU guide: qualifying rural residential zones, the 900 sq ft and 2-acre rules, deed restrictions, fire and septic requirements, and what Wolf checks first.
ADU Planning in Wahkiakum County, WA (2026)
What to confirm for a Wahkiakum County ADU: permission for another dwelling, water and wastewater approval, setbacks, shoreline, floodplain, and access.
Thurston County, WA ADU Rules and Regulations (2026)
Thurston County ADU rules after the December 2025 update: one rural ADU with a 1,000 sq ft detached cap, two ADUs in UGAs, the 100-foot rule, shared driveways, and water review.
ADU Rules and Regulations in Yakima County, WA (2026)
Yakima County ADU planning: county versus city jurisdiction, housing classification, legal water supply, sewer or septic approval, and site access.
Whatcom County, WA ADU Rules and Regulations (2026)
Whatcom County ADU rules after the December 2025 update: two ADUs on eligible UGA lots, rural lot-size minimums, the 1,248 sq ft cap, owner occupancy outside UGAs, and plat limits.
ADU Rules and Regulations in Yamhill County, OR (2026)
A practical Yamhill County ADU guide: where ADUs are allowed inside and outside UGBs, the 900 sq ft cap, the 2-acre rural rule, and what Wolf checks first.
Costs and comparisons
Dedicated cost, factory-vs-stick, and competitor pages
Use these guides to compare costs, construction methods, and builder services before requesting a property review.
Plan your property budget
Compare home starting prices, delivery and setup, and the work your property may need.
Learning center
Find the right starting point for laws, costs, models, financing and owner resources.
Building an ADU in Washington
How Wolf employees handle a Washington ADU project, from property review through installation.
Wolf housing options
Compare backyard, family, primary-home and community uses before choosing a floor plan.
ADU cost in Washington
Typical costs, Clark County site-work considerations, and links to Battle Ground and Vancouver.
ADU cost in Oregon
Typical costs, system development charges, and Portland’s 800 sq ft limit.
Clark County ADU rules (2026)
City vs unincorporated, UGA vs rural/RADU, with official GIS maps and county handouts.
Camas ADU rules (2026)
City vs Clark County, including Ordinance 25-025 and the rules for up to two ADUs.
Prefab ADU vs stick-built
A side-by-side table of factory modular, on-site stick-built, and HUD manufactured homes.
Wolf vs RG ProBuilders
How factory modular construction compares with on-site building in Battle Ground.
Wolf vs MyADU
Factory modular vs custom design-build in the Portland–Vancouver metro.
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