San Jose is Abodu’s number-one city: 52 completed backyard homes and counting, with 109 across the South Bay. See the San Jose market page for the model mix, rental math, and install timelines.
Two Ways To Permit An ADU In San Jose.
Every San Jose ADU is permitted under one of two rulebooks: the city's own local development standards, or the default standards guaranteed by California state law. You pick one track, not both, and the right choice depends on your lot and how big you want to build. Most permits are approved in three to four months, and the city's ADU program offers pre-approved plans that speed things up further.
San Jose Local Standards
- Detached ADUs up to 1,000 Sq Ft on lots of 9,000 Sq Ft or less, and up to 1,200 Sq Ft on larger lots
- One-story units up to 18 ft tall; two-story units allowed
- More generous sizing, with city-specific design standards
California State Standards
- Detached ADUs up to 800 Sq Ft on any lot size
- Heights of 16 ft by default, 18 ft near transit or on multifamily lots, up to 20 ft with a matching roof pitch
- Guaranteed approval framework set by state law
On lots with an existing home, an ADU generally can't exceed 50% of the primary residence's size, but state law guarantees you room to build regardless: at least 850 Sq Ft for a one-bedroom or 1,000 Sq Ft for a two-bedroom, even where that exceeds the 50% cap.
Who Can Build, And How Many.
ADUs are allowed on any San Jose lot with an existing or planned single-family or multifamily home. On a single-family lot you can add one ADU plus one junior ADU (JADU); the ADU can be detached, attached, or a garage conversion, while the JADU (up to 500 Sq Ft) lives within the home itself.
Multifamily properties can add up to eight detached ADUs (capped at the number of existing units), plus interior conversions, which is exactly the opportunity our Multifamily program is built around, complete with an underwriting calculator for operators.
Setbacks, Conversions, And Special Zones.
New detached ADUs need just 4-foot side and rear setbacks under the state framework. Converting an existing structure, like a garage, carries no new setback requirements at all. Extra standards can apply in flood, fire, seismic, or historic overlay zones; the city's ADU Universal Checklist is the official reference, and it's the paperwork we handle for you.
A First In The Nation: Sell Your ADU Under AB 1033.
In 2024 San Jose became the first U.S. city to let homeowners sell a backyard ADU separately from the main residence as a condominium. The authority comes from AB 1033 (2023), a state law that lets cities opt in to ADU condominium sales, and San Jose opted in first.
What that changes: an ADU in San Jose is no longer only a rental. Once converted under the city's AB 1033 process, the unit can carry its own title and be sold on its own, like a condo, while you keep the main house. The conversion follows California's condominium framework, which means recording a condominium plan and getting the consent of any lender with a lien on the property, so plan the paperwork alongside the build. For an investor or a homeowner thinking about equity, that is a second exit: rent the unit, house family, or sell it separately down the road.
It also compounds the math on our San Jose market page: a backyard home that nets rent at an 8%+ yield on cost and can later be sold as its own condominium is a different asset class from a garage conversion. Talk to a title company or real estate attorney about the conversion steps before you count on a separate sale; the build itself is the easy part.
What It Actually Costs.
Custom site-built ADUs in California routinely run past $250,000, and that's before the change orders. Abodu works differently: transparent published pricing: homes from $234,800 plus a published installation price, for an expected all-in total from $298,800, locked in your agreement before construction starts. See how the process works from feasibility check to move-in day, with on-site installation as fast as one day.