Can I Build ADU in San Jose, CA? (2026)
Find out if you can build a adu in San Jose, CA. Rules, permit requirements, costs, and next steps.
Yes, ADUs are allowed in San Jose, CA. California state law ensures by-right approval.
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a residential lot — also called a granny flat, in-law suite, or backyard cottage. In San Jose, CA, ADUs are permitted by right under state law, making them one of the most accessible ways to add housing on your property. ADUs can be detached, attached to the main home, or created by converting an existing garage or accessory structure.
ADU Rules in San Jose
ADU Rules in San Jose: Detached ADU max size: 1200 sq ft. Attached ADU max size: 50% of primary dwelling up to 1200 sqft. Junior ADU (JADU): up to 500 sq ft, within existing structure. Setbacks: 4 ft side, 4 ft rear. Owner-occupancy: Owner-occupancy requirement eliminated statewide effective January 1, 2020 per AB 68 (Gov Code 65852.2(a)(6)). No owner-occupancy required for primary dwelling or ADU.. State preemption applies: CA law requires San Jose to approve compliant ADUs by right.
Costs & Fees
ADU permits in San Jose: Total estimated permit cost: $2,500–$8,500 total permit fees depending on size and scope. Contact the San Jose Department of Planning, Building and Code Enforcement (PBCE) — Building Division for current fee schedule.
Timeline
Ministerial approval within 60 days per Gov Code 65852.2(a)(3). San Jose PBCE (Planning, Building and Code Enforcement) ADU permits typically 3-6 weeks plan check. Online permit portal: https://www.sanjoseca.gov/your-government/departments-offices/planning-building-code-enforcement/building
Next Steps
Next steps for building an ADU in San Jose: 1. Review full ADU rules including size limits, setbacks, and parking. 2. Apply for an ADU permit through the San Jose Department of Planning, Building and Code Enforcement (PBCE) — Building Division at https://www.sanjoseca.gov/your-government/departments-offices/planning-building-code-enforcement/building/online-permit-services. 3. Hire a licensed contractor familiar with CA ADU requirements.
San Jose Department of Planning, Building and Code Enforcement (PBCE) — Building Division
Frequently Asked Questions
Can I build an ADU in my backyard in San Jose?
Yes. California state law requires San Jose to permit ADUs by-right on all residential lots. You can build a detached ADU up to 1,200 sqft, or a Junior ADU (JADU) up to 500 sqft within your existing home. No owner-occupancy requirement applies. San Jose is one of the most ADU-active cities in California due to its housing shortage. Permits are processed ministerially within 60 days.
What are San Jose's short-term rental rules?
San Jose requires short-term rental registration ($200/year) for all rentals under 30 days. Your property must be your primary residence. Transient Occupancy Tax (10%) applies to all short-term rental income. Register with San Jose Finance Department before listing on any platform. Airbnb collects and remits TOT on behalf of qualifying hosts.
What zoning is needed for a single-family home in San Jose?
Most single-family homes in San Jose are in R-1-6 (6,000 sqft minimum lot) or R-1-8 (8,000 sqft minimum lot) zones. These zones allow one primary dwelling plus ADUs per state law. Front setback is 20 ft, side yards 5 ft, and rear yard 20 ft. Building height is limited to 30 ft (2 stories). Check your specific zone at the San Jose GIS Portal: gisportal.sanjoseca.gov.
Do I need a permit to run a business from my home in San Jose?
Yes. A Home Occupation Permit ($200) is required for any business operated from a San Jose residence. Restrictions include: no clients on-site, no non-resident employees, no exterior signs. Business use must be incidental to residential use. Silicon Valley's startup culture makes home occupation permits very common in San Jose.
Are solar panels required on new homes in San Jose?
Yes. California's Title 24 Energy Code requires solar PV on all new low-rise residential construction. San Jose has one of the highest solar adoption rates in the US. PG&E net metering is available under NEM 3.0. SolarAPP+ provides expedited permits for standard residential systems. San Jose's 300+ sunny days per year make solar highly cost-effective.
What are San Jose's ADU setback requirements?
New detached ADUs in San Jose require 4-foot side and rear setbacks per California state law (Gov Code 65852.2). No setback is required for an ADU that replaces an existing structure in the same footprint (e.g., garage conversion). Front setbacks follow the applicable zone standards — typically 20 ft for R-1 zones. No minimum ADU lot size requirement.
How do I find the zoning for my property in San Jose?
Use the San Jose GIS Portal at gisportal.sanjoseca.gov to look up your parcel's zone designation, overlay districts, and development standards. You can also call San Jose PBCE at (408) 535-3555 or visit the public counter at 200 E. Santa Clara Street for zoning verification.
Source: San Jose Department of Planning, Building and Code Enforcement (PBCE) — Building Division — Building Regulations. Last verified April 5, 2026. View source