ADU Company in Tustin - Design, Permits and Build Under One Contract

ADU Company in Tustin, CA

Fielding ADU Builders handles ADU construction, garage conversions, and room additions across Tustin, from the historic streets of Old Town to the ranch-home tracts that stretch toward the foothills. Tustin jobs are rarely one-size-fits-all: a 1960s slab-on-grade home with a Zinsco panel needs different work than a designated historic Craftsman, and we price both honestly before anything starts. Every project gets a written price up front and a one-year written guarantee under the Garrison Standard. Call (424) 577-4306 to schedule a free estimate.

Call (424) 577-4306

Why Tustin Homes Are Different

Tustin splits into two distinct housing realities, and that split drives how we plan every job. Old Town holds early-1900s Craftsman and Spanish Revival homes on irregular lots, many with designated historic status. An ADU there often has to match the existing architectural style, and setbacks can shrink what fits. Outside Old Town, the picture flips: single-story ranch homes built from the 1960s to 1980s sit on generous R-1 lots where detached ADUs make the most sense. Those older tract homes come with their own issues. We regularly find Zinsco or Federal Pacific electrical panels that have to go before a new unit can be fed, and cast-iron drain lines that are at the end of their life. Tustin’s inland Santa Ana Valley location means summer days past 90°F and dry Santa Ana winds, so Title 24 cool roofs and high-efficiency HVAC are not optional add-ons; they’re code. In hillside-adjacent and unincorporated areas like North Tustin and Lemon Heights, we work within the city’s WUI overlay and RA zoning, which changes material requirements and what the permit office will accept.

Our Main Tustin Services

Most Tustin homeowners call us about one of these three projects. Each has its own page with pricing and Tustin-specific detail.

Room Addition Contractor in Tustin

A room addition in Tustin usually means extending a slab-on-grade ranch home outward or converting underused interior space into a bedroom, office, or family room. Old Town additions often require design review, and we handle that paperwork before the first day of framing. We also check for the cast-iron drain lines and outdated panels common to 1960s-era homes, because adding square footage on top of failing infrastructure is a mistake. Room Addition Contractor in Tustin covers specific costs, timelines, and Tustin permit steps.

Garage Conversion Contractor in Tustin

Converting a garage in Tustin means turning an existing footprint into conditioned living space, which is usually the most cost-effective way to add a room without touching the lot line. Tustin garages from the 1970s and 1980s are often attached and built on the same slab as the house, but we still verify the slab thickness, the electrical service, and whether the garage was ever permitted as living space. Some older Tustin tracts carry private deed restrictions from that era that can block a garage conversion, and we check those before you spend a dollar. Garage Conversion Contractor in Tustin has the full breakdown.

ADU Builders in Tustin

Detached ADUs on Tustin’s larger R-1 lots are the fastest-growing project type we handle. We work with conventional stick-built construction using James Hardie siding, and we also build with prefab platforms like Abodu, Cover, and Dvele where the lot and budget line up. In areas of North Tustin and Lemon Heights zoned Residential Agriculture, state law allows one ADU and one JADU regardless of lot size, which opens up properties that older zoning would have excluded. ADU Builders in Tustin walks through the options and what each method costs here.

Brands We Service in Tustin

We build with the prefab and modular platforms Tustin homeowners ask about most, including Abodu, Cover, and Dvele, plus conventional builds with James Hardie siding. Fielding ADU Builders is part of the Garrison Partners family, founded in 2006, and every crew member is background-checked and uniformed. Our brands page lists the full lineup.

Pricing for ADU Company in Tustin, CA

Neighborhoods We Serve in Tustin

We work across the full span of Tustin, from the tight lots of Old Town to the wider parcels in the northern hills. Our crews are scheduled locally, and we typically start within two to three weeks of permit approval depending on the current queue.

• Old Town Tustin
• Tustin Ranch
• Columbus Square
• North Tustin / Lemon Heights (unincorporated RA and WUI zones)
• Tustin Legacy

Service Area – Cities Near Tustin

Beyond Tustin, we serve homeowners in neighboring Orange County cities, including Santa Ana, CA, Orange, CA, Newport Beach, CA, and Garden Grove, CA. Dispatch and scheduling are coordinated from our Los Angeles office; crews serve Tustin locally.