Prefab Accessory Dwelling Units in California
We install faster and smarter prefab accessory dwelling units in California that homeowners trust. You will get high-quality prefab ADUs, designed off-site, installed efficiently, and built to last.
4.9/5 rating from 56+ online reviews.
A Better Way to Build Your ADU
Prefab ADUs are changing how homeowners add space. Instead of long, unpredictable construction timelines, a prefabricated ADU is built in a controlled environment and then installed on your property, saving time without cutting corners.
Whether you’re exploring a modular ADU, comparing ADU kits, or looking for affordable prefabs, the goal is the same: a clean, efficient build with fewer delays.
From rental units to private living spaces, pre-built and pre-made ADU homes give you flexibility. At Sidex, we guide you through every option so you don’t just pick what’s available, you choose what actually works for your property and your goals.
Complete Prefab ADU Solutions
Custom Prefab ADU Planning
Not all prefab ADUs are one-size-fits-all. We help you choose the right size, and features, whether you’re looking for a compact unit or a spacious ADU modular home in California that feels like a full home.
Prefabricated ADU Installation
We handle the full installation of your pre-built ADU, including site preparation, foundation work, and utility connections. Our team ensures your prefabricated ADU is installed safely and correctly.
Modular & Manufactured ADU Options
From modular ADU builds to manufactured ADU units, we offer a range of solutions tailored to different budgets. If you’re searching for the best prefab ADU, we’ll help you find the right balance between cost, quality, and design.
Built with Precision, Designed for Real Living
Explore our projects to see how we build functional, durable, and visually seamless structures across Northern California.
How We Build Your Detached ADU
Consultation & Feasibility
We evaluate your property, zoning, and goals to determine what type of detached ADU makes the most sense for your space and budget.
Step 1
Design & Planning
Our team creates a custom design, including layout, materials, and utility planning. We also handle permit documentation and approvals.
Step 2
Construction
From foundation to final finishes, we manage the entire detached ADU construction process with a focus on quality, timelines, and clean execution.
Step 3
Final Walkthrough
We complete final inspections, ensure everything is code-compliant, and walk you through your new space so it’s ready for immediate use.
Step 4
Detached ADU Builders Across Northern California
We design and build detached ADUs for homeowners across key regions, serving over 57 locations.
The Bay Area
From San Francisco to San Jose and surrounding cities, we help homeowners create smart, space-efficient ADUs that increase property value and usability.
South Lake Tahoe
In mountain regions, we build detached ADU construction projects designed for weather durability, insulation, and year-round comfort.
Sacramento Region
Serving Sacramento, Roseville, and nearby areas, we deliver practical and cost-effective detached ADUs tailored to growing families and rental opportunities.
Detached ADU FAQs
What is a detached ADU?
A detached ADU is a separate residential unit built on the same property as your main home, fully independent with its own living facilities.
How is a detached ADU different from an attached ADU?
A detached dwelling stands alone, offering more privacy and flexibility compared to attached units that share a wall with the main home.
How long does detached ADU construction take?
Timelines vary, but most projects take a few months depending on design complexity, permits, and site conditions.
Can I rent out my detached ADU?
Yes. Many homeowners use detached ADUs as rental units for additional income, subject to local regulations.
Do I need permits for a detached ADU?
Yes. Every detached additional dwelling unit must meet local zoning and building requirements. We help manage this entire process.
