Room Additions & ADU in Orange County-
Custom Home Expansions

A room addition expands your existing home by adding square footage—like a new bedroom, kitchen extension, or second story. An ADU (Accessory Dwelling Unit) is a separate, self-contained living space that can be detached or attached, often used for guests, rental income, or multigenerational living. USA Home Remodeling specializes in both, helping you choose the right solution for your property and goals.

es, both room additions and ADUs require city permits and zoning approvals. Our team handles the entire permitting process, ensuring your project meets all California building codes, city ordinances, and structural requirements. We manage the paperwork so you don’t have to.

Room additions in Southern California typically range from $200 to $400 per square foot, depending on design, materials, and complexity. ADUs generally start around $120,000–$250,000, depending on whether they are garage conversions, attached units, or detached new builds. We provide free estimates and 3D designs to help you plan your investment.

Most room additions and ADUs take between 10 to 16 weeks, not including design, permits, and construction. Larger or more complex projects may take longer. At USA Home Remodeling, we create a detailed project timeline and keep you informed every step of the way.

Absolutely. Every room addition and ADU we build is fully customized to your needs—whether it’s a master suite, home office, rental unit, or in-law suite. You’ll work with our design team to select layouts, finishes, and fixtures, and we’ll show you exactly what to expect with a realistic 3D rendering before construction begins.