Antioch, CA Building Setbacks & Zoning: Lot Coverage Limits (2026)

601 adopts the city's basic height, area, and setback chart, instructing readers to find the applicable zoning district on the left and read across to the Maximum Lot Coverage column. The table sets that ceiling as a percentage of lot area a building's footprint may occupy: the R-4, R-6, and R-10 single-family and low-density zones are held to 40%; the higher-density R-25 and R-35 districts, along with the M-1 and M-2 industrial districts, allow up to 50%; and the C-0 (Professional Office), C-1 (Convenience Commercial), and C-2 zones are held to 35%.

The RTC (Regional Transit Corridor) district is the outlier, listing 100% coverage consistent with its intended urban, transit-oriented building-to-property-line form. Coverage is measured against the minimum building site size specified in the same table row (for example, 6,000 square feet in R-6), so a 6,000-square-foot R-6 lot may build up to 2,400 square feet of footprint before triggering additional review. The table's percentages are the binding numeric standard for each zone; any project intending to exceed the listed coverage for its zone needs Planning Commission review as a modification under the city's design-review procedures rather than a routine building permit, and the modification cannot be used to bypass parking or other development standards.