Honest 2026 pricing for Inland Empire 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
$350–$475/sqft
Garage / interior conversion
$210–$315/sqft
Why Inland Empire prices look like this
☐Lowest cost in our service area — flat lots, big parcels, lower labor rates.
☐VHFHSZ Chapter 7A on foothill parcels adds $18–35k.
☐SCE service drop is the most common cost surprise — $4–18k depending on distance.
☐Big parcels mean detached ADUs over 1,000 sqft are common, scaling cost linearly.
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.