Detached ADU
Standalone unit in your backyard. Up to 1,200 sq ft. Perfect for maximum privacy and rental potential. Popular in Los Angeles, San Diego, and the Bay Area.
California ADU Experts
Turn Your Property into an Investment
California's progressive ADU laws have made it easier than ever to add an Accessory Dwelling Unit to your property. Whether you're looking to generate rental income, house family members, or increase your property value, an ADU is one of the smartest investments you can make in today's California real estate market.
At Andalusia Drafting, we specialize in creating permit-ready ADU plans that comply with California state regulations and your local jurisdiction's requirements. From initial consultation to permit approval, we guide you through every step of the design process.
State-Compliant Designs
All ADU Types
Title 24 Included
Fast Turnaround
Title 24
Included in every ADU set
ADU Options
Types of ADUs We Design
California allows several types of ADUs. We create permit-ready plans for all of them.
Garage Conversion
Transform your existing garage into a living space. Cost-effective option using existing structure. No additional lot coverage needed.
Attached ADU
Extension connected to your main home. Up to 1,200 sq ft or 50% of existing living area. Ideal for multigenerational living arrangements.
Junior ADU (JADU)
Up to 500 sq ft within existing home footprint. Converted bedroom, garage, or storage area. Most affordable ADU option.
Know the Rules
California ADU Regulations
California has streamlined ADU regulations to address the housing crisis. Here's what you need to know.
State ADU Standards
- Size Limits: Detached ADUs up to 1,200 sq ft; Attached up to 1,200 sq ft or 50% of primary dwelling
- Setbacks: 4-foot side and rear setbacks for new construction; no setbacks for conversions
- Height: Up to 16 feet for detached ADUs (18 feet in some cases)
- Parking: No parking required for ADUs in most cases
- Owner Occupancy: Not required for ADUs permitted after January 1, 2020
- Impact Fees: Waived for ADUs under 750 sq ft
Your Permit Set
What You Receive, Sheet by Sheet
Every ADU set is prepared for your city's submittal requirements and delivered as a print-ready PDF.
Sheet
Title
What's on it
01
Cover Sheet & Site Plan
Project data, scope of work, area breakdown, setbacks, applicable codes, and vicinity map
02
General Notes
California Residential Code, CALGreen, plumbing, and energy notes your building department expects
03
Floor Plans
Existing and proposed layouts, fully dimensioned, with wall legend and door and window callouts
04
Elevations & Sections
Exterior views, heights, materials, and egress notes, plus sections where required
05
Electrical & Mechanical Plan
Lighting, outlets, smoke and CO alarms, exhaust fans, and controls
06
Title 24 Energy Sheets
CF1R and mandatory measures, calculated in CBECC and included in every ADU set
+
Structural
Coordinated with a California-licensed engineer when your project requires it
Andalusia Drafting · ADU Permit Set
Sheet count varies by project
Local Expertise
ADU Drafting by California City
Every city has unique requirements, and we check yours before drafting begins.
Los Angeles ADU
LA's Standard Plan Program offers pre-approved ADU designs. We can customize these or create fully custom plans. LA allows ADUs up to 1,200 sq ft with streamlined permitting. Converting a garage? See our LA garage conversion plans.
San Diego ADU
San Diego offers expedited review for ADUs under 1,200 sq ft. The city has been a leader in ADU-friendly policies.
San Francisco ADU
SF's unique lot conditions require careful design. We work with the city's ADU programs and understand historic district requirements and density bonus provisions.
San Jose ADU
San Jose has embraced ADUs with supportive policies. We help homeowners navigate South Bay requirements for both new construction and garage conversions.
Orange County ADU
OC cities like Irvine, Anaheim, and Santa Ana each have specific guidelines, and we check your city's before drafting begins.
Sacramento ADU
Sacramento's ADU program supports affordable housing goals. We design ADUs that meet the Capital Region's requirements and maximize your property's potential.
How It Works
Our ADU Design Process
01
Free Consultation
Discuss your ADU goals, property conditions, and budget. We'll explain your options and local requirements.
02
Site Analysis
We review your property, zoning, setbacks, and any restrictions that may affect your ADU design.
03
Design Development
Custom ADU design tailored to your needs. We handle floor plans, elevations, and all technical drawings.
04
Permit Package
Complete permit-ready documents including Title 24 compliance for submission to your building department.
Common Questions
ADU FAQs
An ADU (Accessory Dwelling Unit) is a secondary housing unit on a single-family residential lot. Also known as granny flats, in-law suites, or backyard cottages, ADUs have become extremely popular in California due to state laws that make them easier to build, the ongoing housing shortage, and their potential for rental income or multigenerational living. California passed laws in 2016 and subsequent years to streamline ADU construction statewide.
California state law allows detached ADUs up to 1,200 square feet regardless of lot size. Attached ADUs can be up to 50% of the primary dwelling's living area or 1,200 square feet, whichever is less, but at minimum 800 square feet is allowed. Junior ADUs (JADUs) are limited to 500 square feet and must be within the existing home footprint. Some cities may have additional allowances, so we always check local regulations for your specific project.
ADU construction costs in California typically range from $150,000 to $400,000+ depending on size, finishes, site conditions, and location. Garage conversions are generally the most affordable option starting around $100,000-$150,000. New detached ADUs cost more due to foundation, utility connections, and full construction. Our drafting services are a fraction of total construction costs and are essential for obtaining permits and accurate contractor bids.
You get a first preview in 7–10 business days, and when the design needs only light changes, ADU plans are typically permit-ready in 2–3 weeks. Each review round adds time, and your quote confirms your schedule. Permit processing times vary by city—California law requires cities to approve ADU permits within 60 days of a complete application. Some cities with high ADU volume may take longer. We design plans that minimize revision requests to help speed up your approval.
California law (AB 670, effective January 2020) prohibits HOAs from completely banning ADUs. HOAs can have reasonable restrictions regarding design, aesthetics, and landscaping, but they cannot unreasonably restrict construction. If your HOA has concerns, we can design ADUs that meet both state requirements and reasonable HOA guidelines.
For ADUs permitted after January 1, 2020, California state law does not require owner occupancy. This means you can rent out both your main home and your ADU. Note that Junior ADUs (JADUs) do have an owner-occupancy requirement—the owner must live in either the main home or the JADU. Some cities may have different rules, so we verify requirements for your specific location.
Ready to Build Your California ADU?
Get a free consultation and quote for your ADU project. We'll help you understand your options and create permit-ready plans.
You work directly with Younes Hatti, founder of Andalusia Drafting LLC, from first quote to permit approval.