ADU Construction Services Across Southern California
Trusted by Homeowners
Across Southern California
Custom Spaces.
Built to Belong.
Thoughtful design. Lasting craftsmanship.
SE Builders designs and constructs detached ADUs, attached additions, and garage conversions for homeowners across Southern California — managing feasibility, permitting, construction, and final inspection under one accountable team.
Custom ADUs designed and built to add livable space and lasting value to your property.
Full-service
Feasibility through final inspection
Detached, attached & garage conversion ADUs
Permit-ready design packages
Serving LA, Orange, Riverside, San Bernardino & Ventura counties
SE Builders designs and constructs detached ADUs, attached additions, and garage conversions for homeowners across Southern California — managing feasibility, permitting, construction, and final inspection under one accountable team.
Spaces We Build for Better Living
Detached ADUs
Standalone backyard living spaces built for family, guests, rental use, or flexible property needs.
Garage Conversions
Convert an existing garage into a livable, code-conscious space with proper utilities, finishes, and layout.
Attached ADUs
Additional living space connected to the main home while maintaining comfort, function, and privacy.
Guest Suites
Comfortable private spaces for family members, visitors, or multigenerational living.
Home Office & Flex Spaces
Functional spaces designed for remote work, creative use, hobbies, or everyday flexibility.
Outdoor Living Upgrades
Accessory structures and exterior improvements that make the property more usable and connected.
A Clear Path From Idea to Move-In
We keep your ADU project organized and predictable, coordinating every phase so you always know what comes next.
Built for Southern California
Locally experienced. Detail-focused. Built to last.
Project Goals & Plan Review
We review your goals, site conditions, and vision to determine feasibility and shape a plan that fits your property.
Pre-Construction Coordination
We prepare permit-ready design packages and handle permitting so your project starts on solid footing.
Quality Construction Execution
Our team builds your ADU to California code with careful attention to structure, finishes, and craftsmanship.
Final Details & Project Completion
We complete final details, coordinate inspections, and hand over a finished, move-in-ready space.
Quality & Long-Term Value
An ADU is one of the most impactful ways to add value and livable space to a California property. We build with precision so your investment holds up and serves your family or tenants for years to come.
Ready to Add Space and Value With an ADU?
Let's talk about your property and goals. SE Builders will help you plan a custom ADU or garage conversion built for the way you live.
Get a QuoteFAQ
Frequently Asked Questions
SE Builders builds detached ADUs, attached ADUs, garage conversions, guest suites, home office and flex spaces, and outdoor living upgrades for homeowners across Southern California.
SE Builders serves ADU construction and garage conversion projects across Southern California, including Los Angeles, Orange, Riverside, San Bernardino, and Ventura counties.
Timelines vary based on scope, size, permitting, and site conditions. Our team reviews your specific project and plans to provide a realistic schedule before construction begins.
Yes. We handle everything from feasibility and permit-ready design packages through construction and final inspection, including multi-unit ADU developments.
Still have questions?
Talk to Our TeamWant to Know More About Our Services?
Explore other SE Builders services built for Southern California businesses.
Veterinary Construction
Specialized construction for veterinary clinics, animal hospitals, and pet-care facilities.
Learn More2Healthcare & Medical Construction
Clinics, medical offices, and urgent care builds with expert exam room and equipment planning.
Learn More3Operating Room Construction
Medical-grade operating rooms, procedure rooms, and sterile processing build-outs.
Learn MoreOur Work
Look at Some of Our ADU Construction Projects
Loma Custom Accessory Dwelling Unit (ADU)
Accessory Dwelling Units (ADUs)
Click to View This Amazing Project
Monrovia Multi-Unit ADU Conversion
Accessory Dwelling Units (ADUs)
Click to View This Amazing Project
Fullerton Custom Accessory Dwelling Unit (ADU)
Accessory Dwelling Units (ADUs)
Click to View This Amazing Project
Lerona Custom ADU Renovation
Accessory Dwelling Units (ADUs)
Click to View This Amazing ProjectService Areas
We Also Serve These Areas
Los Angeles County
Alhambra, Arcadia, Atwood, Avalon, Azusa, Bellflower, Beverly Hills, Burbank, Calabasas, Carson, Cerritos, Claremont, Commerce, Compton, Covina, Culver City, Downey, Duarte, East Los Angeles, El Monte, El Segundo, Gardena, Glendale, Glendora, Hawthorne, Huntington Park, Inglewood, La Mirada, La Puente, Lakewood, Lancaster, Long Beach, Los Angeles, Malibu, Manhattan Beach, Marina Del Rey, Montebello, Monterey Park, Norwalk, Palmdale, Pasadena, Pico Rivera, Rancho Palos Verdes, Redondo Beach, San Dimas, San Gabriel, Santa Clarita, Santa Fe Springs, Santa Monica, South Gate, Torrance, West Covina, West Hollywood, Whittier
Orange County
Aliso Viejo, Anaheim, Brea, Buena Park, Costa Mesa, Cypress, Dana Point, Fountain Valley, Fullerton, Garden Grove, Huntington Beach, Irvine, La Habra, La Palma, Ladera Ranch, Laguna Beach, Laguna Hills, Laguna Niguel, Lake Forest, Los Alamitos, Mission Viejo, Newport Beach, Orange, Placentia, Rancho Santa Margarita, San Clemente, San Juan Capistrano, Santa Ana, Seal Beach, Stanton, Tustin, Villa Park, Westminster, Yorba Linda
Riverside County
Banning, Beaumont, Blythe, Cathedral City, Coachella, Corona, Desert Hot Springs, Eastvale, Hemet, Indio, Jurupa Valley, La Quinta, Lake Elsinore, Menifee, Moreno Valley, Murrieta, Norco, Palm Desert, Palm Springs, Perris, Rancho Mirage, Riverside, San Jacinto, Temecula, Wildomar
San Bernardino County
Adelanto, Apple Valley, Barstow, Big Bear Lake, Chino, Chino Hills, Colton, Crestline, Fontana, Hesperia, Highland, Joshua Tree, Lake Arrowhead, Loma Linda, Montclair, Ontario, Rancho Cucamonga, Redlands, Rialto, San Bernardino, Twentynine Palms, Upland, Victorville, Yucaipa, Yucca Valley
Ventura County
Camarillo, Fillmore, Moorpark, Oak Park, Oak View, Ojai, Oxnard, Piru, Port Hueneme, Santa Paula, Saticoy, Simi Valley, Somis, Thousand Oaks, Ventura