How much does an ADU really cost in California?
A clear breakdown of soft costs, hard costs, and the line items that move your budget the most.
Read →Your property has
more to give.
Casita is a design-build studio turning backyards and unused garages into permitted, beautiful living space — one team, start to finish.
(01)Approach
Our approach to ADUs and garage conversions
The space was always there. We just finish it — designed well, permitted properly, built once.
An extra bedroom for family. A rental that covers the mortgage. A studio to work from. The answer rarely means moving. It means using what you already own, and doing it right the first time — drawings, engineering, the city, and construction handled under one roof.
(02)What We Build
What we build
A
Accessory Dwelling Units ↗
Detached studios and one- or two-bedroom homes, fully independent and built to California ADU code — for rental income, family, or simply more room.
B
Garage Conversions ↗
Already framed, roofed, and connected — we turn an unused garage into permitted living space for a fraction of the cost and time of building new.
(03)Process
Our process, from design to move-in
01
Design
We measure your lot, learn how you'll use the space, and design a unit that fits your property and budget.
02
Permits
Drawings, engineering, and the city — from start to approved permit, fully managed on your behalf.
03
Build
One crew, one fixed schedule, clear weekly updates. You always know exactly where the project stands.
04
Move In
Final inspection, walkthrough, keys. A finished, permitted home — ready to live in or rent out.
(04)Configurations
Configurations and starting prices
Pick your space. Price it instantly.
Starting prices for our most-requested builds. The same garage becomes very different rooms — so the number that matters is the one for what you want.
A — Garage ConversionsUsing your existing garage
Most chosen
Bed + Bath Suite
A private bedroom and full bathroom — our most-requested conversion.
From $30k8–10 wks
Servants' Quarters
A self-contained suite for live-in staff — bedroom, bath, and a private entrance.
From $38k9–11 wks
Home Office
A quiet, finished workspace fully separated from the main house.
From $26k6–8 wks
Home Gym
Reinforced floors, mirrors, and ventilation built for a real workout.
From $34k7–9 wks
Recording Studio
Sound-isolated walls and treated acoustics for music or podcasts.
From $46k9–12 wks
Guest Suite + Kitchenette
Bedroom, bath, and kitchenette — ready for guests or short-term rental.
From $52k10–12 wks
Full Garage ADU
Independent living — full kitchen, bathroom, and laundry, permitted.
From $78k12–16 wks
B — Detached ADUsNew build in your yard
Studio ADU
A new detached studio with kitchen and bath — compact and complete.
From $145k4–6 mo
Most chosen
1-Bedroom ADU
A new detached one-bed home — the sweet spot for rental income.
From $185k5–7 mo
2-Bedroom ADU
A full two-bed, two-bath detached home for family or long-term tenants.
From $265k6–9 mo
Starting prices for planning only. Final pricing is confirmed after a free in-home visit — it depends on your structure and finishes.
Selected work.
(05) — A growing portfolio across California
Journal.
(06) — Notes on building smarter
(07)FAQ
Frequently asked questions
How much does an ADU cost in California?
With Casita, a garage conversion starts around $26k for a home office and runs to about $78k for a full garage ADU. A new detached ADU starts around $145k for a studio, $185k for a one-bedroom, and $265k for a two-bedroom. Final pricing is confirmed after a free in-home visit and depends on your structure and finishes.
What is an ADU?
An accessory dwelling unit (ADU) is a self-contained second home on the same lot as a primary residence — with its own kitchen, bathroom, and entrance. Homeowners build ADUs for rental income, to house family, or simply for more living space.
How long does a garage conversion take?
Most Casita garage conversions take 6–16 weeks depending on scope, from a simple home office to a full garage ADU. New detached ADUs typically take 4–9 months from design to move-in.
Does Casita handle the permits?
Yes. Casita manages the entire process — design, engineering, and city permitting — through to an approved permit and final inspection, all under one roof. You don't deal with the city; we do.
What areas does Casita serve?
Casita is a design-build studio serving homeowners throughout California.
Can a garage conversion be rented out?
Yes. A permitted garage conversion or ADU can be used as a long-term or short-term rental — one of the most common reasons California homeowners build one.
Find out what your lot can hold.
Tell us your address and what you're imagining, and we'll send a specialist to your home to walk the space with you — free, no obligation.
Book your free visit →