Building Permit

Government authorisation to begin construction. Issued by the city's building department after plan check confirms code compliance.

Why it matters

Every ADU in California requires a building permit. State law mandates 60-day ministerial review from a complete application. Realistic full timeline (design + plan check + permit + construction): 12-18 months. Permit fees: $5k-$25k typical.

Related terms

• Plan Check
• Ministerial Review
• Impact Fees

See also

• Permit timeline guide

Part of the BackyardADU California ADU Glossary — plain-English definitions of the regulatory, construction, and financing terms you'll encounter during a California ADU project.