Simi ValleySimi Valley is the third largest of Ventura County's ten cities with an estimated population of 126,380. Approximately 42 square miles in area, the City is in Southeast Ventura County, adjacent to the San Fernando Valley and 37 miles northwest of downtown Los Angeles.
Simi Valley ADU Permits and Regulations Resources
Max ADU Size
Lot under 9,000 sqft: 600 sqft Lot between 9,000 and 1000 sqft: 650 sqft Lot over 10,000 sqft: 800 sqft
45’ Note: Front setbacks vary by zoning, please talk to a home specialist to confirm
Primary Residence Setback
Side and Rear Setback