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

Building lot coverage in unincorporated Ventura County is governed by Section 8106-1.4 of the Non-Coastal Zoning Ordinance. Building lot coverage is defined as the ratio of land covered by buildings (total building area) to gross lot area, expressed as a percentage. The maximum percentage depends on which of four categories the lot falls in: (1) lots subject to an area plan; (2) lots within a mapped existing community designated area and not subject to an area plan; (3) lots outside a mapped existing community and not subject to an area plan; and (4) lots meeting certain exceptions. For area-plan lots (e.g., El Rio/Del Norte, Lake Sherwood/Hidden Valley), Open Space and Agricultural designations are capped at 5%, Rural Residential at 25%, Urban Residential at 28% to 60% depending on density, Commercial and Institutional at 60%, and Industrial at 50% (Section 8106-1.4.1.1). For lots within a mapped existing community (such as Camarillo Heights, North Simi, Santa Rosa Valley), coverage ranges by zone: RA at 25%, RE at roughly 25-36%, R1 at 29-45%, R2 at 50%, and commercial/RPD at 60% (Section 8106-1.4.1.2, Table 8). For lots outside an existing community and not in an area plan, coverage follows the General Plan land use designation: Rural 25%, Agricultural and Open Space 5%, Mixed Use and Commercial 60%, and Industrial 50% (Section 8106-1.4.1.3, Table 9). Exceptions and exclusions, such as greenhouses and small nonconforming lots, are addressed in Section 8106-1.4.2.