ADU Rules in San Bernardino, California

Complete guide to building an Accessory Dwelling Unit in San Bernardino — zoning, setbacks, permits, costs, and more.

Max Size: 1200 sq ft; reduces to 800 sq ft if lot coverage exceeded Setbacks: 4 ft minimum (detached new construction) No Parking Required Verified: 2026-06-28
ADU Score: 8/10
Very ADU-friendly · how we score

The City of San Bernardino allows ADUs in most residential zones with no parking requirements and a state-mandated 60-day approval timeline. Favorable, state-aligned zoning with low local restrictions. (Unincorporated areas are governed separately by San Bernardino County Land Use Services.)

Outside city limits? If your property is in unincorporated San Bernardino County (not within San Bernardino's boundaries), different rules apply — see our San Bernardino County (unincorporated) ADU rules.

Zoning & Size Requirements [1][2]

Yes, you can build an ADU in San Bernardino. A detached ADU can be up to 1,200 sq ft under current California and San Bernardino zoning rules.

Allowed ZonesMost residential zones (R-1, R-2, R-3, multifamily)
Max Size (Detached)1200 sq ft; reduces to 800 sq ft if lot coverage exceeded
Max Size (Attached)1200 sq ft or 50% of primary dwelling, whichever is less
Max Size (JADU)500 sq ft
Max Height16 ft minimum; up to 25 ft with exceptions
Max Units1 ADU + 1 JADU per single-family lot; multifamily lots may add up to 8 detached ADUs (SB 1211), not exceeding the number of existing units, plus conversions of non-habitable space

Setback Requirements [1][2]

San Bernardino requires a rear setback of about 4 ft for a detached ADU, and no additional parking is required. Owner-occupancy is not required — you can rent it out without living on the property.

Rear Setback4 ft minimum (detached new construction)
Side Setback4 ft minimum (interior side, detached new construction)
Front SetbackBase zone compliance
Parking RequiredNo additional parking required (conversions/existing exempt)
Owner OccupancyNot required under state law
Min Lot SizeNo specific state minimum

Permit Process & Fees [3]

An ADU permit in San Bernardino typically costs $3,000-$12,000 estimated (building permit + plan check; varies by size) and takes 60 days mandatory for approval/denial of complete applications with an existing dwelling, through a ministerial, by-right review.

Approval ProcessSubmit to the City of San Bernardino Community & Economic Development (Planning/Building). Ministerial review for compliant ADUs. (Properties in unincorporated areas go to San Bernardino County Land Use Services instead.)
Review Timeline60 days mandatory for approval/denial of complete applications with an existing dwelling
Permit Fees$3,000-$12,000 estimated (building permit + plan check; varies by size)
Impact FeesWaived under 750 sq ft (SB 13); proportional for larger units
Plan CheckIncluded in the permit timeline; agency must respond within 60 days
Pre-Approved PlansStandard/pre-approved ADU plan options available (confirm City vs. County program for your address)

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Construction Costs

Building an ADU in San Bernardino typically costs $160,000-$280,000 ($200-$260 per sq ft); a garage conversion runs $75,000-$140,000.

Average Build Cost$160,000-$280,000
Cost per Sq Ft$200-$260
Garage Conversion$75,000-$140,000
Prefab ADU (Installed)$80,000-$150,000

Finance Your ADU Project

Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.

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Rental Income Potential

A 2-bedroom ADU in San Bernardino rents for around $1,700-$2,100, an estimated 7-10 year payback.

Avg Rent (1 Bedroom)$1,300-$1,700
Avg Rent (2 Bedroom)$1,700-$2,100
Short-Term RentalSubject to city/county ordinances; verify before planning
Est. Annual ROI7-10 year payback

Explore Prefab ADU Options

Prefab ADUs can save 20-40% vs. traditional construction and cut build time in half.

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Recent Law Changes

What's Changed Recently

  • Data accuracy correction (2026-06-28): updated per official city/state sources following a regulatory audit.
  • SB 543 (Jan 2026): ADU applications deemed approved if city fails to act within 60 days
  • AB 1154 (effective Jan 1, 2026): A locality may require owner-occupancy for a JADU only if it shares a bathroom with the primary dwelling; JADUs with their own bathroom are exempt (matching detached ADU rules)
  • SB 13 impact fee waivers for <750 sq ft units
  • County mandates 60-day approval timeline

Tips for Building an ADU in San Bernardino

  • Confirm whether your address is in the City of San Bernardino or unincorporated County — they use different permit offices
  • 60-day approval timeline is legally mandated for complete applications
  • Check if your property qualifies for a CalHFA ADU grant (when funding rounds are open)
  • No parking requirements reduce construction costs
  • Contact City of San Bernardino Community & Economic Development for City parcels

ADU Builders in San Bernardino

Looking for an ADU builder in San Bernardino? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match San Bernardino homeowners with experienced local ADU contractors who provide free, no-obligation quotes. Getting at least three bids typically saves 20-40% on the same scope.

Sources & References

All data on this page is sourced from official government records and verified market data. View our full methodology.

  1. City of San Bernardino — Community & Economic Development (Planning) Planning Department — Accessed 2026-06-28
  2. San Bernardino County Land Use Services — ADU/JADU Handout (unincorporated areas) Government Data — Accessed 2026-06-28
  3. City of San Bernardino — Building & Safety / Permits building_dept — Accessed 2026-06-28
  4. California HCD — Accessory Dwelling Unit Handbook (updated March 2026) Government Data — Accessed 2026-06-28
  5. CA SB 543 (2025-2026) — Accessory dwelling units and junior accessory dwelling units (full bill text) Government Data — Accessed 2026-06-28

Frequently Asked Questions

Can I build an ADU in San Bernardino?

Yes. ADUs are allowed in Most residential zones (R-1, R-2, R-3, multifamily) in San Bernardino. The maximum size for a detached ADU is 1200 sq ft; reduces to 800 sq ft if lot coverage exceeded. Owner-occupancy is not required, so you can rent out the ADU.

How much does an ADU cost in San Bernardino?

ADU construction in San Bernardino typically costs $160,000-$280,000. Garage conversions run $75,000-$140,000, and prefab ADUs cost $80,000-$150,000.

How much can I rent an ADU for in San Bernardino?

Average ADU rents in San Bernardino are $1,300-$1,700 for a 1-bedroom and $1,700-$2,100 for a 2-bedroom unit.

Do I need parking for an ADU in San Bernardino?

No additional parking required (conversions/existing exempt). Check with San Bernardino planning department for the latest California ADU parking rules, as many states have relaxed requirements in recent years.

How long does it take to get an ADU permit in San Bernardino?

The permit review timeline in San Bernardino is 60 days mandatory for approval/denial of complete applications with an existing dwelling. Fees range from $3,000-$12,000 estimated (building permit + plan check; varies by size).

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