How San Jose Handles Accessory Structures: A Practical Guide
San Jose maintains 199 local ordinances across all categories, and 5 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where San Jose falls on the strict-to-permissive spectrum compared to other cities.
Shed & Carport Rules
San Jose treats carports as open accessory structures under Table 20-70: a 60-foot front setback, no side or rear setback, and a 12-foot height cap in residential districts, unless it qualifies as a garage instead.
Key details: Front setback: 60 feet from front property line. Side/rear setback: None, except corner/key lots. Height limit: 12 feet, one story. Size cap: 650 sq ft cumulative (SUP above).
Building a carport within the 60-foot front setback, over the 12-foot height limit, or beyond the 650-square-foot cumulative accessory cap without a special use permit risks a stop-work order and code enforcement action by PBCE.
Garage Conversions
San Jose lets homeowners convert an existing garage into livable space by treating it as an accessory dwelling unit, with no floor-area cap and no requirement to replace the lost covered parking anywhere else on the lot.
Key details: No floor-area cap: for converting existing garage to ADU. Setbacks: existing garage setbacks may be kept. Parking replacement: not required for the lost garage space. Facilities required: full kitchen and full bathroom. Governing rule: SJMC § 20.80.175, Accessory Dwelling Units.
Converting a garage into a bedroom, in-law unit, or rental space without an ADU building permit, or without the required kitchen, full bathroom, and Building/Fire Code compliance, is unpermitted construction subject to correction orders from the city's Building Division.
Tiny Homes
San Jose allows one Tiny Home on Wheels per single-family lot under SJMC § 20.30.495, with rear-yard placement, a paved pad, utility hookups, and a detailed design checklist.
Key details: Max per lot: One THOW. Rear yard setback: 4 ft sides/rear, 10 ft corner. Distance from main house: 6 feet minimum. Max height: 16 feet, 2 stories. Governing code: SJMC § 20.30.495.
Placing a THOW without meeting the setback, hookup, and design standards makes it a code-enforcement violation for an unpermitted accessory structure; removing the wheels and setting it on a foundation instead triggers full ADU permitting under § 20.80.175.
ADU Rental Restrictions
San Jose lets homeowners rent an accessory dwelling unit long-term, but Municipal Code § 20.80.160 flatly bars incidental transient occupancy, stays under 30 days, inside an ADU, so short-term hosting must stay in the primary residence.
Key details: Governing section: SJMC § 20.80.160. ADU short-term rentals: Flatly not allowed. ADU long-term rentals: Allowed, legal status protected. Transient occupancy threshold: 30 consecutive days or less. STR still allowed in: Primary home or guest house.
Running a short-term rental (Airbnb-style stays under 30 days) out of an ADU is an unpermitted use citywide, enforceable through San José's standard zoning code enforcement process regardless of hosting-platform listing status.
Compared to other cities, San Jose takes a harder line on adu rental restrictions. The enforcement and penalty structure reflects that.
ADU Rules
San Jose allows one accessory dwelling unit plus one junior ADU on any single-family lot by right, capping floor area at 1,000 to 1,200 square feet and requiring no side or rear setback under Municipal Code § 20.80.175.
Key details: Max floor area: 1,000-1,200 sq ft by lot size. Side/rear setback: 0 feet for new construction. Height limit: 18 ft one-story, 25 ft two-story. Parking required: None for the ADU itself. Units on single-family lot: 1 ADU plus 1 junior ADU.
Building an ADU larger than the 1,000/1,200 square-foot cap, encroaching into the required setbacks, or skipping the building permit exposes the structure to a stop-work order and possible removal until it complies or is permitted after the fact.
The Bottom Line
San Jose's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming San Jose is broadly strict or permissive.
Keep in mind that San Jose can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.