Current Regulations for Rural Accessory Dwelling Units (RADUs) in R-5 Zones
As of May 2025, Clark County, Washington, has implemented several changes to permitting rules for Accessory Dwelling Units (ADUs), Rural Accessory Dwelling Units (RADUs), tiny homes, and guest homes in unincorporated areas zoned R-5. These changes aim to increase housing options while maintaining rural character. (ADU code changes approved, Section 40.260.022)
Under Section 40.260.022 of the Clark County Code, RADUs are permitted in the R-5 zone, provided the following conditions are met: (Section 40.260.022)
- One RADU per lot: Only one RADU is allowed per legal lot. Accessory to a single-family dwelling: The RADU must be subordinate to a primary single-family residence.
- Size limitations: The total floor area of the RADU shall not exceed 1,500 square feet.
- Development methods: RADUs can be created through internal conversions, additions to existing structures, garage conversions, or as part of new single-family construction.
- Compliance with codes: RADUs must adhere to applicable fire, health, and safety codes.
- Prohibited locations: RADUs cannot be located on properties where a Type II home business is operating. (Section 40.260.022)
Regulations were updated in 2024 to allow attached RADUs in rural areas, including the R-5 zone.
Tiny Homes and Guest Homes in R-5 Zones
Tiny homes are defined as detached single-family homes with a minimum of 150 square feet and built on a foundation. While the county has established definitions for tiny homes, specific permitting requirements for tiny homes in the R-5 zone are not detailed in the available sources. It’s advisable to consult the Clark County Unified Development Code or contact the Community Development Department for precise regulations.
Recent and Upcoming Code Changes
Clark County has amended its development code to encourage more diverse housing options:
- Accessory Dwelling Units (ADUs): The county adopted Ordinance 2024-03-02, which includes provisions such as allowing up to two ADUs per lot, removing the owner-occupancy requirement, and reducing impact fees by 75%. (ADUs and Cottage Housing | Clark County)
- Cottage Housing: The minimum size for cottage houses was reduced from 500 square feet to 150 square feet, and the maximum size was increased to 1,600 square feet.
- Tiny Homes: Tiny homes are now defined in the development code, allowing for their inclusion in housing strategies.
These changes align with the county’s Housing Options Study and Action Plan (HOSAP), which aims to provide a greater range of housing types in both urban and rural areas.