County offers tools to help homeowners add accessory dwelling units

"San Bernardino County Update", yellow arrowhead and "SBCounty.gov

A small gray house with a porch and two lawn chairs. Text “Accessory Dwelling Units (ADUs)” with the San Bernardino County Land Use Services logo.

Accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs) are small, independent living spaces built on residential properties. Often known as casitas, backyard cottages or in‑law suites, they offer flexible housing options for families, renters and homeowners looking to add space or generate extra income.

As ADUs gain popularity statewide, the county has taken meaningful steps to make the process easier for residents. The San Bernardino County Land Use Services Department plays a central role in helping homeowners understand what is allowed, how to get started and how to move through the permitting process.

What San Bernardino County offers

San Bernardino County allows most single‑family residential properties to add an ADU, and depending on lot size, homeowners may also be able to include a JADU or guest house. Since sewer or septic capacity can affect what is possible, the county encourages early coordination with Environmental Health Services.

To simplify the building process, the county provides four pre-approved detached ADU plans. These plans have already been reviewed for code compliance, which can:

Reduce design costs
Speed up permit review
Trigger state‑mandated streamlining that may shorten approval times by up to 30 days

Land Use Services also offers an informational guide in English and Spanish that outlines permitting steps, timelines, fees and development standards, providing homeowners with a clear roadmap from planning to construction.

Additional County Update News – June 11, 2026