Thousand Oaks, CA Accessory Structures: ADU Impact Fees (2026)

Under Gov. Code §65852.2(f)(1) — implemented locally through TOMC Title 9 — Thousand Oaks cannot impose any impact fee (traffic, parks, school, drainage, etc.) on an ADU of less than 750 square feet. For ADUs 750 sq ft and larger, impact fees must be charged proportionally to the square footage of the primary dwelling unit; the per-square-foot ADU fee cannot exceed what would apply to the primary unit. Water and sewer connection charges are likewise limited: Gov. Code §65852.2(f)(3) bars the City and connection-fee agencies from requiring a new or separate utility connection for an ADU created within an existing single-family dwelling. In Thousand Oaks, water service is delivered through the City Public Works/Water Division (Cal Water also serves parts of the area), and sewer is via the City's Hill Canyon Treatment Plant collection system. School impact fees from Conejo Valley Unified School District (Education Code §17620 / Gov. Code §65995) apply at the state-mandated proportional rate for ADUs 500+ sq ft. Total fees vary by parcel and connection method — request a current fee estimate from Community Development before submitting plans.