San Bernardino ADU Requirements and Permit Starting Point
Research San Bernardino ADU rules for detached units, attached ADUs, garage conversions, and JADUs. Begin with jurisdiction, zoning, objective standards, utilities, fire access, documents, and official department confirmation.
City and county
San Bernardino is in San Bernardino County. Confirm the parcel is inside city limits before relying on city ADU standards; parcels outside city limits may start with the county instead.
Official links
Local notes
- San Bernardino ADU review should include utility capacity, fire access, lot standards, existing structures, and plan-check requirements.
- Confirm the zoning district, overlays, setbacks, height, lot coverage, parking, easements, fire access, and whether the property is inside city limits before relying on city rules.
- Confirm sewer and water service, electric capacity, fire flow, driveway access, drainage, and any service upgrades before estimating the project.
- Expect zoning intake, site plan review, building plan check, corrections, fees, final review, and inspections. Some projects need public works, fire, environmental health, or utility clearance.
- Ask whether detached ADU, attached ADU, garage conversion, and JADU submittals use different checklists or review steps.
- Confirm whether fire access, utility capacity, public works, historic, coastal, hillside, or HOA issues could affect the site.
- Save official links, staff names, dates, and written notes before relying on a design budget.
Separate the city from unincorporated San Bernardino County
The City of San Bernardino and unincorporated San Bernardino County use different planning and building departments. Confirm jurisdiction from the APN before using a city or county ADU handout. If the parcel is outside city limits, begin with County Land Use Services and the county-specific guide. Inside the city, use the official city links on this page. This distinction affects zoning lookup, submittal instructions, permit contacts, utility coordination, and local development standards even though both locations share the San Bernardino name.
Site and utility conditions to verify
Before selecting an ADU plan, document the existing home, proposed location, setbacks, access, slope, drainage, utilities, sewer or septic, fire conditions, and recorded easements. Ask which agency provides water and sewer service and whether the project requires capacity review, a new connection, trenching, or panel work. In foothill or edge conditions, confirm fire access and hazard requirements early. A preapproved or standard plan can reduce some design work but does not approve the parcel, foundation, grading, utility route, or site-specific permit documents.
Build a complete permit file
Collect the APN, zoning result, existing permit history, site plan, photographs, utility notes, title and HOA documents where relevant, and the current ADU application checklist. Ask whether detached, attached, conversion, and JADU projects use different submittal requirements. Confirm who reviews planning, building, fire, public works, utilities, and environmental health. When comparing builders, require each proposal to state responsibility for design, engineering, permit corrections, agency fees, utility work, sitework, inspections, and final records rather than relying on a single turnkey label.
ADU types to compare
- Detached ADU
- Attached ADU
- Garage conversion ADU
- Junior ADU
What to verify
- Setbacks
- Height
- Size
- Lot coverage
- Parking
- Owner occupancy if applicable
- Fire access
- Utilities
- Impact, connection, or school fees
- Historic, coastal, hillside, fire, flood, or HOA overlays
Questions to ask planning
- Is this parcel inside city limits?
- Which ADU standards apply to this project type?
- What zoning, overlays, setbacks, height, size, and lot coverage standards should be used?
- Are coastal, historic, hillside, fire, flood, HOA, or specific plan issues relevant?
Questions to ask building
- What plan sheets and energy documents are expected?
- How are garage conversions reviewed for existing conditions?
- What inspections and correction cycles should be expected?
- Do utilities, fire separation, egress, or structural upgrades need early review?
Documents to collect
- APN and assessor record
- Zoning lookup screenshot
- Existing site plan or parcel sketch
- Photos of access and existing structures
- Prior permits if available
- Utility provider notes
- HOA or title documents if relevant
Related guides
Need help reviewing a San Bernardino ADU property?
Share the property and project details so the next ADU research steps are easier to organize before calling local departments.
Frequently Asked Questions
Can I rely on this San Bernardino ADU summary by itself?
No. Use it to organize questions, then confirm the current standards directly with local planning, building, fire, utility, and public works staff.
Which department should I contact first?
Start with planning to confirm jurisdiction, parcel zoning, ADU type, and objective standards. Then confirm building, utilities, fire access, and public works requirements.
Do garage conversions and detached ADUs use the same review path?
Not always. They may share an ADU framework but differ in existing-condition review, fire separation, utilities, parking assumptions, and plan documents.
TinyHomeNavigator provides educational information only. Rules vary by parcel, zoning district, city, county, overlay, utility provider, fire authority, and environmental health department. Always confirm directly with the local planning department, building department, environmental health department, fire authority, and utility providers before buying land, designing, permitting, placing, or building any structure.