ADU Permit in San Jose, CA
Permit Summary
ADU Types & Property Eligibility
ADU Type Rules
San José permits attached, detached and conversion ADUs. On a single-family property, the City-standards path allows one attached or detached ADU plus one JADU. The State-standards path allows one new attached or detached ADU, one conversion ADU and one JADU; if a conversion ADU exists or is proposed, the new ADU cannot be attached. Duplex and multifamily properties have separate State-standards allowances for detached and conversion ADUs. A project must use either all City standards or all State standards.
Lot / Zoning Eligibility Rules
ADUs are allowed in areas zoned to allow single-family or multifamily residential use and must be on the same legal parcel as the primary dwelling to which they are accessory. The City's ADU guidance covers single-family, duplex and multifamily properties. Site-specific constraints such as easements, flood zones, geologic hazards, WUI requirements, historic status, fire access and other legally regulated areas can add review or design requirements.
Size, Height & Placement
Setback Rules
Under City standards, the front setback follows the applicable residential zoning-district standard; a new detached ADU is generally behind the main home or at least 45 feet from the front property line. First-story detached ADUs may have 0-foot side and rear setbacks, while a second story requires 4-foot side and rear setbacks; a detached ADU must be at least 6 feet from the main home. Attached ADUs must meet applicable Building and Fire Code separation requirements. Under State standards, a new ADU generally has 4-foot side and rear setbacks, and the front setback may be encroached if necessary to allow a minimum 800-square-foot ADU. Conversion ADUs within existing structures generally retain the existing location, subject to applicable safety requirements.
Lot Coverage / FAR Rules
Under City standards, structures other than swimming pools may cover no more than 40% of the rear yard, subject to the State-law minimum ADU allowances. ADUs that comply with the governing provisions are not considered to exceed the allowable residential density of the lot. Floor-area limits are controlled by the applicable ADU size rules, including the 50% primary-dwelling limit for attached City-standard ADUs. The State-standards table does not impose the City's 40% rear-yard coverage rule on qualifying State-standard units.
Attached ADU Rules
A City-standard attached ADU is subject to the applicable size cap, may be no more than 25 feet high, and the ADU entrance must be on a different facade from the primary dwelling's front door unless an applicable state-law exception controls. It must comply with applicable Building and Fire Code separation and life-safety requirements. Under the State-standards single-family path, a new attached ADU is an alternative to a new detached ADU and cannot be added when an existing or proposed conversion ADU is also being used in that State-standard combination.
Detached ADU Rules
Under City standards, a detached ADU is generally located behind the main home or at least 45 feet from the front property line, must be at least 6 feet from the main home, and is subject to the City size, height, setback and rear-yard-coverage standards. Under State standards, a new detached ADU is generally limited to 800 square feet, has 4-foot side and rear setbacks, and is generally limited to 18 feet plus up to 2 additional feet for a pitched roof. Detached-unit counts differ for single-family and multifamily properties.
Conversion ADU Rules
Existing space or an accessory structure, including a garage or basement, may be converted to an ADU. Under the State-standards single-family path, one conversion ADU can coexist with a new detached ADU and a JADU; up to 150 square feet may be added for ingress and egress. On existing multifamily properties, at least one and up to 25% of existing units may be created by converting qualifying unused spaces. An unpermitted ADU or JADU built or converted before January 1, 2020 may qualify for the City's AB 2533 legalization pathway if the applicant proves the construction date and resolves any substandard conditions.
Design, Occupancy & Parking
Design Standards
City-standard projects on properties listed in the Historic Resources Inventory must follow the simplified historic-property design standards in Municipal Code Section 20.80.175(E). City-standard attached ADUs also have an entrance-facade rule. The current Universal Checklist lists no separate historic-property design standards for qualifying State-standard ADUs, while Building, Fire, energy, CALGreen, flood, WUI and other objective technical requirements still apply where relevant.
Owner Occupancy Rules
Ordinary ADUs are not subject to a local owner-occupancy requirement under current State ADU Law. The March 2026 HCD handbook states that, except for the narrow qualified-buyer separate-sale pathway in Government Code Section 66341, a local agency cannot impose owner occupancy on an ADU. JADUs have separate rules: San José's 2026 checklist states that a JADU with its own sanitation facilities has no owner-occupancy requirement, while shared-sanitation JADUs can require owner occupancy.
Parking Rules
No off-street parking space is required for an ADU under San José's current City or State development standards. The Municipal Code also states that an applicant is not required to replace covered parking removed or demolished to construct an ADU.
Rental / Short-Term Rental Rules
San José allows the primary home and ADU to be rented to different parties. The City's ADU FAQ states that an ADU rental must have a minimum term of 30 days, including Airbnb-type rentals; short-term or transient occupancy for less than 30 days is therefore not allowed for an ADU.
Separate Sale Rules
San José permits an existing or new ADU to be converted to a condominium and conveyed separately from the primary residence through the City's AB 1033 implementation. The project must obtain an approved Parcel Map and comply with Municipal Code Part 2.76, applicable subdivision requirements and the Davis-Stirling common-interest-development rules. Separate conveyance is not an automatic consequence of receiving an ADU building permit.
Address, Utilities & Trade Permits
Address Rules
All ADUs and JADUs receive a separate address assignment as part of the building-permit process. San José requires Form 302 Address Assignment Request. The assigned ADU unit number must be legible and visible from the street fronting the property and must also be posted at the ADU entry for emergency response.
Utility Connection Rules
San José does not itself require a separate utility meter for an ADU, although the City directs applicants to PG&E because PG&E may require a separate electric/gas meter. State law restricts separate water/sewer connections and capacity charges for ADUs created from existing space, while a new connection may be required for other new ADUs subject to proportional connection/capacity charges. The City also requires a water-company hydrant-flow letter for ADU fire review and evaluates electrical-panel and water-service capacity during plan review and inspection.
Trade Permit Rules
Electrical, plumbing and mechanical work must comply with the current 2025 California codes and San José amendments, and project-specific subtrade permits or related permit fees may be required for service upgrades, equipment, gas work, solar/storage or other work outside the approved building-permit scope. The City's ADU inspection checklist specifically evaluates electrical-load capacity and water/plumbing service sizing.
Fire, Energy & Special Requirements
Fire / Life Safety Rules
If the primary residence is protected by fire sprinklers, the ADU must also be sprinklered. San José also requires sprinklers for an attached ADU greater than 500 square feet when the combined gross floor area with the main unit exceeds 3,600 square feet. Plans must address smoke alarms, carbon-monoxide alarms, required fire separation/fireblocking, visible addressing, a fire-access path generally no more than 150 feet from the curb along a minimum 4-foot clear path, hydrant proximity within 600 feet, and a water-company flow letter; flow below 1,000 gpm at 20 psi or inadequate access/hydrant conditions can trigger Fire review, a variance or added safety measures.
Energy / Solar Rules
Applications submitted on or after January 1, 2026 are reviewed under the 2025 California Energy Code and the other 2025 California building codes adopted by San José. The ADU submittal package includes 2025 Title 24 residential energy calculations and mandatory measures plus the 2025 CALGreen checklist. Under current State ADU guidance, a newly constructed detached ADU is generally subject to California Energy Code solar requirements, with exceptions; an ADU created within existing space or as an addition, including conversion of an existing detached nonresidential building, is generally not subject to the solar-system requirement. San José currently states that enforcement of its local natural-gas prohibition is paused, so a detached ADU may be designed with natural gas or all-electric systems.
Special Area / Overlay Rules
Flood zones A, AE, AH and AO trigger the flood-design requirements in Bulletin 211. Geohazard, landslide and certain liquefaction conditions can require Public Works geologic clearance, and WUI properties must comply with the City's WUI fire-conformance requirements. City-standard ADUs on historic properties must follow Section 20.80.175(E). Easements and nonbuildable areas can constrain placement. Tree removal can require separate or concurrent tree review, and heritage trees have special procedures. Projects with these site conditions can also lose eligibility for the preapproved-plan expedited pathway.
Development / Impact Fee Rules
Current State ADU Law, as summarized by HCD in March 2026, exempts an ADU with 750 square feet or less of interior livable space from local-agency, special-district and water-corporation impact fees and requires proportionate impact fees above 750 square feet. San José's current checklist and FAQ state that parkland and school impact fees do not apply below 750 square feet and direct applicants for larger units to the applicable fee process; at the exact 750-square-foot boundary, the controlling State-law exemption applies to local impact fees. School-district fees are governed separately, and the City directs applicants for ADUs of 750 square feet or greater to contact the applicable school district. Taxes, permit-review charges and utility connection/capacity charges are governed separately from impact fees.
Preapproved Plans
Preapproved Plan Rules
San José maintains a preapproved ADU program using standard, non-site-specific plans already reviewed for applicable code compliance. Applicants must still submit site-specific plans and documents for placement, utility connections, setbacks and zoning. The expedited program is limited to residential lots with an existing single-family home or duplex and excludes sites in geohazard, landslide, flood and WUI areas or projects needing specified clearances/variances. Unmodified preapproved plans with a complete site-specific package may qualify for same-day issuance at the scheduled review meeting; modified plans use the standard review path.
Permit & Review Path
Permit / Review Path
Standard ADU applications start through the SJPermits Application Wizard and proceed through SJePlans prescreen, plan review and issuance review. Applicants first complete the Universal Checklist and select either City standards under Section 20.80.175 or the State streamlined standards under Section 20.80.176. Eligible preapproved-plan projects use a site-specific expedited review path. Multifamily applicants are directed to the ADU Ally team for intake assistance. Qualifying unpermitted units built or converted before January 1, 2020 may use the AB 2533 legalization path by emailing the required package to the ADU Ally; the City states that legalization typically takes 4 to 6 months from a complete application.
Inspections
Inspection Stages
Required inspections depend on the approved permit scope and are identified on the permit documents. San José requires the completed Bulletin 213 ADU Inspection Checklist, approved plans and permit card at inspections; new construction commonly includes foundation/slab and structural inspections plus applicable mechanical, electrical and plumbing inspections before final. Construction-and-demolition diversion review must be signed off before the Building Final inspection, and the ADU may be occupied after final approval. If a new main house and ADU are built together, the main house must pass final inspection before the ADU final. AB 2533 legalization uses an initial safety-focused inspection, correction inspections as needed and a final sign-off.
What You Need Before Applying
Requirements
Complete the ADU Universal Checklist, confirm the property and proposed unit are eligible, and choose either the City development standards in Municipal Code Section 20.80.175 or the State development standards in Section 20.80.176; the two standards cannot be mixed. Submit a building-permit application and complete plans through the City's electronic process, comply with applicable zoning, building, fire, energy, CALGreen and site requirements, pay required fees, obtain any project-specific clearances, and pass required inspections before occupancy.
Exemptions
There is no general no-permit exemption for creating an ADU. The State-standards pathway and the City's preapproved-plan program streamline review but still require a building permit. Tiny homes on wheels use a separate City permit/checklist process. Qualifying unpermitted ADUs or JADUs built or converted before January 1, 2020 may use the AB 2533 legalization program, but that pathway also requires a retroactive building permit and inspections.
Required Documents
Typical submittal materials include building plans prepared to Bulletin 211, Form 310 Building Permit Application, Form 312 ADU Property Owner Declaration, Form 302 Address Assignment Request, Bulletin 213 Inspection Checklist for ADUs, 2025 Title 24 residential energy calculations and mandatory measures, and the 2025 CALGreen checklist. A water-company letter showing hydrant flow data is required. A geotechnical investigation, structural calculations, owner-builder form, Fire/Public Works documents, tree information, or other supporting materials may be required depending on the site and scope.