ADU Permitting in California
RESOURCES
Everything you need to know
What the ADU Permit Process Actually Involves
ADU Permitting
Every ADU in California requires building and zoning permits. The process typically involves: zoning review to confirm your lot qualifies, planning approval including site plan review and any environmental or historic district checks, building permits covering structural, electrical, mechanical, and plumbing, utility sign-offs for sewer, water, and electricity, construction inspections at key stages, and a Certificate of Occupancy once everything passes.
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Under California state law (AB 68), cities must approve complete ADU applications within 60 days. AmerADU manages the full permit lifecycle from design to occupancy, handling plan preparation, city submissions, and inspection coordination so you never have to chase paperwork.
Key Facts and Figures
ADUs in California: By the Numbers
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California issued permits for over 83,000 ADUs between 2016 and 2022 — a 15,000 percent increase
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As of 2022, nearly one in five new homes built in California is an ADU
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Average ADU rental income ranges from $1,500 to $3,500 per month depending on location and size
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ADUs typically add 20 to 35 percent to a property's appraised value
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California jurisdictions must approve complete ADU permit applications within 60 days under state law
What Permits Are Required?
REQUIREMENTS
A standard ADU project in California requires several permit types, though AmerADU manages all of them on your behalf. The zoning clearance confirms your property is eligible. The building permit covers structural, electrical, mechanical, and plumbing systems. For factory-built units like ours, the unit arrives with state factory certification, which simplifies the local building permit process significantly. Utility permits cover sewer, water, and electrical service. Finally, a final inspection results in the Certificate of Occupancy that makes your ADU legal for occupancy and rental.
How AmerADU Helps
Permits Handled
✔ Zoning review and eligibility confirmation
✔ Site plan preparation and submission
✔ Planning approval coordination
✔ Environmental and historic district clearance where required
✔ Certificate of Occupancy filing
AmerADU simplifies the entire ADU process from start to finish. Our factory-built, California-certified modular units are engineered to eliminate the delays and cost overruns that come with traditional on-site construction — you get a fixed timeline, fixed pricing, and a finished unit that meets CALGreen and WUI fire-resistant standards before it ever arrives on your property.
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Our permitting team manages your local jurisdiction on your behalf, handling everything from zoning review and plan preparation to city submissions, inspection coordination, and Certificate of Occupancy filing. You never have to chase paperwork or navigate a building department on your own.
PERMITTING & APPROVALS — WHAT TO EXPECT
Every ADU in California requires building and zoning permits, and every jurisdiction has its own requirements. AmerADU manages the full permit lifecycle on your behalf — zoning review, site plan preparation, city submissions, utility sign-offs, inspection coordination, and Certificate of Occupancy filing. Under California state law, jurisdictions must approve complete ADU applications within 60 days. We build every application to meet that standard the first time.
Common Questions About Permits
Frequently Asked
Under California state law (AB 68), all jurisdictions must approve a complete ADU permit application within 60 days. The key word is complete — an incomplete application resets the clock. AmerADU prepares thorough, code-compliant submissions tailored to your local jurisdiction, with a goal of first-time approval on every application we submit.
Every ADU in California requires a combination of permits: zoning clearance to confirm your lot qualifies, planning approval including site plan review and any environmental or historic district checks, building permits covering structural, electrical, mechanical, and plumbing work, utility sign-offs for sewer, water, and electricity connections, construction inspections at key stages, and a Certificate of Occupancy once everything passes. AmerADU manages all of it on your behalf.
For detached ADUs, separate utility meters are typically required by California jurisdictions, including separate connections for electricity, water, and sewer. Impact fees are generally waived for units under 750 square feet. AmerADU coordinates all utility sign-offs and connection requirements as part of our full-service permitting process.
Yes. Whether you are starting from scratch or already have a site and a unit in mind, AmerADU's permitting team steps in at whatever stage you need. We review your zoning eligibility, prepare all required documentation, submit to your local jurisdiction, coordinate inspections, and file for your Certificate of Occupancy. You do not need to manage any part of the permit process yourself.