Fraud alert: 600+ CA homeowners lost deposits to ADU scammers. Verify before you pay.
Find verified ADU builders in California
Every ADU scam in California starts the same way — a quietly expired license.
California’s verified ADU builders
CSLB-verified daily. Browse the full directory for search, filters, and detailed profiles.
ADU builders by city
Browse verified builders in California’s most active ADU markets
ADU types & average costs
California allows multiple ADU types on most single-family lots
Detached ADU
Garage Conversion
Prefab / Modular
Junior ADU (JADU)
California ADU contractors who took the money and ran
600+ homeowners lost tens of thousands. Here’s what happened.
Anchored Tiny Homes
Sacramento. Inc. 5000 #224. CEO claimed a $100M business. Chapter 7 bankruptcy: $12.8M in debts, $1.2M in assets. 450+ homeowners abandoned. CSLB license revoked.
Read the story →Multitaskr
Chula Vista. Took $15M+ from 100+ homeowners. Arranged loans under their names for ADUs that were never built. CSLB license revoked. Four officers banned. CEO filed bankruptcy.
Read the story →Nonna ADU
Sacramento. Named fastest-growing company in the region. One family paid $193K with zero work done. 23 CSLB complaints. License suspended. Accusation to revoke filed.
Read the story →ADU cost guide — California 2026
Average costs from Sacramento-area projects and permit data
| ADU Type | Typical Range |
|---|---|
| Detached ADU400-1,200 sq ft, new construction | $200K – $450K |
| Attached ADU400-800 sq ft, shares wall | $150K – $300K |
| Prefab / ModularFactory-built, installed on-site | $90K – $350K |
| Garage ConversionExisting structure, no new foundation | $70K – $150K |
| Junior ADU (JADU)Under 500 sq ft, within existing home | $40K – $100K |
750 sq ft detached ADU in Sacramento
Interactive calculator with Sacramento-specific pricing