Detached ADU
A separate backyard home with its own entrance.
City guide · San Bernardino County
ADUs in San Bernardino, California
The City of San Bernardino offers two ways to add an ADU: its Pre-Selected ADU Plans Program, or the traditional route of hiring an architect or designer for custom plans. Here is how San Bernardino homeowners can get started.
What is an ADU?
An Accessory Dwelling Unit is a smaller, independent home on the same lot as a primary residence. California law sets a statewide baseline for ADUs, and each city administers its own planning review, permits and inspections.
Types of ADUs to consider
Attached ADU
Built onto the existing home with independent exterior access.
Garage or space conversion
Turns existing space, such as a garage, into a living unit.
Junior ADU (JADU)
A smaller unit created within the walls of the existing home.
What the city says
- The pre-selected Standard Plans are designed and owned by the listed design firms and are purchased directly from the plan owner. The city notes they may not be approved for every site condition.
- Setbacks, zoning, height and lot coverage are set in the city's Development Code (Chapter 19.04, Residential Zones). The city's GIS map shows your property's zoning.
- The city notes it has high-wind, high-seismic and high fire-severity areas, which may affect construction costs and limitations.
Facts on this page come from the official sources listed. Requirements can change — confirm with the city before you design or build.
How the ADU process usually works
- Learn what your city allows and check your property's zoning and site conditions.
- Set a budget and choose a pre-approved plan or a custom design.
- Prepare plans and submit them to the city for planning and building review.
- Respond to plan-check comments, pay fees and receive your permit.
- Build with required city inspections, then receive final approval.
Official resources
- City of San Bernardino — Accessory Dwelling Units (Building & Safety)
- City of San Bernardino — Development Code
- City of San Bernardino — GIS Mapping (check your zoning)
Contact the city's Building & Safety Division through the official ADU page above.
Statewide guidance
Common questions
Should I use a pre-selected plan or a custom design?
Pre-selected plans are bought from the design firm that owns them and can simplify design, but the city notes they may not work for every site. A custom design can fit unusual lots. Compare both with the city before you buy plans.
How big can my ADU be, and what setbacks apply?
Size limits, setbacks, height and parking rules depend on your lot, zone and ADU type. ADU California does not publish these numbers unless we can source them directly. Confirm them with the City of San Bernardino Community Development & Housing Department before you design.
How much are permit fees and how long does approval take?
Fees and review times change and vary by project. Ask the City of San Bernardino Community Development & Housing Department for current fees and timelines. Our cost estimator gives a planning-level range, not a quote.
How ADU California can help
Use our free tools to understand your property and plan your budget. We are an independent homeowner resource, not a government agency — always confirm requirements with the city.
Information reviewed: 2026-10-08 · Other locations