Kitchens for ADUs, Garage Conversions and Junior Units

California has spent several years reducing the barriers to building accessory dwelling units, and the result across San Diego County is a great deal of garage conversion, junior unit and detached casita work. The kitchen is the part of that work most often underestimated, because it looks like a small version of a normal kitchen and behaves like something else entirely.

Why the kitchen defines the unit

An accessory dwelling unit is required to include permanent provision for living, sleeping, eating, cooking and sanitation. The cooking provision is what separates a dwelling from a bedroom with a sink in it, which makes it a legal requirement rather than an amenity. What specifically satisfies that requirement, in terms of appliance and utility provision, is confirmed by the permitting authority, and for a Chula Vista address that is the city Development Services Department.

The practical implication is that this question belongs at the start of the design, because the answer affects the layout, the services and the plan submission, not the finish schedule.

Two different projects

A full ADU kitchen

In a detached unit or a substantial conversion, this is a compact version of everything on the rest of this site: cabinetry, counter, sink, range, ventilation and the circuits to run it all, usually along one or two walls. The specification decisions are the same as any kitchen. The layout decisions are not, because there is one wall to work with rather than three.

A kitchenette

In a junior unit or a smaller conversion, a single run with a compact range or cooktop, a smaller sink and under-counter refrigeration. Smaller in every dimension, and correspondingly less forgiving: every inch of counter has a job, and there is nowhere to put something that was not planned for.

What is different from a normal kitchen

The services usually do not exist yet

A small kitchen inside an existing house already has drainage, a vent, gas or an adequate circuit, and a route to the outside. A detached ADU or a garage conversion frequently has none of those. The project therefore includes getting supply, waste and power to the building before any kitchen work begins, and on a detached unit that can be the larger half of the number. The cabinetry is the visible part and often the smaller part.

Electrical is sized for the whole unit

The load calculation is not just the kitchen, it is the entire dwelling: cooking, refrigeration, water heating, heating and cooling, and lighting. That has to be supplied either from the main house panel, which needs assessing for capacity, or by a separate service. Angi puts a panel upgrade at $520 to $2,000 in its June 2026 figures, and on an ADU project that is frequently in scope.

The ventilation route has to be invented

The state ventilation requirements apply to dwelling units, and an ADU is a dwelling unit, so the range hood airflow requirement is live. In a converted garage or a detached structure there may be no existing duct penetration at all, and the wall or roof assembly may not have been designed with one in mind. Settling that route on the drawing is worth more than choosing the hood. The ventilation guide covers the options.

Garage conversions specifically

Garages present three recurring problems, all of them solvable and all of them costing something.

• The floor slopes. Garage slabs are poured with a fall toward the door by design, so a level finished floor means either a raised, framed floor above the slab or a levelling pour.
• The slab is at a different level from the house. Which matters for the threshold, for headroom once the floor is raised, and for how drainage runs.
• There is rarely a drain. A kitchen sink needs waste and vent, and in a garage that usually means cutting the slab and connecting to the house drain.

Where the conversion is being done properly, with insulation, a raised and levelled floor and full services, a complete kitchen is entirely realistic. It is worth pricing the conversion and the kitchen as one project rather than two, because the sequencing between them is where money gets wasted.

Designing a small kitchen well

• Maximise unbroken counter. Two feet of continuous work surface is worth more than four feet split into three pieces by a sink and a cooktop.
• Size the sink down, not up. A single large bowl with a small drainer usually beats a double bowl in a short run, because the double bowl consumes counter and gives you two small sinks instead of one usable one.
• Compact appliances. A 24-inch range instead of 30, an 18-inch slimline or 24-inch dishwasher, and under-counter or apartment-height refrigeration. Confirm actual dimensions before the cabinets are drawn.
• Go vertical. Small kitchens run out of floor long before they run out of wall, so cabinetry to the ceiling is close to mandatory rather than an upgrade.
• Drawers over doors. In a small kitchen the difference between a base cabinet you have to kneel at and a drawer that brings its contents out is disproportionately large.
• Check the door swings. In a compact run, an oven door, a dishwasher door and a refrigerator door can each block the only circulation route.

Where to start

1. Confirm with the permitting authority what the cooking provision has to include for your unit type.
2. Establish where services can come from and what that route costs, before designing the kitchen around a wall.
3. Settle the ventilation route on the drawing.
4. Choose the appliances early and design the cabinetry to their real dimensions.
5. Price the conversion and the kitchen as one scope with one sequence.

Next

The ADU kitchen service page covers what the work involves, the permits guide covers which authority you are dealing with, and the cost guide carries the published figures for each line.

For a real number, call (619) 754-4257 or use the quote form for a free quote.