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

Rather than a single county-wide lot-coverage percentage, Sierra County's zoning districts each set the standard that limits how much of a parcel can be built upon. The clearest example is the R1 residential one-family district (SCC 15.12.080), whose 'Minimum Area, Width and Open Space' standard requires that sixty percent of the lot or parcel shall be open and clear of structures, which functions as a roughly 40 percent maximum building coverage. R1 also sets minimum lot areas tied to water and sewer service: 8,000 square feet when connected to an approved public water and public sewer system, 10,000 square feet with public water and an individual sewage disposal system, and one acre when using a private well and individual sewage disposal, along with a minimum 60-foot parcel width. In the rural residential districts, coverage is controlled chiefly through large minimum parcel sizes and setbacks, for example one acre minimum in RR-1 (SCC 15.12.190) and 2.5 acres in RR 2.5 (SCC 15.12.205), which spread development out across larger lots. Commercial districts such as CC (SCC 15.12.130) set their own minimum lot sizes (for example 5,000 square feet with public water and sewer). Because the controlling standard differs by zone, owners should confirm the open-space and lot-area requirements for their specific parcel with the Sierra County Planning Department in Downieville.