What Kitchen Does an ADU Need? Full vs Efficiency

Quick answer

An ADU kitchen is the permanent cooking area that, together with a place to sleep and a bathroom, makes an accessory dwelling unit a separate home rather than an extra room.

In California, a full ADU must include permanent provisions for cooking. A junior ADU may have a smaller efficiency kitchen: a cooking appliance, a prep counter and storage cabinets.

Quick facts

Full ADU (CA): Permanent provisions for cooking and eating ¹
Junior ADU (CA): Efficiency kitchen: cooking facility with appliances, prep counter, storage cabinets ²
Efficiency unit (CA): A city may allow partial kitchen facilities by ordinance ³
Sink (model code): Every kitchen area needs a sink ⁴
Room size (model code): Kitchens are exempt from the 70 sq ft habitable-room minimum ⁴
Why it matters: A kitchen is a main test of whether space is a dwelling unit ¹

What it means, in plain English

A kitchen is what turns a room into a home. Add a bed and a bathroom to a space, and you have a guest suite. Add a place to cook, and you have a separate dwelling.

That is why the kitchen is the line the law watches. California defines an ADU as a unit with permanent provisions for living, sleeping, eating, cooking and sanitation ¹. No cooking, no ADU.

There are two sizes of kitchen in the ADU world. A full ADU gets a full kitchen. A junior ADU may have a smaller one, called an efficiency kitchen.

Key takeaways

Cooking facilities are part of the legal definition of an ADU in California ¹.
A junior ADU needs only an efficiency kitchen: a cooking appliance, a counter and cabinets ².
The model code requires a sink in every kitchen area ⁴.
Adding a kitchen to a guest room or pool house can make it a dwelling unit that needs an ADU permit.
Gas or electric, and the panel size, are often the cost drivers.
Some local codes push new units toward all-electric cooking.

Why it matters to you

The kitchen decides what you are building, legally. A room with a kitchen may be an ADU. Without one, it is usually an accessory structure or part of the house.

That changes the permit, the fees and the rules. It is also why an unpermitted kitchen in a garage or pool house can cause trouble at sale time.

And it decides cost. Cabinets, appliances, a vent, a sink drain and a circuit for the range all add up. A smaller kitchen can save money where the law allows it.

Kinds of ADU kitchen

California categories from Gov. Code §§ 66313 and 66333 and Health and Safety Code § 17958.1, read 8 October 2026.
Kind	Used in	What it must have
Full kitchen	A full ADU	Permanent provisions for cooking ¹, plus a sink under the model code ⁴
Efficiency kitchen	A junior ADU	A cooking facility with appliances, and a prep counter and storage cabinets of reasonable size ²
Partial kitchen	An efficiency unit, if the city’s ordinance allows	What the local ordinance specifies ³
Wet bar	Not a dwelling unit	A sink, often no cooking; local codes decide when it becomes a kitchen

Rules: what California law says about ADU kitchens

Current text read on leginfo on 8 October 2026.
Topic	What the law says	Section
ADU definition	An ADU shall include permanent provisions for living, sleeping, eating, cooking and sanitation	Gov. Code § 66313(a) ¹
Efficiency unit is an ADU	An ADU also includes an efficiency unit	Gov. Code § 66313(a)(1) ¹
JADU kitchen	An efficiency kitchen: (1) a cooking facility with appliances; (2) a food preparation counter and storage cabinets of reasonable size for the unit	Gov. Code § 66333(f) ²
Efficiency unit kitchen	A city may, by ordinance, allow units of at least 150 sq ft for up to two people, with partial kitchen or bathroom facilities	Health and Safety Code § 17958.1(a) ³

Efficiency kitchen, in plain words

The law lists three things for a junior ADU kitchen. A cooking facility with appliances. A counter to prepare food. Cabinets to store it. Counter and cabinets must be “of reasonable size” for the unit ².

The law we read does not list a sink, an oven or a set number of burners for a JADU kitchen. Your city’s ordinance and building code fill in details. The model code’s rule that every kitchen area has a sink is one of them ⁴.

So a compact setup, such as a two-burner cooktop, a small counter and a sink with cabinets below, often fits. Ask the city what it accepts as a “cooking facility.” Use the checklist below on your junior ADU plans.

Checklist Junior ADU efficiency kitchen: what to show on the plans

A cooking facility with appliances, named on the floor plan ²
A food preparation counter of reasonable size for the unit ²
Storage cabinets of reasonable size for the unit ²
A kitchen sink, which the model code requires in a kitchen area ⁴
A circuit for each cooking appliance on the electrical sheet
Ventilation as your adopted code requires
The city’s written answer on what it accepts as a “cooking facility”

California junior ADU rule plus model-code basics. Your city’s ordinance and adopted code fill in the rest. Source: [2] [4]

Sources: [2]

How an ADU kitchen gets planned

Pick the unit type. Full ADU or junior ADU decides full or efficiency kitchen.
Choose the fuel. Gas or electric. Check local all-electric rules first.
Check the panel. An electric range or induction cooktop needs its own circuit.
Place the sink near the drain path, ideally sharing a wall with the bath ⁴.
Plan ventilation. A range hood as your adopted code requires.
Size the counter and storage for the people who will live there.
Show it all on the plans. Appliances, circuits and fixtures.

Worked example: one room, three outcomes

A hypothetical permitted 300 sq ft room off a California house, with its own outside door and bathroom. What the owner adds decides what it is.

Owner adds	What it becomes	Why
Nothing	Part of the main house	No cooking provisions, so not a dwelling unit ¹
A cooktop, prep counter and cabinets	Can be permitted as a junior ADU	Meets the efficiency kitchen list ²; under 500 sq ft ¹
A full kitchen	Can be permitted as a JADU or a full ADU	Either type works; the deed and owner rules differ

Important distinction

A wet bar is a sink. A kitchen has permanent provisions for cooking. Adding cooking to a room with its own door and bathroom can turn it into a dwelling unit in the law’s eyes, and that needs a permit ¹.

In each case, the kitchen needs a building permit. Adding one without a permit can leave an unpermitted unit. See unpermitted ADU research.

Kitchen layouts that suit small units

Common layout shapes. No sizes are given, since room sizes vary with each plan.
Layout	How it works	Best for
One-wall	Sink, cooktop and fridge along a single wall	Studios and junior ADUs; easiest to plumb
Galley	Two facing runs of counter with a walkway between	Narrow units that need more counter
L-shape	Counters on two walls meeting at a corner	One-bedroom units with an open living room
Island or peninsula	Adds a counter that doubles as a table	Larger units; skip it if floor space is tight

Where you will see it

On the floor plan: the kitchen drawn with each appliance.
On the electrical plan: range, refrigerator and counter circuits.
On the permit form: “full” or “efficiency” kitchen for a JADU.
On a city letter about a guest house: a kitchen is often why a city calls it a second unit.
On the appraisal: a second kitchen is noted.

Rules outside California

Nearly every state and city treats a kitchen as a sign of a separate dwelling. The efficiency kitchen for a junior ADU is California’s category, though some cities elsewhere allow similar small units.

Some places ban second kitchens in single-family homes unless permitted as an ADU. Check local rules. Start with ADU laws by state.

Costs and what drives them

We do not quote a typical ADU kitchen price. These are the drivers. See ADU electrical panel for the power side.

Size: efficiency kitchen vs full kitchen.
Fuel: running a gas line, or adding electric capacity.
Panel upgrade, if the service cannot carry new loads.
Drain and vent for the sink.
Cabinets, counters and appliances.

Full vs efficiency kitchen: benefits and limits

Full kitchen

Suits long-term living and families.
Wider tenant appeal.
Works for a full ADU or a JADU.

Efficiency kitchen

Saves space and money.
Allowed for a junior ADU ².
Less storage and counter space.
May feel tight for long-term use.

ADU kitchen compared with related terms

Term	Cooking?	Status
Full ADU kitchen	Yes, permanent	Required for a full ADU ¹
Efficiency kitchen	Yes, compact	Enough for a junior ADU ²
Kitchenette in a guest room	Often	May create a dwelling unit that needs an ADU permit
Wet bar	No	Usually not a dwelling unit
ADU gas connection	—	Fuel supply for a gas range

Common mistakes

Myth A junior ADU needs a full kitchen.: Reality It needs an efficiency kitchen ².
Myth A microwave alone makes an efficiency kitchen.: Reality The law lists a cooking facility with appliances, a counter and cabinets ². Ask the city what counts.
Myth A kitchenette in a guest house is fine without a permit.: Reality A kitchen can make the space a dwelling unit. Many cities require an ADU permit.
Myth A kitchen must be 70 sq ft like other rooms.: Reality The model code exempts kitchens from that minimum ⁴.

What to ask the city and your designer

What appliances does the city accept as a JADU “cooking facility”?
Does my area have all-electric rules for new units?
Can my panel carry an electric range?
Where can the sink drain tie in?
Does adding a kitchen to my guest house require an ADU permit?

Checklist for the ADU kitchen

Decide full or efficiency kitchen.
Check fuel rules and panel capacity.
Place the sink by the drain path.
List every appliance on the plans.
Plan the range hood.
Permit the kitchen with the unit.

Related guides, tools and research

ADU designCompact kitchen layouts
All-electric reach codesWhere gas is limited
Electrical service upgradesWhen the panel must grow
ADU type selectorJADU or full ADU?

Questions about adu kitchen

Does an ADU need a kitchen?

Yes. In California, an ADU must include permanent provisions for living, sleeping, eating, cooking and sanitation. Without cooking facilities, a space is not a separate dwelling unit. A junior ADU may use a smaller efficiency kitchen instead of a full one.

What is an efficiency kitchen?

It is the kitchen a California junior ADU must have. The law lists a cooking facility with appliances, a food preparation counter, and storage cabinets of reasonable size for the unit. Your city may add details through its ordinance and building code.

Does a junior ADU need a full kitchen?

No. A California junior ADU needs only an efficiency kitchen: a cooking facility with appliances, a prep counter and storage cabinets. You may install a full kitchen if you like, but it is not required for a JADU.

Does an ADU kitchen need an oven?

California’s ADU law, as we read it, does not list an oven. A full ADU needs permanent cooking provisions, and a JADU needs a cooking facility with appliances. What appliance counts is decided locally, so ask your building department before you choose.

Does an ADU kitchen need a sink?

Under the 2024 International Residential Code, every kitchen area must have a sink. Most states and cities build on that model code. Your local adopted code confirms the rule and adds details on drains and venting.

Can I add a kitchen to my guest house?

Often, but it usually means permitting the guest house as an ADU. A kitchen is a main sign of a separate dwelling. Adding one without a permit can create an unpermitted unit, which may cause problems with insurance, sale or the city.

Can an ADU have a gas stove?

It depends on local rules. Some California cities have adopted reach codes that limit gas in new buildings. Elsewhere, gas is allowed if a line can be run. Check your city’s current energy and building rules before you design.

Is a kitchenette enough for an ADU?

For a junior ADU in California, a compact efficiency kitchen is enough. For a full ADU, the law requires permanent provisions for cooking. A city may also allow partial kitchens in efficiency units by ordinance. Ask how your city reads “kitchenette.”

How big does an ADU kitchen need to be?

There is no state minimum size we found for an ADU kitchen. The model code exempts kitchens from the 70 square foot minimum for habitable rooms. For a JADU, counter and storage must be of reasonable size for the unit.

Does the kitchen affect ADU fees?

Not directly under California’s ADU law, which ties impact fees to size ⁵. But a kitchen adds plumbing and electrical loads. A larger electric load may need a panel or service upgrade, which brings its own costs.

Sources

California Legislature, Gov. Code § 66313, definitions, retrieved October 8, 2026.
California Legislature, Gov. Code § 66333, junior ADUs (as amended by AB 1154, Stats. 2025, ch. 507), retrieved October 8, 2026.
California Legislature, Health and Safety Code § 17958.1, efficiency units, retrieved October 8, 2026.
International Code Council, 2024 International Residential Code, Chapter 3 Building Planning (R312.1, R326.2), retrieved October 8, 2026.
California Legislature, Gov. Code § 66311.5 (formerly § 66324; renumbered by SB 543), retrieved October 8, 2026.

Expert review

Written by the HyreADU Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.

How the numbers were checked: State rules read from Gov. Code §§ 66313 and 66333 and Health and Safety Code § 17958.1 on leginfo, and kitchen rules from the 2024 IRC on the ICC site, 8 October 2026.

Suggest a correction. We fix errors and say what changed.