ADU (accessory dwelling unit) Rules and Regulations in Pacific County, WA (2026)

In Pacific County, Washington, whether you can add an ADU (accessory dwelling unit) and how big it can be comes down to your parcel’s Land Use District. The same model can be allowed on one property and constrained on another, so confirm what your specific lot of record allows before you pick a floor plan.

The rules below come from the county’s published Ordinance 194, section 21.F, for unincorporated land. Property inside Long Beach, Ilwaco, Raymond, or South Bend needs that city’s review. For unincorporated urban-growth-area property, confirm how current state ADU requirements affect the county provisions; do not assume the rural unit-count or ownership limits below apply unchanged.

Where ADUs are allowed

The Land Use District sets the requirements your ADU has to meet, including setbacks and height, so eligibility and standards vary across the county.

The county ordinance lists these baseline limits:

• No more than one accessory residential dwelling is permitted per lot of record.
• The ADU must be clearly a subordinate part of an existing residence, and secondary to a principal single-family residential unit.

Size limits

The ADU may be no more than 1,200 square feet.

Setbacks and height

The ADU must follow the minimum setbacks and height limitations of its Land Use District. In addition, an accessory structure should be separated from the primary building by at least five feet, with limited flexibility when certain conditions are met. Confirm the exact setback and height figures for your parcel’s district.

Water, septic, and sewer

The ADU must meet current local and State health code standards for potable water and wastewater disposal. On rural parcels that typically means confirming the property can support water and septic capacity for an additional dwelling before you commit to a plan.

Ownership and rental rules

The published county ordinance includes these conditions:

• The accessory dwelling and the land it is located on cannot be sold separately from the primary residential dwelling.
• On residentially zoned property with a primary dwelling and an ADU, only one residential structure may be licensed as a vacation rental. This is not automatic rental approval; the district must allow it and the licensing requirements still apply.

For an urban-growth-area parcel, obtain current guidance before relying on the separate-sale restriction. State urban ADU protections distinguish condominium conveyance from subdivision of the land. An ADU permit itself does not approve a land division.

Permits and process

Ordinance 196, adopted in 2025, is the current land-use processing ordinance. Its table classifies an allowed or accessory use review as Type I, an administrative process without notice or comment. The older procedural cross-reference in Ordinance 194 does not replace Ordinance 196. A project that also needs shoreline, critical-area, variance, or other approvals can trigger additional review; ask DCD to identify the combined permit path.

Confirm permit fees directly with Pacific County before you budget.

What Wolf checks first

For a Pacific County ADU, we usually want to know:

1. What Land Use District applies to the parcel, and what setbacks and height that district sets?
2. Is there an existing lawful primary residence the ADU can be subordinate to?
3. Can the property meet local and State health code for potable water and wastewater?
4. Does the design stay within the 1,200 square foot cap and the five-foot separation from the primary building?
5. How will the unit be used: long-term rental, family dwelling, or vacation rental within the one-per-lot limit?
6. Can a modular unit be delivered, staged, and set on the site safely?

Modular homes in Pacific County

Wolf homes are factory-built modular structures (our factory is at 607 SE Eaton Blvd, Battle Ground WA 98604). Your property still needs local site work, utilities, a foundation, and inspections, and Pacific County has to approve that placement work.

For delivery routes and how Pacific County compares with Grays Harbor and the Olympic Peninsula, see ADUs and beach cabins on the Washington coast.

Start with your address

Send us the property address and intended use, and we will check the Land Use District, setbacks, water, wastewater, and model fit.

Get a free Wolf property evaluation.

This is general information, not legal advice. Confirm current rules, fees, and application requirements with Pacific County before you build.