A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Garage Conversion Contractor Across South Whittier
A garage conversion in South Whittier typically runs $85,000 to $165,000 for a full ADU with kitchen and bath, and $45,000 to $85,000 for a simpler living-space conversion without plumbing. Most projects take 14 to 22 weeks from first measurements to final inspection, depending on whether LA County Fire Plan Check applies to your lot. Our Garage Conversion Contractor team has converted garages throughout unincorporated South Whittier, from the 90604 and 90605 ZIP codes down to the neighborhoods off Leffingwell Road. If you’re weighing an attached garage conversion against a detached structure, call (361) 315-4177 and we’ll walk you through what makes sense on your specific parcel.
We know the difference between what the City of Whittier requires and what LA County Public Works actually enforces on South Whittier lots. That distinction alone has saved our clients months of permit back-and-forth. Reed Calloway leads our estimating and project scoping, and he’s the one who will put your price in writing before any work starts.
Why Fielding ADU Builders Is South Whittier’s Preferred Garage Conversion Contractor Company
Most South Whittier homeowners calling us have already talked to someone who gave them a low number over the phone, then changed it once demo started. That’s the exact behavior The Garrison Code exists to prevent. Show up in the window. Price in writing. By the book. Leave it clean. Stand behind it for a year. We operate inside the Garrison Partners family, which has been building to this standard since 2006, and every project we take on in South Whittier follows it.
Our crews show up in uniform, background-checked before they ever step on your property. You’ll know who is on site every morning. The 365-Day Done Right Promise backs every garage conversion we build in South Whittier: if workmanship fails within one year, we return and correct it at no charge. That’s not a verbal promise. It’s written into your contract.
We also answer the phone. A live person picks up at (361) 315-4177, whether you call at noon or midnight. You won’t get a voicemail or a callback queue when you’re trying to schedule a site visit near Santa Gertrudes Avenue or off Imperial Highway.
Garage Conversion ADU in South Whittier
A Garage Conversion ADU in South Whittier means converting your existing garage shell into a fully permitted accessory dwelling unit with its own kitchen, bath, and separate entrance. Unincorporated South Whittier sits under LA County’s ADU rules, not the City of Whittier’s, which changes what gets reviewed, how long it takes, and what triggers a County Fire Plan Check. Most attached garage ADUs here run $95,000 to $165,000 complete. Detached conversions usually land $15,000 to $25,000 higher because of fire-rated wall requirements when the structure sits within five feet of a rear property line.
Attached Garage Conversion
An attached garage shares a wall with the house and usually has the main electrical panel nearby, which keeps service-upgrade costs down. South Whittier has thousands of 1950s and 1960s tract homes where attached garages were built on thin slabs with no vapor barrier. We trench for plumbing, pour a new subfloor, and frame inside the existing stem wall rather than trying to make the old slab work.
Detached Garage Conversion
A detached garage on a separate pad gives you more privacy as an ADU but triggers stricter fire separation. On rural-feeling South Whittier parcels where the structure sits within five feet of the property line, LA County Fire Plan Check applies. We’ve seen this catch contractors who quote a Whittier-city permit path and then stall for six weeks when the county kicks the plan back. We scope it from day one.
Garage Apartment Conversion in South Whittier
A Garage Apartment Conversion in South Whittier converts existing garage square footage into living space that functions as a full apartment: bedroom, living area, kitchenette or full kitchen, and a bath. For homeowners who don’t need a separate utility meter or want to keep the unit for family rather than tenants, this route typically runs $55,000 to $110,000. The range is wide because some South Whittier garages already have subpanels and sewer lines in the right place, and some need a full trench from the house across the yard.
Garage to Bedroom
Converting a garage to a bedroom only, without plumbing, is the lowest-cost path at $45,000 to $70,000. The work focuses on insulation, drywall, electrical, egress windows, and flooring. LA County still requires permits, and the window egress rule applies everywhere in South Whittier: a bedroom needs a window large enough to exit through in a fire. Older garages without side windows will need one cut into the wall.
Garage to Living Space
This is a flexible middle option: finished, conditioned space without a full kitchen. Think home office, gym, playroom, or guest suite with a half bath. In South Whittier, a garage-to-living-space conversion typically runs $50,000 to $90,000. The controlled variable is whether you tap into the existing house HVAC or run a separate mini-split, which most South Whittier homeowners choose given how hot uninsulated garages get in August.
Trusted Brands We Service in South Whittier
We regularly build with Cover and Boxabl systems for South Whittier homeowners who want prefab speed, and with conventional James Hardie siding when the goal is to match the existing house. Dvele and Mighty Buildings come up on larger ADU projects where the budget supports a more finished modular shell. We stock the fasteners, flashing, and trim profiles most common to mid-century stucco homes across the 90604 and 90605 ZIP codes, which keeps material runs short and keeps your schedule from slipping while a warehouse somewhere backorders a part.
Common Garage Conversion Contractor Problems We See in South Whittier Homes
- LA County Fire Plan Check missed on the quote. Detached garage conversions near a rear property line need a fire-rated wall and sometimes a residential sprinkler review. A contractor who quotes the City of Whittier path skips this, and the permit stalls mid-build.
- A thin 1950s slab that can’t carry finished floor load. Most South Whittier garages were poured as parking pads, not living space. Once demo reveals a 3-inch unreinforced slab, you need trenching for plumbing and a new subfloor, which moves the price.
- Existing panel is too small for an ADU’s kitchen and mini-split. Many South Whittier homes still run 100-amp service. Adding a full kitchen plus HVAC to a garage ADU often forces a 200-amp upgrade, and that’s a five-figure line item if it wasn’t scoped upfront.
- Setback variance required on tight rear-lot parcels. Some South Whittier lots are long and narrow, and a detached garage already sits close to a side or rear line. LA County may require a setback variance with written justification and neighbor notice before conversion starts.
Pricing for Garage Conversion Contractor in South Whittier, CA
Here are honest ranges for South Whittier’s market, before permit fees. A basic garage-to-bedroom conversion runs $45,000 to $70,000. A garage-to-living-space with half bath runs $50,000 to $90,000. A full attached garage ADU with kitchen and bath runs $95,000 to $165,000. A detached garage ADU with fire-rated wall and separate utilities runs $110,000 to $180,000. The price moves on five things: slab condition, electrical service size, sewer line distance, fire separation requirements, and whether you choose prefab or conventional framing. We put the price in writing before any work starts, and the number you approve on day one is the number on the final invoice. Call (361) 315-4177 for a free, written estimate.
We Also Serve Cities Near South Whittier
Fielding ADU Builders serves South Whittier and the surrounding metro, including Los Angeles, Long Beach, Anaheim, and Riverside. If you’re in a neighboring city and want the same Garrison Standard approach, our Garage Conversion Contractor team can scope your project the same way we do here: in person, with a written price, before anything starts.
Serving South Whittier, CA - Our Local Coverage Area
We’re based in the South Whittier area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Garage Conversion Contractor in South Whittier
South Whittier is unincorporated, so LA County Public Works is your permitting authority, not the City of Whittier. You’ll file through LA County, and if your detached garage sits near a rear property line, LA County Fire Plan Check applies. Call (361) 315-4177 and we’ll confirm your parcel’s exact path before you spend anything.
Usually not. Most South Whittier garages were built in the 1950s and 1960s on 3 to 4 inches of unreinforced concrete meant for parking. A finished ADU needs plumbing trenches and a load-rated subfloor. Budget for slab demo and a new subfloor unless we confirm otherwise on site.
Three things move the price mid-project: a thin slab that needs full replacement, an electrical panel that can’t feed the new load and requires a service upgrade, and fire-separation requirements discovered during plan review. We scope all three during the first site visit so your written price already accounts for them. That’s the whole point of pricing in writing.
Plan for 14 to 22 weeks total. LA County plan review on an ADU typically runs four to eight weeks, County Fire adds two to four more when it applies, and construction runs eight to twelve weeks. Projects that skip fire plan check on the front end end up longer, not shorter.
Prefab makes the most sense on detached garage conversions where the shell can be replaced or wrapped quickly and the budget supports the platform cost. For attached conversions on tight South Whittier lots, conventional framing inside the existing garage usually costs less and matches the house better. We work with Cover, Boxabl, Dvele, and Mighty Buildings and will tell you honestly which route fits your parcel and budget.
Call (361) 315-4177 to schedule your free estimate. Reed Calloway will walk your South Whittier lot, check the slab, the panel, and the property line, and hand you a written price before any work begins.
Written by Reed Calloway, Owner at Fielding ADU Builders, serving South Whittier and the surrounding Los Angeles metro.
