Within each zoning district the municipal code defines four types of uses - principal, accessory, conditional and prohibited.
- Principal uses relate to the main purpose of the district, exist independently of any other use of a property, and are allowed "by right." Dwellings in a residential district or stores in a business district are examples of principal uses.
- Accessory uses are always associated with principal uses, like a garage is always associated with a house. There can be no accessory use on a property without a principal use.
- Conditional uses are activities that may create significant traffic, noise, or other impacts on the surrounding neighborhood. The Planning and Zoning Commission may allow these uses, but also may place restrictions on them to protect the surrounding properties. Conditional use cases involve a public hearing, with notices posted on the property, published in a local newspaper, and mailed to surrounding property owners. Conditional uses have standards for approval specified in section 21.50 of the municipal code. The Zoning and Platting Division has published a Self Help section that provides detailed information on applying for a Conditional Use Permit.
- Prohibited uses are those activities that the Assembly has found to be incompatible with the zoning district.
There is a provision in the code (AMC 21.40.015.B) that harmonizes the permitted and prohibited classifications. If a use is allowed as a principal, accessory or conditional use in any zoning district, it is prohibited in all districts where it is not listed. For example: junkyards are a conditional use in the I-2 Heavy Industrial district, so they are not allowed in the R-1 Single Family Residential district even though they are not specifically listed as a prohibited use.
If you have any questions about whether a particular use is permitted in a district, you can look it up in the zoning district regulations. If you are still unsure, you can call Land Use Enforcement for an informal, verbal code interpretation. There is also a formal process called a use determination.
Uses that were legally established before zoning was enacted, and have existed continuously since that time, may have nonconforming (grandfather) rights.