ADU Permit Guide for San Bernardino, California — Step-by-Step Process (2026)

Before you submit any paperwork to San Bernardino's planning department, you must verify your property qualifies for ADU construction. Start with your property deed or title report to confirm you own the property outright — the city requires proof of ownership with your application. Your property must contain an existing legal single-family dwelling or duplex that received its certificate of occupancy before your ADU application.

Next, verify your zoning designation using the city's online zoning map /search. San Bernardino allows ADUs in residential zones RL (Residential Low Density), RM (Residential Medium Density), and RS (Residential Suburban). Print the zoning verification page — you'll need this for your permit application. The zoning designation appears on your property tax assessment, but the city's map provides the most current information.

Obtain a current title report from a title company (costs $200-$400) to identify any easements, liens, or deed restrictions that could block ADU construction. Some properties have CC&Rs (Covenants, Conditions & Restrictions) that prohibit accessory structures, though California law AB 68{:target="_blank"} limits HOA powers to restrict ADUs that comply with state requirements.

Your property cannot have certain disqualifying conditions. Properties in active code enforcement proceedings cannot receive ADU permits until violations are resolved. Properties with unpaid city fees, taxes, or utility bills face application holds. If your main house was built before 1978, you may need lead paint disclosures and asbestos testing reports before construction begins.

Finally, verify your property's legal address matches city records exactly. Address discrepancies delay permit processing by 2-4 weeks while staff research property records. Contact San Bernardino's Code Enforcement Division at (909) 384-5266 to confirm your property has no outstanding violations before investing in plans or applications.

Start your research at San Bernardino's Planning Division counter at 300 N D Street, or call (909) 384-5057 to schedule a pre-application meeting. These 30-minute meetings cost $150 but can save thousands by identifying deal-breaking issues early. Bring your property survey, zoning map printout, and a basic site sketch showing where you want to place the ADU.

San Bernardino follows standard California ADU setback requirements: 4 feet from side and rear property lines for structures under 16 feet tall. Front yard setbacks match your main house setback or 10 feet minimum. However, utility easements, septic systems, and mature trees can reduce buildable area significantly. Request a "setback worksheet" from planning staff to calculate your exact buildable envelope.

Check utility capacity before designing your ADU. Contact San Bernardino Municipal Water Department at (909) 384-5168 to verify water and sewer capacity for your additional unit. Properties on septic systems need percolation tests and health department approval, which adds 4-6 weeks to your timeline. Electrical service upgrades cost $2,000-$8,000 if your main panel cannot handle additional load.

The city's building department maintains files on every property. Request a "permit history report" ($25) to see previous additions, electrical upgrades, and any unpermitted work. Unpermitted structures must be brought to code or removed before ADU permits are issued.

Use San Bernardino's setback calculator /tools/setback-calculator to determine your maximum ADU size. California allows ADUs up to 1,200 square feet, but local setbacks, lot coverage limits (typically 40% in RL zones), and height restrictions (16 feet maximum) often reduce actual buildable size.

Document any protected trees on your property. San Bernardino requires permits for removing trees over 6 inches in diameter. Tree removal permits take 3-4 weeks and cost $200-$500 depending on species and size.

San Bernardino requires complete architectural plans for ADU permits — simple sketches will not suffice. Your plan set must include: site plan showing existing and proposed structures, floor plans with room dimensions and square footages, exterior elevations from all four sides, foundation plan with structural details, electrical plan showing outlets and fixtures, and plumbing plan showing water and sewer connections.

Hire a California-licensed architect (typical cost: $8,000-$15,000) or use pre-approved ADU plans if available through the city. San Bernardino has not yet adopted a pre-approved plan program, so custom design is currently required. Your architect must include Title 24{:target="_blank"} energy compliance calculations showing insulation values, window efficiency ratings, and HVAC specifications.

The structural plan requires engineered drawings if your ADU exceeds 600 square feet or includes complex features like large windows or unusual roof designs. Structural engineering costs $2,500-$5,000 additional. Soil reports are required for ADUs over 1,000 square feet or on sloped lots exceeding 10% grade.

Show precise dimensions on all plans. Room sizes must meet California building code{:target="_blank"} minimums: 120 square feet for bedrooms, 50 square feet for bathrooms, 150 square feet for living areas. Ceiling heights must be 7'6" minimum in bedrooms and living areas, 7' minimum in bathrooms and kitchens.

Include utility connection details showing how water, sewer, gas, and electrical services connect to existing systems. The city requires separate utility meters for ADUs over 750 square feet unless you choose not to rent the unit separately.

Your architect must seal and sign all plan sheets. Missing signatures or expired licenses cause automatic rejections. Verify your architect's California license is current at www.cab.ca.gov before hiring.

Submit plans printed on 24" x 36" paper — the city does not accept smaller formats for ADU applications. Include a digital PDF copy on USB drive with your application package.

Submit your ADU permit application at San Bernardino's Development Services counter, 300 N D Street, 3rd floor. The counter is open Monday-Thursday 7:00 AM to 5:30 PM, Friday 8:00 AM to 5:00 PM. Currently, San Bernardino does not offer online ADU permit submissions.

Your application package must include: completed ADU Permit Application form (Form DS-101), complete plan set (4 copies), property survey or plot plan, title report or deed, zoning verification printout, structural calculations (if required), soil report (if required), and tree survey (if trees present).

Application fees total $5,000-$15,000 depending on ADU size and complexity. The base plan check fee is $2,200 for ADUs under 750 square feet, $3,400 for larger units. Building permit fees calculate at $8.50 per $1,000 of construction valuation. School impact fees apply at $4.79 per square foot — this cannot be waived.

Pay additional fees for: electrical permit ($250-$450), plumbing permit ($180-$320), mechanical permit for HVAC ($150-$280), and fire department review ($125). Plan check fees are due at application submission. Building permit fees are due at permit issuance.

Complete the application form accurately. Common errors include: incorrect parcel number (found on property tax bill), wrong construction valuation (use $250-$400 per square foot), missing owner signature with notarization, and incorrect existing square footage measurements.

Staff perform a completeness check within 3-5 business days. Incomplete applications receive rejection letters listing missing items. Complete applications enter the formal review queue with assigned case numbers. Keep your receipt and case number for all future correspondence.

The city has 60 days from accepting a complete application to approve or deny ADU permits under California law. This timeline starts only after your application passes the completeness review.

After submission, your ADU permit moves through four review stages: planning review (zoning compliance), building review (structural and code compliance), fire department review (access and safety), and public works review (utility connections and drainage).

Planning review typically takes 2-3 weeks. Staff verify setback compliance, lot coverage calculations, and height restrictions. They also confirm your ADU design meets state requirements for independent living (separate kitchen, bathroom, and sleeping area).

Building plan review takes 3-4 weeks and generates the most correction comments. Building reviewers check structural adequacy, foundation design, electrical load calculations, plumbing fixture counts, ventilation requirements, and Title 24{:target="_blank"} energy compliance. Expect 15-25 correction items on first review for typical ADU projects.

Fire department review focuses on emergency access and fire separation between structures. ADUs within 10 feet of main houses require one-hour fire-rated exterior walls. Properties with narrow driveways may need fire sprinkler systems, adding $4,000-$8,000 to construction costs.

Public works review examines utility connections and stormwater management. New sewer connections require capacity studies and may trigger upgrade requirements. Properties in flood zones need additional drainage calculations.

Correction letters arrive by mail 5-7 business days after review completion. Each correction includes specific code references and required fixes. Address every correction item — partial responses delay processing.

Resubmit corrected plans with response letters explaining each change. Highlight corrections in red ink on plan sheets. Second reviews take 2-3 weeks. Most ADU permits require 2-3 correction cycles before approval.

Track your application status by calling the assigned plan reviewer directly. Phone numbers appear on correction letters and review status updates.

Once San Bernardino issues your ADU building permit, you have 180 days to begin construction. Request permit extensions (costing $200) before expiration if construction delays occur. Posted permits must remain visible at the job site throughout construction.

Schedule inspections by calling (909) 384-5235 or using the city's automated inspection request line. Request inspections at least 24 hours in advance. Morning inspection slots (7:00-11:00 AM) fill quickly — call before 3:00 PM the previous business day.

Required inspections occur in sequence: foundation inspection (before concrete pour), framing inspection (after rough framing completion), rough electrical inspection (before insulation), rough plumbing inspection (before covering pipes), rough mechanical inspection (HVAC installation), insulation inspection (before drywall), and final inspection (project completion).

Foundation inspections verify proper excavation depth, rebar placement, and anchor bolt locations. Inspectors check that foundation dimensions match approved plans exactly. Failed foundation inspections require concrete removal and rework, costing $3,000-$8,000.

Framing inspections examine structural member sizes, connection hardware, and earthquake bracing. Inspectors verify ceiling heights, room dimensions, and window/door openings match plans. Have your structural engineer present for complex framing inspections.

Rough utility inspections check installation before covering with insulation and drywall. Electrical inspectors verify proper wire sizes, outlet locations, and panel connections. Plumbing inspectors test water pressure and check fixture connections. Schedule all rough inspections together when possible.

Final inspection covers everything: completed finishes, working fixtures, proper ventilation, smoke detector placement, and code compliance verification. Prepare a punch list of minor items before calling for final inspection.

Inspection failures require correction and re-inspection fees ($75-$125 per trade). Keep your contractor available to address inspection comments immediately.

After passing final inspection, request your Certificate of Occupancy (CO) from San Bernardino's Building Division. The CO application costs $150 and requires a final walk-through inspection focusing on life safety systems: smoke detectors, carbon monoxide detectors, exit door operation, and address numbering.

The city assigns a separate address to your ADU for mail delivery and emergency response. Address assignment takes 1-2 weeks and costs $85. Your ADU address typically adds a unit designation (like 123 Main Street Unit B) or uses a fraction system (like 123½ Main Street).

Schedule utility connections after receiving your CO. Contact San Bernardino Municipal Water Department to activate water and sewer service ($200 connection fee). Arrange electrical service activation through Southern California Edison — this requires your electrical permit final approval and CO documentation.

You cannot legally rent your ADU until receiving the Certificate of Occupancy. Renting without a CO violates city codes and creates liability issues with insurance companies. Some mortgage lenders require CO copies before releasing construction loan funds.

Record your new ADU with San Bernardino County Assessor's Office to establish separate property tax assessment. This typically increases property taxes by $2,000-$6,000 annually but also increases property value by $150,000-$300,000 for completed ADUs.

The entire permit and construction process typically takes 6-14 months: 2-3 months for design and permit approval, 4-6 months for construction, and 2-4 weeks for final approvals and CO issuance. Weather delays, inspection failures, and plan revisions can extend this timeline.

Keep all permit documents, inspection records, and CO certificates permanently. Future property sales require this documentation to verify legal ADU status.

Setback violations cause 35% of ADU permit denials in San Bernardino. Many property owners miscalculate distances from property lines, especially on irregularly shaped lots. Use a licensed surveyor ($800-$1,200) to verify exact property boundaries before designing your ADU. The city building codes /tools/codes/san-bernardino provide specific setback requirements, but corner lots and through-lots have additional restrictions.

Incomplete or inaccurate plans trigger automatic rejections. Missing structural calculations, unsigned plan sheets, incorrect square footage calculations, and omitted utility connection details account for 40% of first-review rejections. Have your architect review the city's plan submission checklist before submitting applications.

Utility capacity problems delay permits by 6-12 weeks. Properties with inadequate water pressure, overloaded electrical panels, or failing septic systems cannot support ADUs without expensive upgrades. Sewer line replacements cost $8,000-$15,000. Electrical service upgrades range from $3,000-$12,000 depending on distance from utility transformers.

HOA restrictions still affect some ADU projects despite state law changes. CC&Rs recorded before 2020 may contain enforceable ADU prohibitions. Review your HOA documents carefully and consult a real estate attorney if conflicts exist. Legal challenges add 6-18 months to project timelines.

Fire department access requirements surprise many ADU applicants. Properties with driveways narrower than 20 feet or ADUs located more than 150 feet from fire truck access may require expensive sprinkler systems. Fire access roads must support 75,000-pound fire trucks — many residential driveways need structural improvements costing $5,000-$20,000.

Tree preservation ordinances protect significant trees throughout San Bernardino. Removing protected trees without permits results in fines up to $1,000 per inch of tree diameter. Oak trees larger than 8 inches require special permits and sometimes replacement tree plantings. Plan ADU locations to avoid tree conflicts rather than assume removal approval.

Historical district restrictions apply in older San Bernardino neighborhoods. Properties in historical overlay zones face additional design review requirements and architectural restrictions. Historical review adds 4-8 weeks to permit processing and may require design modifications to match neighborhood character. Contact the city's Planning Division to verify if historical restrictions apply to your property.