Attached and Detached ADU Construction in Los Angeles
Attached and Detached ADU Construction
in Los Angeles
Expert ADU Construction for Expanded Living Spaces
If you’re considering attached and detached ADU construction in Los Angeles, Cala Builders offers full-service design and build solutions that expand your living spaces, increase square footage, and maximize the potential of your single-family property. Whether you want a detached ADU in the backyard or an attached ADU connected to your home, our experienced team handles every aspect of your ADU project with expertise, clear communication, and dependable results.
Adding an ADU, whether for a rental unit, guest housing, or a dedicated home office, can enhance your property and create long-term value. We help homeowners navigate the permit process, refine ADU design, and complete construction that meets city codes and your personal goals.
What Are Attached and Detached ADUs?
Attached ADUs are secondary living units that share at least one wall with the main home. They are integrated structurally and can be more efficient in terms of utilities and design. Detached ADUs are standalone units, often referred to as granny flats or backyard cottages, that sit separately on the lot and offer complete privacy.
Both types of ADUs are legal in Los Angeles under current regulations. Many homeowners choose ADUs to:
- Provide a rental unit for long-term income
- Create space for extended family or adult children
- Add a home office or creative studio
- Convert an existing garage into a livable unit through garage conversion
- Add guest housing or a private suite for visitors
No matter your goals, our team can help you build an ADU that fits your lifestyle and property features.
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Licensed, insured, and trusted by property owners across Los Angeles County (License #1156496). Speak with a Cala Builders specialist to discuss your goals and receive a clear project scope and cost estimate, no pressure, no obligation.
Transparent Pricing
ADU Construction Cost in Los Angeles
ADU pricing in LA varies by type, size, site conditions, and finish level. The table below covers realistic starting points for each ADU type Cala Builders constructs across Los Angeles County. All prices include design, permits, and full construction.
| ADU type | Starting price | Typical range | Best for |
|---|---|---|---|
| Garage Conversion ADU Best valueFastest and most affordable ADU path using your existing garage structure | $85,000 | $85K – $140K | Homeowners with an existing attached or detached garage seeking the fastest, most affordable ADU path |
| Junior ADU (JADU)Converting an existing room within the primary home into a separate unit | $90,000 | $90K – $150K | Converting an existing room or portion of the primary home into a separate unit with its own entrance |
| Attached ADU Most popularA self-contained unit added to and connected with the main home | $110,000 | $110K – $200K | Adding a self-contained unit connected to the main home, ideal for multigenerational living or rental income |
| Detached ADUA fully standalone backyard structure with maximum privacy | $140,000 | $140K – $280K | A standalone backyard structure offering maximum privacy, with the strongest rental income potential in LA |
| Two-Story Detached ADUFull apartment-style unit maximizing square footage on smaller lots | $200,000 | $200K – $380K | Maximizing square footage on smaller lots, a full apartment-style unit with upper and lower floors |
| Hillside ADU PremiumEngineered for sloped or canyon lots with specialized foundation work | $180,000 | $180K – $350K | Sloped or canyon lots requiring engineered foundations, retaining walls, and site-specific structural planning |
What’s included in every Cala Builders ADU price: Site analysis, custom architectural design, all city permit fees and filing, foundation, framing, plumbing, electrical, HVAC, insulation, drywall, flooring, interior finishes, and final inspection sign-off. No hidden costs.
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Licensed, insured, and trusted by homeowners across Los Angeles County (License #1156496). Talk to an ADU specialist general contractor and find out exactly what your ADU will cost.
ADU Cost by Square Footage
Not sure which ADU type fits your budget? Use this size-based breakdown to estimate costs before committing to a configuration. All ranges reflect Los Angeles market pricing including design, permits, and full construction by Cala Builders.
| Size | Estimated Cost Range | Best ADU Type |
|---|---|---|
| 400 sq ft | $85K – $120K | Garage conversion / JADU |
| 500 sq ft | $95K – $140K | Attached / garage |
| 600 sq ft | $110K – $160K | Detached / attached |
| 800 sq ft | $130K – $210K | Detached |
| 1,000 sq ft | $155K – $250K | Detached |
| 1,200 sq ft | $180K – $320K | Two-story detached |
Los Angeles allows detached ADUs up to 1,200 sq ft. Larger units typically offer better cost-per-square-foot value. Final pricing depends on site conditions, finish level, and utility connections.
What affects your ADU cost in Los Angeles
01. Size & square footage
Larger ADUs cost more per project but less per sq ft. LA allows up to 1,200 sq ft for detached ADUs.
02. Foundation type
Slab foundations are the most affordable. Hillside or raised foundations add $15K–$60K depending on soil and slope.
03. Finish level
Standard finishes keep costs at the lower end. Premium appliances, custom tile, and high-end fixtures add $20K–$60K.
04. Lot conditions
Access, soil type, utility proximity, and existing structures on the lot all impact site preparation costs.
05. Permit complexity
Most LA permits are streamlined under SB 9 and SB 13. Complex lots or HOA oversight may require additional review.
06. Utility connections
Separate meter, new sewer lateral, or panel upgrade can add $8K–$25K depending on distance and capacity needed.
Types of ADUs We Build
Benefits of ADU Construction in Los Angeles
Our ADU Construction Process
Initial Consultation and Planning
Every project begins with an in-depth consultation. We listen to your goals and assess your property to determine the best ADU type for your needs. This includes reviewing zoning and lot conditions to understand limitations and opportunities.
ADU Design and Permitting
Our design team prepares plans that reflect your vision and comply with local regulations. We handle the permit process with the Department of Building and Safety and other relevant agencies, ensuring your project meets all legal requirements before construction begins.
Construction and Project Management
Our experienced builders follow a structured construction process that includes foundation work, framing, electrical and plumbing, insulation, and finishes. We provide professional project management to keep your build on schedule and within budget. We coordinate subcontractors, materials, inspections, and quality checks to ensure your ADU is built right.
Final Walkthrough and Delivery
Once construction is complete, we will conduct a final walkthrough with you. We ensure everything works as expected and that you understand how to use and maintain your new space.
Why Choose Us as Your ADU Contractor
Selecting the right team for attached and detached ADU construction in Los Angeles is essential for a smooth, successful project. Homeowners trust Cala Builders because we:
- Offer high-quality construction with attention to detail
- Provide clear communication and dependable customer service
- Work closely with clients throughout the design, permitting, and build phases
- Understand local building codes and permit requirements
- Deliver ADUs that meet aesthetic and functional goals
Our goal is to make your ADU project efficient, enjoyable, and rewarding. We want you to feel confident in every decision from initial concept to final inspection.
Frequently Asked Questions
What sizes can ADUs be in Los Angeles?
ADU sizes vary based on lot size and zoning. We help you understand parameters and design units that maximize usable space.
How long does ADU construction take?
Projects differ in timeline, but most ADU builds take several months from design to completion, including permitting and inspections.
Do ADUs require a separate address?
In many cases, yes. Your ADU may receive a separate address for utility and rental purposes, depending on local guidelines.
Can a detached ADU be rented long term?
Yes. Detached ADUs can serve as long-term rental units, subject to local rules and tenant regulations.
Get Started With Your ADU Construction
If you are ready for professional attached and detached ADU construction in Los Angeles, our team is here to help. From initial design to move-in-ready living spaces, we deliver results that enrich your property and expand your options.
📞 Call us today to schedule a consultation and begin building the ADU that fits your vision and goals.
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Have a question? Get in touch
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