Honest 2026 pricing for Ventura County ADU projects. These ranges are installed cost — design, permit, construction, and standard finishes — based on jobs we've actually closed in this market.
Installed cost ranges
Detached new-build
$385–$510/sqft
Garage / interior conversion
$225–$335/sqft
Why Ventura County prices look like this
☐Lower labor cost than LA city — typically 8–12% below LADBS-area equivalents.
☐VHFHSZ Chapter 7A on Conejo Valley / Ventura backcountry parcels adds $18–35k.
☐Coastal Zone CDP on Ventura / Oxnard waterfront adds $15–35k in soft costs.
☐HOA architectural review (Thousand Oaks) is fee-light but schedule-heavy.
How to read these numbers
These are total installed $/sqft, not just construction. The detached range assumes a clean 600–900 sqft new-build with mid-range finishes. Conversions price lower because the shell already exists — most cost lives in plumbing, electrical, and the kitchen. Move outside these ranges and we'll tell you why before you sign anything.