ADU vs JADU vs movable tiny home vs accessory structure: the LA homeowner's comparison

Four legal categories in LA can give you "a second small dwelling on the property." They get confused all the time. They're not the same. Costs, permits, kitchen rules, sale rules, and who can live there differ across all four. Here's how to tell them apart and pick the right one.

The 60-second version: Pick a full ADU for rental income or max property value. Pick a JADU if you have spare interior space and want in-laws. Pick a movable tiny home for reversible backyard housing. Pick an accessory structure for a workshop or office without plumbing. Anything else, run your address through the wizard.

Quick answer

Category	Max size	Kitchen	Owner must occupy primary?	Sellable separately?	LA permit fees	Build cost
Full ADU (detached or attached)	1,200 sqft (detached) / 50% of primary (attached)	Required (full kitchen)	No	Only if city opts into AB 1033	$8K-$20K	$150K-$350K+
JADU (Junior ADU)	500 sqft	Efficiency kitchen only	Yes (one of the two units)	No	$3K-$8K	$25K-$100K
Movable tiny home (RV-class on wheels)	~400 sqft typical	Yes (RV/HCD-certified)	Varies by city	No	$1K-$5K (site work)	$40K-$150K
Accessory structure (non-habitable)	Per setback rules	None (no plumbing)	N/A	No	$500-$3K	$5K-$50K

The deeper differences are below. Pick by what you actually need: rental income (ADU or JADU), in-laws (JADU often easier), portable backyard housing (tiny home), or extra workshop or office without plumbing (accessory structure).

Full ADU (Accessory Dwelling Unit)

• What it is: a complete, code-compliant second residential unit on the same parcel as a single-family or multi-family primary dwelling. Three sub-types: detached (separate building), attached (sharing a wall with the primary), and conversion (converting existing space like a garage or basement). Defined under California Government Code §65852.2 (originally AB 68, 2019).
• Max size: 1,200 sqft detached. Attached ADUs are capped at 50% of the primary dwelling's floor area, with a state floor of 800 sqft minimum that cities must allow. Conversion ADUs follow the existing structure's footprint with no statutory cap.
• Kitchen and bath: full kitchen (sink, stove, oven, refrigerator, food prep counter) and full bathroom (toilet, sink, shower or tub) required.
• Owner-occupancy: not required for new ADUs permitted on or after January 1, 2020. State law preempts local owner-occupancy mandates.
• Setbacks: 4 feet from side and rear lot lines (state preemption, cities cannot require more). Front-yard setbacks remain governed by underlying zoning.
• Parking: zero off-street parking required if the property is within half a mile of a major transit stop. Otherwise, one off-street space per unit, which can be tandem or in setback areas.
• Plan check: full LADBS plan check. PRADU plans get 5-20 day turnaround. Custom plans 60-120 days. See LADBS plan check pipeline.
• LAUSD school fee: $4.79/sqft on ADUs over 750 sqft. Under 750 sqft, fully exempt by state law.
• Rental: yes for long-term (over 30 days). Short-term rentals including Airbnb are typically banned by city ordinance; verify your specific jurisdiction.
• Separate sale: only in cities that have opted in to AB 1033 (2023). LA City has not opted in as of 2026.
• When to pick this: rental income, multi-generational housing with full independence, or maximum property value uplift. Full ADUs typically add $150K-$300K to property value in LA depending on size and finish.

AB 1033 watch: LA City Council has discussed but not adopted AB 1033 as of May 2026. If they do, your ADU becomes a separately-deeded condo that can be sold without the primary dwelling. Major financing and resale implications. Track this if you're building now.

JADU (Junior Accessory Dwelling Unit)

• What it is: a subordinate unit within an existing single-family dwelling. Codified under California Government Code §65852.22. Created by carving out existing interior space and adding an exterior entrance plus an efficiency kitchen. Cannot be built as a new detached structure.
• Max size: 500 sqft. State-set, no local override.
• Kitchen and bath: efficiency kitchen only (small sink, cooking facility, food prep counter, but no full-size oven or range required). Bath access can be shared with the primary dwelling or private.
• Owner-occupancy: required. The owner must live in either the primary dwelling or the JADU. This is the only small-unit category that still carries this requirement under California state law.
• Setbacks: N/A. The JADU is carved from existing space; no new exterior walls are added.
• Parking: zero off-street parking required. State preemption applies. Cities cannot require additional parking for a JADU.
• Plan check: simpler than full ADU. Fewer reviewers (Zoning clears quickly, no Mechanical since no separate HVAC, no separate Electrical sub-permit in most cases). 2-4 weeks typical.
• LAUSD school fee: exempt. JADUs are under the 750 sqft threshold.
• Rental: yes for long-term (30+ days). Owner-occupancy of one unit still required even when JADU is rented.
• Separate sale: no. JADUs are legally part of the primary dwelling and cannot be sold separately.
• When to pick this: in-laws or adult children housed with privacy, or modest rental income from existing footprint without taking on a $200K+ build. JADUs work best when there's existing under-used interior space (extra bedroom, oversized garage, attic, basement) that can be converted.

Movable tiny home (RV-class on wheels)

• What it is: a factory-built dwelling unit on a permanent chassis with wheels, certified under either RV (Recreational Vehicle Industry Association) or California HCD standards. Distinct from a "tiny ADU." Classified as a vehicle, not a structure, and permitted under different rules. AB 1410 (2022) requires HOAs and cities to permit one qualifying movable tiny home as accessory living in residential zones.
• Max size: ~400 sqft typical, constrained by towable highway width (8'6" max) and practical length limits. No statutory state cap.
• Kitchen and bath: required. Built to RV or HCD standards rather than residential building code.
• Owner-occupancy: varies. AB 1410's qualifying movable tiny home is meant as accessory living for family members or close associates, not commercial rentals. Local ordinances may further restrict.
• Setbacks: same as accessory structures or RV parking rules per local zoning. Often less restrictive than ADU setbacks since the unit is movable.
• Parking and connections: connected to existing primary dwelling's utilities via temporary or quick-disconnect couplings. Must remain registered with the DMV (RV plate) or HCD (HCD-titled tiny home).
• Plan check: no LADBS plan check on the unit itself. Site work permits required for any new utility lateral connections. $1,000-$5,000 typical site-work permit budget.
• LAUSD school fee: not applicable. Not a permitted dwelling.
• Rental: generally not for short-term commercial use. Long-term occupancy by family members or close associates is the model. Some cities permit limited extended-stay rentals.
• Separate sale: yes. The tiny home is personal property (titled like a vehicle) and can be sold separately from the underlying land. The buyer takes the unit with them.
• When to pick this: reversible housing for an aging parent or adult child, a writer's studio you might tow to another property, or low-investment backyard housing without committing to permanent construction. Resale value is real but it's a vehicle, not real estate.

Watch the wheels: if you remove them or set the unit on a permanent foundation, it loses movable status and becomes a permitted structure subject to full ADU rules. That conversion is a one-way door. Plan accordingly.

Accessory structure (non-habitable)

• What it is: a permitted structure on the property not intended for habitation. Examples: detached garage, workshop, studio without plumbing, storage shed, pool house without a kitchen, garden office. Cannot be slept in legally. Cannot be rented as living space.
• Max size: governed by setbacks and lot coverage rules. Up to 1,000 sqft is typically straightforward on most R1 lots. Larger structures may trigger conditional use review.
• Kitchen and bath: none permitted. The moment you add a kitchen or a full bath, it becomes a habitable structure and triggers full ADU plan check.
• Owner-occupancy: N/A. Not a dwelling.
• Setbacks: per underlying zoning. Detached accessory structures typically need 5-foot side and rear setbacks (more than the 4-foot ADU rule).
• Parking: N/A.
• Plan check: simpler than residential. No Electrical sub-permit if no power, no Plumbing if no water connections. Often a single building permit covering the entire scope. 2-3 weeks typical.
• LAUSD school fee: exempt.
• Rental: no. Cannot be rented as habitable space.
• Separate sale: no.
• When to pick this: workshop, storage, gym, or office space without the construction cost or regulatory weight of an ADU. Useful as a stepping stone. Many accessory structures are built first, then later legalized into ADUs by adding plumbing and kitchens (which retroactively triggers a permit conversion process that varies in difficulty).

Decision shortcut

Looking for rental income? Full ADU.

Housing in-laws with the lowest cost? JADU (if you have convertible interior space).

Reversible housing for a family member? Movable tiny home.

Workshop or office only? Accessory structure.

The PermitPathLA wizard's feasibility step shows which of these categories are viable on your specific lot, factoring in setbacks, overlays, and existing structures. Run your address through it before committing to a path that won't pencil out.

Common confusions

"My garage already has a sink and a half-bath. Is it a JADU?" Probably no. JADUs require an efficiency kitchen and must be within the primary dwelling, not in a detached garage. A garage with plumbing is typically a non-habitable accessory structure unless converted under full ADU rules. If the city catches habitation in such a space, expect a cease-and-desist and a path to either remove the plumbing or convert to a permitted ADU.

"Can I park a tiny home and call it an ADU?" No. A movable tiny home is a vehicle, not an ADU. State law treats them as distinct categories. If you want the tiny-home aesthetic with full ADU benefits (rental income, legal habitability, property value addition), you build a small permitted ADU on a permanent foundation, not a unit on wheels.

"What about a 'shed conversion'?" A shed becomes habitable space the moment you sleep in it, regardless of what the structure looks like. Sheds-as-rentals are illegal habitation. Make it permitted (full ADU process) or accept it stays a shed.

"Can I rent out my JADU on Airbnb?" Generally no. LA's short-term rental ordinance restricts STRs to the host's primary residence (Home-Sharing Ordinance). A JADU could qualify if the owner occupies the primary dwelling and rents the JADU short-term, but local rules vary and HSO compliance is strict. Long-term (30+ days) is the cleaner path for any ADU or JADU.

This is the legal landscape. The PermitPathLA wizard runs your specific lot through these categories and tells you which paths are open before you spend a dollar on plans.

Caveats

Rules above reflect California Government Code §65852.2 and §65852.22, AB 1033 (2023), AB 1410 (2022), and LAMC §12.22 A.33 as of May 2026. State ADU law has changed every legislative session since 2017 and will keep changing. AB 1033 opt-in status in LA City specifically can flip; verify current local opt-in with LA City Planning before assuming an ADU is sellable separately from the primary dwelling. Cost ranges reflect typical 2026 LA conditions; your specific project can fall outside them based on lot conditions, finish level, and contractor selection. Always verify current rules with LADBS or the relevant building department for your jurisdiction.