Is Permit work required for an ADU?
Yes—permit work is required for an ADU in almost all cases. If you’re asking “do you need a permit for an ADU?” or “do you need a permit to build an ADU?” the answer is yes. An accessory dwelling unit is considered a livable structure, which means it must comply with building, safety, and zoning standards set by your local jurisdiction.
Understanding ADU permit requirements early helps avoid delays, unexpected costs, and legal issues down the line.
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Why an ADU Permit Is Required
An ADU building permit is required because ADUs involve regulated construction that affects health and safety. These permits ensure compliance with:
Structural and seismic requirements
Electrical systems and panel capacity
Plumbing and sewer connections
Mechanical and ventilation systems
Fire safety and egress
Energy efficiency standards
Zoning and setback rules
Because an ADU is a dwelling unit—not just a storage space—it must meet all ADU legal requirements before it can be occupied or rented.
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Types of ADU Permits You May Need
A complete ADU construction permit package often includes several approvals, depending on the scope of work:
Building permit (primary permit)
Electrical permit
Plumbing permit
Mechanical permit
Grading or drainage permit (if site work is involved)
Encroachment permit (if public right-of-way is affected)
Demolition permit (for existing structure removal)
Some cities issue these as a combined permit, while others separate them into individual approvals.
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How ADU Regulations Affect the Permit Process
ADU regulations and review requirements vary depending on the type of ADU you’re building:
Detached ADU
Typically requires the most review and documentation
Attached ADU
Often includes structural tie-ins and fire separation details
Garage or Interior Conversion ADU
Still requires a permit, even though the structure already exists
Junior ADU (JADU)
May have a simpler review process, but permits are still required
No matter the type, ADU approval is mandatory before construction begins.
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ADU Permit Requirements by City
While California has statewide ADU laws, ADU permit requirements by city can still differ. Most jurisdictions require:
Site plan showing property lines and setbacks
Floor plans and exterior elevations
Structural calculations (when required)
Energy compliance documentation (Title 24)
Fire and life-safety notes
Utility connection details
Having accurate plans and a clear scope improves review times and reduces resubmittals.
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Are There Any Situations Where an ADU Permit Isn’t Required?
Minor cosmetic work may not require permits, but once you add kitchens, bathrooms, utilities, or change the use of a space, a permit is required. Creating a new dwelling unit always triggers accessory dwelling unit permit requirements.
So if you’re wondering again:
Do you need a permit for an ADU?
Yes—almost always.
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Ready to Plan Your ADU Project?
Whether you’re considering a garage conversion or a ground-up ADU build, the next step is a site visit and a clear plan tailored to your property.
If you’re looking for experienced professionals to manage ADU permits, navigate local ADU regulations, and guide your project from concept through construction, EDR Design Build offers a streamlined design-build process focused on clarity, compliance, and quality craftsmanship.
Call: (650) 888-2107
Email: [email protected]
Serving San Jose, Campbell, Los Gatos, Saratoga, Cupertino, Sunnyvale, Santa Clara, Mountain View, Los Altos, Los Altos Hills, Palo Alto, Menlo Park, Stanford, Woodside, Emerald Hills, Atherton, South San Francisco, Redwood City, Foster City, Portola Valley, Belmont, San Mateo, Burlingame, Millbrae, Hillsborough, San Bruno, Daly City, Colma, Brisbane, Pacifica, Milpitas, San Carlos, and Bay Area communities.
