The short answer is a kitchen. Under California law, if a backyard structure has permanent provisions for cooking, it’s an accessory dwelling unit (ADU) and you can legally rent it out. No kitchen, and it’s a guest house. In most California cities that means you can’t rent it to anyone, at any price, for any length of time.
That one distinction changes what you’re allowed to build, what you can charge, and what the structure does for your property value. Here’s what Long Beach and Signal Hill homeowners should know before breaking ground.
The legal definition, in plain English
California Government Code §66313 defines an accessory dwelling unit as a residential unit that “provides complete independent living facilities for one or more persons.” To qualify, it needs permanent provisions for five things:
- Living
- Sleeping
- Eating
- Cooking
- Sanitation
A guest house checks some of those boxes. There’s a place to sleep, usually a bathroom, often a sitting area. What’s missing is the kitchen, and that gap is exactly what keeps it classified as an accessory structure instead of a dwelling unit.
This isn’t a technicality contractors invented. It’s the line the state draws, and it’s the line your city’s building department will apply when they review your plans.
Side-by-side comparison
| ADU | Guest House | |
|---|---|---|
| Kitchen | Required | Not permitted |
| Can be legally rented | Yes | No |
| Counts as a dwelling unit | Yes | No |
| Permit path | Ministerial (by-right) | Accessory structure permit |
| Adds rentable square footage to appraisal | Yes | Generally no |
| Typical build cost | Comparable | Comparable |
That last row surprises most homeowners. A guest house usually costs about the same to build as an ADU. Same foundation, same framing, same roof, same electrical and plumbing rough-in. You’re spending ADU money either way. The only question is whether you end up with something that can pay you back.
Why this matters financially
Three things follow from that kitchen.
Rental income. You can lease an ADU to a tenant. You can’t lease a guest house. If part of your reason for building is offsetting the mortgage or setting up retirement income, a guest house closes that door permanently.
Appraisal treatment. Appraisers count a permitted ADU as additional living area. An unpermitted structure, or one that isn’t a dwelling unit, usually doesn’t get the same credit. Sometimes an unpermitted conversion actually works against you at sale.
Resale disclosure. If someone quietly added a kitchen to a guest house without pulling permits, that becomes a disclosure problem the day you list the house, and a negotiating lever for the buyer.
Building an ADU in Long Beach
Long Beach allows ADUs by right in all residential zones (R-1, R-2, R-3, R-4, and planned development zones). A few specifics worth knowing before you start planning:
- Maximum size for a detached ADU: 1,200 sq ft
- Setbacks: 4 feet
- Parking: Not required within a half mile of transit, or for conversions of existing space
- Permit fees: Typically $3,000 to $10,000
- Coastal Zone: Properties inside Long Beach’s Coastal Zone need a coastal development permit on top of the standard city approvals, so build in extra review time
Long Beach also runs a pre-approved ADU plan program. Picking a city-vetted plan shortens plan check and cuts your design costs. Ask about it before you commission custom drawings.
Rules change and they vary parcel by parcel. Confirm the specifics for your address with Long Beach Development Services, Planning Bureau, at (562) 570-6194. Or ask us and we’ll pull it for you.
What about a JADU?
The junior accessory dwelling unit gets overlooked, and it shouldn’t. A JADU runs up to 500 square feet and sits entirely within the walls of an existing single-family home. Think of a converted primary bedroom. It needs an efficiency kitchen, but it can share a bathroom with the main house.
One 2026 change is worth flagging. Under AB 1154, effective January 1, 2026, a JADU only triggers an owner-occupancy requirement if it shares sanitation facilities with the primary home. Give the JADU its own bathroom and that requirement goes away.
If you’ve got more house than you need, a JADU is often the fastest and cheapest route to a legal rental unit.
Can you convert a guest house into an ADU?
Usually yes, and it’s typically cheaper than building new since the foundation, walls, and roof are already standing.
What it takes is bringing the structure up to current code as a dwelling unit. That means adding a compliant kitchen, confirming the bathroom meets requirements, and pulling building, electrical, and plumbing permits. The snags we run into most often are ceiling height, undersized electrical service, and structures that were built without permits to begin with.
That last one deserves a straight warning. If the original guest house was never permitted, this stops being a simple upgrade. The city may want walls opened for inspection, and in some cases the answer is demolish and rebuild. It’s still frequently worth doing. You just want to know that going in, not halfway through.
Frequently asked questions
Can I rent out a guest house in California?
No. Without permanent cooking provisions it isn’t a dwelling unit, so you can’t legally rent it short-term or long-term. Adding a kitchen without permits doesn’t fix the problem. It creates an unpermitted dwelling unit, which is worse.
Is a casita the same as a guest house?
“Casita,” “granny flat,” “in-law suite,” and “pool house” are marketing terms, not legal ones. California doesn’t care what you call it. It cares whether the structure has permanent provisions for cooking and sanitation.
Does an ADU have to have a full kitchen?
A standard ADU needs permanent cooking provisions. A JADU can get by with an efficiency kitchen, meaning a sink, cooking appliance, counter, and storage, though cities define “efficiency kitchen” differently.
Will an ADU raise my property taxes?
Adding an ADU triggers a reassessment of the new construction only. Your existing Prop 13 basis on the main house stays where it is.
Thinking about building in Long Beach or Signal Hill?
De Sisto Construction has been building in the Greater Long Beach, Los Angeles, and Orange County area since 2001. We handle ADU projects from permits through move-in day, including the upfront conversation about whether an ADU, a JADU, or a conversion actually makes the most sense for your lot and your budget.
Call 562-425-1050 for a free estimate, or request one online.
De Sisto Construction, Inc. Licensed General Contractor, CA License #803545. Signal Hill, CA.
This article is general information, not legal advice. ADU rules vary by city and by parcel. Confirm requirements for your specific property with your local planning department before making decisions.