JADU vs ADU: what is the difference for a Los Angeles homeowner?

What is the actual difference between a JADU and an ADU?

The short answer is that an ADU is a full home and a JADU is a small unit inside your house. State law defines an ADU as a unit with complete independent living facilities, including permanent provisions for living, sleeping, eating, cooking and sanitation ¹. It defines a JADU as no more than 500 square feet of interior livable space, contained entirely within a single-family residence, which may have its own bathroom or share one with the house ².

Side by side:

• Size. A JADU tops out at 500 square feet ². A detached ADU can be up to 1,200 square feet under state law ¹⁰, and a city cannot cap an attached or detached ADU below 850 square feet, or 1,000 square feet with more than one bedroom ¹¹.
• Where it goes. A JADU must be built within the walls of the house ³. An ADU can be attached or detached ¹, and it can also be made from existing space such as a garage ²⁵.
• Kitchen. A JADU needs at least an efficiency kitchen ⁷. An ADU needs a full set of living facilities, cooking included ¹.
• Bathroom. A JADU may share the house's bathroom ². An ADU has its own sanitation ¹.
• Owner on site. A JADU with a shared bathroom requires the owner to live on the property ⁴. An ADU cannot carry an owner-occupancy requirement ⁹.

Can I put a JADU in my garage or in the backyard?

You can put a JADU in an attached garage, but not in a detached garage or anywhere in the backyard. State law treats enclosed spaces within the house, such as an attached garage, as part of the house for JADU purposes ³. HCD's handbook says plainly that JADUs are not allowed in accessory structures ¹⁴.

So on a typical Valley ranch house, the realistic JADU spots are a bedroom wing with an outside door, a den off the side yard, or an attached two-car garage. A detached garage at the back of the lot is a garage conversion ADU instead, and we cover how to check its permit history in How to check if your LA garage was permitted.

You also do not have to choose. Only one JADU is allowed per single-family lot ¹⁵, but state law requires cities to allow at least one ADU made from existing space, one JADU and one new detached ADU on a single-family lot ²⁵. What fits on a typical lot is laid out in What size ADU fits on a 6,600 sq ft lot.

Do I have to live in the house if I add a JADU?

Only if the JADU shares a bathroom with the house. As of January 2026, state law requires owner-occupancy when the JADU has shared sanitation facilities, and says owner-occupancy is not required when the JADU has its own ⁴¹². The owner can live in either the rest of the house or the JADU itself ⁴. A regular ADU cannot be tied to owner-occupancy at all ⁹.

Two things stay the same whichever way you build it:

• A recorded deed restriction. The JADU cannot be sold separately from the house, and the restriction can be enforced against future buyers ⁵.
• No short stays. If you rent the JADU, the term has to be longer than 30 days ⁸.

One thing to watch in Los Angeles: City Planning's ADU memo, dated August 2025, still says the house with a JADU must be owner occupied, without the bathroom distinction ²¹. That text predates the January 2026 change. If you plan a JADU with its own bathroom and do not plan to live there, ask LADBS which wording its deed restriction will use before you design around it.

What kind of kitchen and entrance does a JADU need?

A JADU needs at least an efficiency kitchen and its own entrance. State law defines the efficiency kitchen as a cooking facility with appliances, plus a food preparation counter and storage cabinets of reasonable size for the unit ⁷. It also requires an entrance separate from the house's main entrance ⁶.

The bathroom changes the layout. If the JADU does not have its own bathroom, it must also have an interior door to the main living area, so the occupant can reach the shared bathroom ⁶.

On the kitchen, the state and the city do not read the same way:

• HCD says a local agency cannot be more restrictive than the state definition, and that counter or cabinet sizes, specific electrical or gas connections, or appliance types are not authorized by state JADU law ¹³.
• City Planning's memo says the cooking facility needs at least two appliances, which can be small plug-in ones like a microwave and hotplate ¹⁹.
• The LADBS ADU and JADU bulletin, revised August 2026, lists a kitchen sink, cooktop and refrigerator, each with 30 inches of clear space in front, as the minimum provisions for cooking ²².

Plan for the LADBS list unless plan check tells you otherwise, because LADBS is the office that signs off the plans. A sink usually means a new drain line inside the wall, which is a bigger change than a counter and a microwave. The Fire Department also requires a separate address for every separate residential unit, JADUs included ²⁰.

Is a JADU cheaper to permit than an ADU?

Usually yes, in fees and city requirements, though this guide does not quote prices. A JADU of 500 square feet or less carries no impact fees, and neither does an ADU of 750 square feet or less ¹⁷. Both ADUs and JADUs are exempt from LA's Park Fees and Affordable Housing Linkage Fee ²³. School fees are a separate question, covered in ADU school fees and LAUSD.

The bigger savings are in what a JADU does not trigger:

• No parking. A city cannot require parking for a JADU, even one converted from an attached garage ¹⁶.
• No new utility service. City Planning says a JADU is not a separate dwelling unit for water, sewer or power service, including a connection fee ¹⁹. A new detached ADU can be required to get its own connection, which is why LADWP water meter costs for an ADU matter for a backyard house and not for a JADU.
• No fire sprinklers, unless the house has them. State law says sprinklers are not required for a JADU when the house does not have them, and adding a JADU cannot trigger them ¹⁸.

Plans, construction and the rest of the soft costs still apply. For those, see ADU soft costs in Los Angeles.

How many Valley homeowners actually build a JADU?

Very few. In 2025, LADBS issued 75 building permits for JADUs in the 35 City of LA San Fernando Valley ZIP codes we track, against 3,110 for ADUs ²⁴. From January 1 through October 3, 2026, the count was 44 JADUs and 2,353 ADUs ²⁴. That is fewer than one JADU for every 40 ADUs.

We read that as a choice about space more than about rules. A JADU gives up 500 square feet of the house you live in, while a backyard house or garage conversion uses space you are not living in. A JADU makes the most sense when the house is larger than the household, when a grown child or a parent needs a door of their own, or when the backyard is ruled out by an easement, a protected tree or a long sewer run. For the ZIP-by-ZIP ADU picture, see ADU permits in the Valley by ZIP.

Whether your house has a wing that can become a JADU, and whether the backyard can take an ADU instead or as well, is the kind of thing a lot check settles.

Quick answers

Sources

1. Government Code section 66313(a): definition of accessory dwelling unit, State of California (text via California.Public.Law). Facts checked 2026-10-09
2. Government Code section 66313(d): definition of junior accessory dwelling unit, State of California (text via California.Public.Law). Facts checked 2026-10-09
3. Government Code section 66333(d), State of California (text via California.Public.Law). Facts checked 2026-10-09
4. Government Code section 66333(b), State of California (text via California.Public.Law). Facts checked 2026-10-09
5. Government Code section 66333(c)(1), State of California (text via California.Public.Law). Facts checked 2026-10-09
6. Government Code section 66333(e), State of California (text via California.Public.Law). Facts checked 2026-10-09
7. Government Code section 66333(f), State of California (text via California.Public.Law). Facts checked 2026-10-09
8. Government Code section 66333(g), State of California (text via California.Public.Law). Facts checked 2026-10-09
9. Government Code section 66315, State of California (text via California.Public.Law). Facts checked 2026-10-09
10. Government Code section 66314(d)(5), State of California (text via California.Public.Law). Facts checked 2026-10-09
11. Accessory Dwelling Unit Handbook (March 2026): Size Requirements and Restrictions, California Department of Housing and Community Development. Facts checked 2026-10-09
12. Accessory Dwelling Unit Handbook (March 2026): AB 1154, California Department of Housing and Community Development. Facts checked 2026-10-09
13. Accessory Dwelling Unit Handbook (March 2026): efficiency kitchen, California Department of Housing and Community Development. Facts checked 2026-10-09
14. Accessory Dwelling Unit Handbook (March 2026): JADUs in accessory structures, California Department of Housing and Community Development. Facts checked 2026-10-09
15. Accessory Dwelling Unit Handbook (March 2026): number of JADUs per lot, California Department of Housing and Community Development. Facts checked 2026-10-09
16. Accessory Dwelling Unit Handbook (March 2026): JADU parking, California Department of Housing and Community Development. Facts checked 2026-10-09
17. Accessory Dwelling Unit Handbook (March 2026): impact fees, California Department of Housing and Community Development. Facts checked 2026-10-09
18. Accessory Dwelling Unit Handbook (March 2026): JADUs and fire sprinklers, California Department of Housing and Community Development. Facts checked 2026-10-09
19. ZA Memorandum No. 143, Revision 1 (August 1, 2025): JADUs required to be approved by State law, Los Angeles Department of City Planning, Office of Zoning Administration. Facts checked 2026-10-09
20. ZA Memorandum No. 143, Revision 1: JADU address, Los Angeles Department of City Planning, Office of Zoning Administration. Facts checked 2026-10-09
21. ZA Memorandum No. 143, Revision 1: JADU owner occupancy, Los Angeles Department of City Planning, Office of Zoning Administration. Facts checked 2026-10-09
22. Information Bulletin P/BC 2026-150, Accessory and Junior Accessory Dwelling Units (revised 08-13-2026): Interior Environment, LADBS. Facts checked 2026-10-09
23. Information Bulletin P/BC 2026-150: fees, LADBS. Facts checked 2026-10-09
24. LADBS Building Permits dataset (Greenlight query), City of Los Angeles Open Data. Facts checked 2026-10-09
25. Accessory Dwelling Unit Handbook (March 2026): combinations on a single-family lot, California Department of Housing and Community Development. Facts checked 2026-10-09

Greenlight is not a contractor, architect or engineer, and this is not legal advice. Rules change; every fact here shows the date we last checked it.