Zoning: A system of land use regulations that divides a municipality into districts (zones) and specifies the types of uses, building sizes, heights, setbacks, and densities permitted in each zone.
How Zoning Works
Zoning ordinances divide a city or county into districts — residential, commercial, industrial, mixed-use, and many subcategories of each. Each district has a set of rules governing what can be built: permitted uses, maximum building height, minimum lot size, setbacks from property lines, floor-area ratios, and parking requirements. Before any building permit can be issued, the proposed project must comply with the zoning rules for that district.
Common Residential Zoning Districts
Single-family residential zones (often called R-1) typically permit one detached single-family home per lot with specific setback and height limits. Multi-family zones (R-2, R-3, etc.) permit duplexes, triplexes, or apartment buildings. Mixed-use zones allow residential and commercial uses on the same property. The specific rules vary enormously by city.
Zoning vs. Building Codes
Zoning and building codes are separate regulatory systems. Zoning controls what can be built where — land use, density, setbacks. Building codes control how something must be built — structural standards, fire safety, electrical, plumbing. A project must comply with both. Zoning approval generally comes before the building permit application.
When Zoning Is an Issue
Zoning becomes an active issue when you want to do something your zoning district doesn't allow. Adding an ADU in a single-family zone, running a business from a residential property, or building taller than the height limit all require either rezoning or a variance. Check your zoning district before designing a project — discovering a zoning conflict after plans are drawn is expensive.