San Jose ADU rules

Detached ADUs are authorized on the same lot as a proposed or existing primary dwelling.

Attached ADUs are authorized.

Existing dwelling space and accessory structures, including garages, may be converted to ADUs.

JADUs are authorized on qualifying single-family residential lots with a proposed or existing single-family residence.

• Note: Conditions apply

A lot with a proposed multifamily dwelling may have up to two detached ADUs.

• Note: Conditions apply

One JADU is allowed per qualifying single-family residential lot.

• Note: Conditions apply

ADUs are authorized on lots with a proposed or existing primary residence in qualifying residential or mixed-use areas.

• Note: Conditions apply

An ADU is a residential use consistent with the lot's existing general-plan and zoning designations where the lot allows single-family or multifamily residential use.

A primary dwelling may be proposed rather than already built.

• Note: Conditions apply

A detached ADU may not exceed 1,200 square feet under the statewide baseline.

• Note: Conditions apply

Local size and related development standards must allow at least an 800-square-foot ADU with four-foot side and rear setbacks.

An attached ADU on a lot with an existing primary dwelling may not exceed half of the primary dwelling's floor area.

• Note: Conditions apply

A local maximum size rule may not be lower than 1,000 square feet for an ADU with more than one bedroom.

• Note: Conditions apply

An attached ADU must be allowed up to 25 feet or the primary dwelling's applicable zoning height, whichever is lower; it need not exceed two stories.

• Note: Conditions apply

A detached ADU receives two additional feet where needed for a roof pitch aligned with the primary dwelling.

• Note: Conditions apply

A detached ADU within one-half mile walking distance of qualifying transit must be allowed to reach 18 feet, plus applicable roof-pitch height.

• Note: Conditions apply

A detached ADU on a lot with an existing or proposed multistory multifamily dwelling must be allowed to reach 18 feet.

• Note: Conditions apply

A local side setback may be no more than four feet for a new ADU not converted from an existing structure.

• Note: Conditions apply

A local rear setback may be no more than four feet for a new ADU not converted from an existing structure.

• Note: Conditions apply

No setback is required for an existing structure converted in place to an ADU.

• Note: Conditions apply

No additional parking may be required for a JADU.

• Note: Conditions apply

Parking removed or converted for an ADU does not have to be replaced.

• Note: Conditions apply

No ADU parking standard may be imposed within one-half mile walking distance of public transit.

• Note: Conditions apply

No ADU parking standard may be imposed in an architecturally and historically significant historic district.

• Note: Conditions apply

A pedestrian passageway may not be required for an ADU.

Sprinklers cannot be required in an ADU or JADU if they are not required for the primary residence.

• Note: Conditions apply

For qualifying conversion ADUs and JADUs, a new or separate direct utility connection may not be required except with a new single-family dwelling or separate conveyance.

• Note: Conditions apply

Qualifying conversion ADUs and JADUs cannot be required to install a new direct utility connection, subject to statutory exceptions.

• Note: Conditions apply

A related connection fee or capacity charge cannot be imposed on qualifying conversion ADUs and JADUs, subject to statutory exceptions.

• Note: Conditions apply

Where a private sewage-disposal system is used, local-health-officer approval may be required.

• Note: Conditions apply

A JADU of 500 square feet or less is exempt from impact fees.

• Note: Conditions apply

An ADU or JADU under 500 square feet is treated as construction that does not increase assessable space by 500 square feet for school-fee purposes.

• Note: Conditions apply

The permitting agency must provide written completeness notice within 15 business days.

• In force from: Effective January 1, 2026

A completed ADU or JADU application on a lot with an existing qualifying dwelling must be approved or denied within 60 days; applicant-requested delay tolls the period.

• In force from: Effective January 1, 2026
• Note: Conditions apply

A resubmission addressing listed completeness items is subject to the same 15-business-day completeness timeline.

• In force from: Effective January 1, 2026

A final written determination on an ADU or JADU appeal is due within 60 business days after receipt of the written appeal.

• In force from: Effective January 1, 2026

A local agency has no more than 30 days to respond to HCD findings on a noncompliant ADU or JADU ordinance.

• In force from: Effective January 1, 2026

A completed coastal development permit application for an ADU must be approved or denied within 60 days, subject to the concurrent-primary-dwelling exception.

• In force from: Effective October 10, 2025
• Note: Conditions apply

ADU and JADU permits are reviewed ministerially without discretionary review or hearings.

• In force from: Effective January 1, 2026

For a detached garage replaced by an ADU, written notice or placarding for demolition cannot be required outside an architecturally and historically significant historic district.

• In force from: Effective January 1, 2026
• Note: Conditions apply

An unpermitted ADU or JADU built before January 1, 2020 has a statewide permit pathway, subject to health-and-safety exceptions.

• In force from: Effective January 1, 2026
• Note: Conditions apply

ADU and JADU rentals must be for terms longer than 30 days.

Rentals of 30 days or fewer are not allowed under the statewide ADU/JADU rules.

An ADU or JADU generally may not be sold separately from the primary residence, subject to a statutory separate-conveyance exception not captured by this broad rule.

• Note: Conditions apply

A JADU requires a recorded deed restriction.

• Note: Conditions apply