Custom ADU Construction in California
Build an Accessory Dwelling Unit for rental income, guest space, or multigenerational living.
SERVICES
Accessory Dwelling Units
We specialize in designing and building Accessory Dwelling Units (ADUs) that add value, flexibility, and income potential to your property. From detached backyard homes to garage conversions and above-garage apartments, we handle permits, architectural design, utility connections, construction, and finishes. Our ADUs are perfect for rental income, in-law suites, or extended family living, built to meet California’s housing codes and energy standards.
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Projects
Explore Our Favorite Remodeling Projects
Modern Framing & Electrical Work
We provide expert structural framing and electrical installation for both residential and commercial projects. Our framing work ensures code-compliant structural integrity, whether for additions, remodels, or new…
Modern Backyard & Patio...
We design and build stunning outdoor living spaces perfect for entertaining or relaxing. Our services include custom patios, paver or concrete surfaces, pergolas, outdoor kitchens, fire pits, fencing, and…
Modern Flooring Installation (Tile...
We offer professional flooring installation with a wide selection of materials to suit your style and budget. Whether you’re upgrading to elegant hardwood, durable tile, or low-maintenance laminate or vinyl…
Modern Accessory Dwelling Units...
We specialize in designing and building Accessory Dwelling Units (ADUs) that add value, flexibility, and income potential to your property. From detached backyard homes to garage conversions and above-garage…
Modern Outdoor Living
Custom patios, pergolas, and backyard upgrades to enhance your space.
Modern Bathroom Remodeling
We create custom-designed bathrooms that combine comfort, function, and luxury. Our remodeling services include walk-in showers with frameless glass, modern soaking tubs, water-saving toilets, double…
Modern Kitchen Remodels
We specialize in transforming outdated kitchens into stunning, functional spaces that reflect your personal style and cooking needs. Our services include full demolition and redesign, custom cabinetry…
Modern Garage Remodels
We transform garages into clean, organized, and functional spaces—ideal for home gyms, workshops, offices, or additional storage. Our remodels include insulation, drywall, built-in shelving, flooring upgrades…
PROMISES
Ready to Start Your Next Project?
Whether you’re dreaming of a modern kitchen, a luxurious bathroom, or a full home makeover — we’re here to bring your vision to life. Let’s build something amazing together.
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Ready to Transform Your Home Into Something Amazing?
Stop dreaming and start living in the home you’ve always wanted. Call Serna Builders today or request your free consultation – your dream home is just one conversation away.
Urgent Construction or Remodeling Need?
From kitchen and bathroom remodels to garage conversions and electrical work — we’ve got you covered.
Free Remodeling Consultation
Frequently Asked Questions
How much does an ADU cost to build in California?
Cost varies significantly by ADU type detached, attached, or garage-conversion plus size, finishes, and site conditions. We provide a detailed, itemized quote after a site evaluation.
What types of ADUs do you build?
We build detached backyard homes, garage conversions, and above-garage ADUs designed to add value, flexibility, and rental income potential to your property.
Do I need a permit to build an ADU in California?
Yes, ADUs require permits and must meet California and local building codes. We manage the entire permitting process on your behalf.
Can an ADU be used as a rental property?
Yes, many homeowners build ADUs specifically to generate rental income or house family members.
How long does it take to build an ADU?
Timelines depend on ADU type and size, plus permitting timelines, which vary by city. We provide a realistic schedule during your free consultation.