Clark County staff outline ADU rules, fees and permit steps at public learning lab

Clark County Community Development permit technicians held a public learning lab to explain new and existing rules for accessory dwelling units (ADUs), including differences between urban and rural ADUs, impact-fee incentives, permit intake and utility requirements.

County staff said rural ADUs must be attached to the primary residence, while urban ADUs may be detached or attached. County presenters said square-footage limits differ by zone: most urban ADUs are capped at 1,000 square feet, but a single ADU may be up to 1,500 square feet on lots of at least 20,000 square feet; where two ADUs are allowed the combined maximum is 2,000 square feet. Staff also said manufactured homes built after June 15, 1976, may qualify as ADUs if they meet state standards and permitting requirements.

The county emphasized that every ADU requires utility connections and approvals from water and sewer purveyors. Owners on septic must obtain approval from the Clark County Health Department; county staff warned that properties within about 300 feet of a public sewer line may be required to extend the sewer to the property’s furthest lot line at the owner’s expense. County staff also explained that Clark County assesses reduced impact fees for ADUs: 25% of standard road, parks and school impact fees for qualifying ADUs; guest houses and temporary hardship placements pay no impact fees.

Why this matters: ADU rules affect homeowners’ options for on‑site housing, rental potential and the cost of adding living units. Attachment rules in rural zones are controlled by state growth-management requirements that the county must follow, staff said, and utility hookups or septic upgrades can be a substantial cost for property owners.

Major details presented

- Attachment and state law: County presenters said rural ADUs must be attached to the primary residence either by a common wall or a breezeway; that restriction reflects state Growth Management Act interpretations intended to avoid unplanned increases in rural density. Urban ADUs may be detached.

- Size and height limits: County staff said urban ADUs generally are not to exceed 1,000 square feet; lots of at least 20,000 square feet may host a single ADU up to 1,500 square feet and, where two ADUs are permitted, a combined limit of 2,000 square feet. The county said urban height limits for ADUs were recently adjusted to 24 feet; attached rural ADUs may have higher height allowances (county staff cited 35 feet for some rural attachments).

- Guest houses and temporary hardship placements: Guest houses and hardship placements differ from ADUs. Staff said guest houses and hardship placements do not allow a full stove or standard kitchen hookups and have no square-footage cap; guest houses and temporary hardship placements pay no impact fees. Hardship placements are limited to two-year terms with renewal rules.

- Utilities and septic: Every ADU requires approved connections for water and sewer from the purveyors. For properties served by septic, owners must obtain county health-department approval and may need system upgrades to serve additional units.

- GIS, zoning and setbacks: Staff demonstrated the county GIS site where property owners can check zoning designations, lot size, and service providers. The county summarized setback guidance: many urban zones use smaller setbacks (for example, 5-foot side setbacks and a 10-foot rear setback in several urban residential zones), while rural setbacks may be significantly larger (county staff cited typical rural front setbacks around 50 feet and side/rear setbacks around 20 feet). Staff said exact setbacks depend on the property's zoning and encouraged one-on-one permit center appointments for parcel-specific questions.

- Permitting workflow and resources: Applicants apply through the county’s permit intake (ADU permit) and the presenters reviewed the county’s project-docs and LMS platforms for uploading plans and naming conventions. Permit center staff said 30-minute Q&A appointments are available, in person or via Teams, at no cost, and the permit center phone line and posted resources are available Monday–Friday during posted hours.

Public questions and county responses

During a lengthy Q&A, attendees asked about placing ADUs in front yards, converting existing garages, parking requirements, HOA restrictions, preapproved plans (the county said it does not offer preapproved ADU plans), and how ADUs affect tax assessment. County staff said garage conversions can qualify if the structure meets building and fire requirements; parking for an ADU must be shown on the plot plan. Staff deferred assessor-related valuation questions to the Clark County assessor. On HOA rules, staff said county zoning and permitting do not override private CC&Rs and suggested owners consult their HOA documents.

County staff also fielded questions about guest houses in agricultural or forest zones; they said some zones require conditional-use permits and land-use approval before a guest house may be permitted.

Next steps and contact information

Presenters encouraged property owners to use the county GIS and the Community Development website for forms and guidance, schedule a free 30-minute Q&A appointment with a permit technician for parcel‑specific review, and contact the Clark County Health Department for septic approvals. Staff announced upcoming learning-lab topics and noted the next session, on commercial fire safety inspections, scheduled for May 15.

Ending

County presenters closed by thanking attendees and reminding them that permit center staff answer questions by phone and email during posted hours and that in-person Q&A appointments are available on Tuesdays and Thursdays.