Camas, WA ADU (accessory dwelling unit) Rules and Regulations (2026)

Camas is in Clark County, a short haul from the Wolf factory in Battle Ground. Being close doesn’t settle who reviews the permit. A Camas mailing address can sit inside city limits or on unincorporated land that files with the county.

For Wolf’s services in the city, see ADU (accessory dwelling unit) builder in Camas. For county context, see Clark County ADU rules; for the state statute, Washington ADU laws; and for pricing, the Washington ADU cost guide.

This is not legal advice. Confirm the current Camas Municipal Code and packet when you file.

City of Camas or Clark County first

Pull the parcel on Clark County GIS. City limits, zone, and taxlot are there. If the lot is inside Camas, you file with the city’s Community Development department. If it isn’t, you file with the county even when the mail says Camas.

Downtown blocks, Prune Hill subdivisions, and properties near Lacamas Lake can have very different site conditions. Slope and trees may further limit the buildable area. The detached side and rear numbers below come from CMC 18.27. The front setback, lot coverage, and critical areas still follow the zone.

What Camas changed in 2025

In 2025 the Camas City Council adopted Ordinance No. 25-025, updating portions of the Camas Municipal Code to comply with Washington laws intended to expand housing choices. The city’s published materials describe the practical result:

• Lots with one primary dwelling and no middle housing may have up to two ADUs.
• Configurations can be two attached, two detached, one of each, or a unit inside the house plus a conversion of an existing accessory structure.
• Detached ADUs may be one building with two units or two separate structures, if the rest of the development still complies.

Being allowed two ADUs doesn’t mean a given backyard can fit two factory modules. Access, parking, utilities, critical areas, and existing structures still decide which model works.

ADUs count toward the middle-housing unit count in CMC Chapter 18.25. Two ADUs are allowed only when the lot has one principal dwelling and no middle housing. A lot that already has two units, such as a duplex, generally cannot add an ADU under that rule.

State urban ADU protections and their exceptions are summarized in the Washington ADU laws guide. The permit itself still goes through Camas.

What an ADU is in Camas

An accessory dwelling unit is a complete secondary residence on the same lot as a primary home: kitchen, bath, sleeping, living, its own entrance, heat and power. A bedroom addition, a detached office, or an RV doesn’t count.

Under the current city rules an ADU may sit inside the house, attached to it, or as a separate detached structure. Wolf builds detached modular dwellings. Converting existing space is a separate design and permit.

Size, height, and setbacks

The city handout lists a 1,000-square-foot maximum per ADU, excluding garages. CMC 18.27 also lets the Community Development Director allow more floor area when an ADU takes an entire single floor inside an existing house or accessory structure, so that existing floor can be used.

Height is the place the handout and the code don’t match. The handout lists a 25-foot height limit. CMC 18.27 limits a detached ADU to 24 feet, and it uses the zone’s height limit for an internal conversion or an addition to the house. The handout tells you to read Chapter 18.27 for the full standards. Plan a detached unit to 24 feet unless Camas staff tells you they are applying the handout number.

Setbacks in that same section:

• The ADU has to meet the front-yard setback for the property.
• A detached ADU stays at least 5 feet from a side lot line and 5 feet from a rear lot line.
• On a corner lot, the side along the flanking street is 10 feet.
• If the rear lot line abuts a public alley, a detached ADU does not need a rear setback from that line.

Those distances are measured from the property lines. A fence is not the line. Easements, critical-area buffers, and the space the fire code wants between buildings can shrink the pad further. Slope and trees around Prune Hill and Lacamas Lake do the same.

Parking

CMC 18.27 requires one off-street parking space for the ADU, on top of the parking required for the other homes on the lot. That extra space is not required when the ADU is within one-half mile of a major transit stop. The code’s definition of a major transit stop covers high-capacity transit funded under chapter 81.104 RCW, commuter rail, rail or fixed guideway, and bus rapid transit. Driveway width, the existing garage, and the path a module has to travel still have to work when the extra stall is waived.

Water, sewer, and separate ownership

An ADU in the city connects to public water and public sewer. It may share the house’s water and sewer when the meter, the service lines, and any STEP or STEF tank are sized for both. If the ADU will be owned separately, it needs its own utility services.

The code allows an individual ADU to be conveyed as a condominium under Chapter 64.34 RCW, or divided into unit lots. That is a different application from an ADU that stays on the original parcel. Talk with the city, a surveyor, and a land-use attorney before you plan on selling the unit by itself.

Design and conversions

A detached ADU has to pick at least two architectural elements from the principal dwelling. CMC 18.27 lists roof-overhang depth, roof pitch, trim size and style, window proportions and color, primary paint color, roofing material and color, porch or entry details, and primary siding. The unit also has to limit overlook onto the neighbor: stagger windows and doors, keep upper-level windows and decks off the shared lot line, and add landscaping where screening is what makes the placement work.

A conversion of an existing accessory structure, such as a detached garage, may stay nonconforming to the current setback or lot coverage. It still has to meet building, fire, health, and safety codes. Ceiling height, insulation, the foundation, and fire separation decide whether a conversion is simpler than a new module.

How a factory-built ADU is treated

A Wolf home is modular. It is not a HUD (the federal standard for manufactured homes) manufactured home. Washington L&I reviews the factory plans and oversees factory inspections; the building must have its L&I insignia before shipping. Local review covers placement, foundation, utility connections, and applicable site inspections.

Camas city lots are usually connected to sewer. A property with a Camas mailing address may still be unincorporated and use septic, which requires review by Clark County Public Health.

The permit

You need a building permit. The building department assigns the address, with fire department approval. The ADU cannot be occupied until the city issues a certificate of occupancy. Depending on the lot, the packet can also include a site plan, structural plans, the state modular approval, electrical, plumbing, and mechanical permits, utility review, stormwater, erosion control, critical areas, fire access, and a driveway or right-of-way permit.

Older city and county handouts still circulate. Use the current code and the city’s middle-housing page when you file. County rules, if GIS puts you outside the city, are in the Clark County ADU guide.

What to have ready

• The parcel on Clark County GIS, and whether it is inside city limits
• The zone, and a sketch of the house, the driveway, and the proposed pad against the setbacks above
• Utility records: meter size, sewer or STEP/STEF, and whether you want separate ownership
• How you will use the unit

Send the address. If you already have a survey or a land-use letter, say so in the message. We’ll confirm city versus county before we lay out a permit path.