ADU Company in Whittier, CA
Building an ADU in Whittier means dealing with something most Southern California cities never have to think about: the Whittier Fault. That single geological fact changes how we price, plan, and permit every accessory dwelling unit in this city. It also means Whittier homeowners need a builder who checks the fault-zone maps before promising a rear-yard unit will work. Call (254) 602-5618 to talk through your lot with someone who knows what Whittier actually requires.
Why Whittier Homes Are Different
Whittier’s housing stock is older than what you’ll find in Downey or Pico Rivera, and that age shows up in two ways on almost every ADU job. First, the post-WWII single-family homes that dominate neighborhoods like Michigan Park and East Whittier were built mostly between 1945 and 1970, which means 60-amp and 100-amp electrical panels are common. A detached garage conversion almost always requires a panel upgrade before the city will sign off. Second, the older blocks around Uptown Whittier hold 1920s and 1930s Craftsman bungalows and Spanish Colonial homes where the original foundation needs a structural assessment before we add square footage or a second unit.
Terrain splits the city. The Whittier Hills and Friendly Hills neighborhoods rise against the Puente Hills, and ADU projects there routinely need retaining walls, compaction reports, and erosion control that flat-lot jobs in the lower basin never trigger. That adds real money, not a rounding error. A hillside ADU in Friendly Hills can run 15 – 30% more on site preparation alone compared to the same unit on a flat East Whittier lot.
Then there’s the fault itself. The Whittier Fault cuts directly through the city, and portions of residential Whittier fall inside California’s Alquist-Priolo Earthquake Fault Zone. On an affected parcel, habitable space cannot sit within 50 feet of the fault trace without a site-specific geological investigation. That investigation costs thousands and can delay a project by months. Contractors who skip the LA County fault-zone lookup before pricing a Whittier ADU often discover mid-proposal that the obvious rear-yard pad is unusable, forcing a redesign to a front-of-lot position nobody wanted. We pull the county hazards map before we walk your property, not after we’ve quoted you a price.
Our Main Whittier Services
Whittier homeowners typically call us about one of three projects: adding living space to the main house, converting an existing garage into a rental or family unit, or building a standalone ADU from the ground up. Each has its own Whittier page with local pricing and build details.
Home Addition Contractor in Whittier
A home addition in Whittier usually means expanding a 1940s or 1950s single-family home on a lot that still has room to grow. On the older Craftsman blocks near Uptown, foundation work and matching rooflines drive the cost. In East Whittier, the job is more straightforward: frame out, tie into the existing roofline, upgrade the panel, and finish to match the original house. We handle the plans, the permits, and the build. Read the full breakdown on our Home Addition Contractor in Whittier page.
Garage Conversion Contractor in Whittier
Whittier’s deep lots and detached rear garages make the garage conversion one of the most common ADU paths in this city. Those one-car garages were built as storage for a single vehicle, not living space, so we address footing depth, insulation, and almost always a panel upgrade from the original 60-amp or 100-amp service. The payoff is a rentable unit without the foundation cost of a new build. Detailed pricing and process are on our Garage Conversion Contractor in Whittier page.
ADU Builders in Whittier
A standalone ADU in Whittier gives you a second front door on your lot, and with it a second address. On flat East Whittier lots, a standard one-bedroom unit goes in cleanly with a trench for new utilities and a small foundation. In the Whittier Hills, the same unit needs geotechnical work, drainage design, and possibly a retaining wall before framing starts. We build stick-framed and prefab units, including Abodu, Cover, Dvele, Mighty Buildings, and Boxabl, depending on access and budget. Start with our ADU Builders in Whittier page.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Whittier
We work with leading ADU brands and materials across Whittier, including our brands: Dvele, Mighty Buildings, and Boxabl for prefab units, plus James Hardie siding for stick-built additions. Our familiarity with each system means we match the right product to your lot, not the other way around.
Pricing for ADU Company in Whittier, CA
| Service | Typical range in Whittier |
|---|---|
| Detached ADU (1-bed, 400 – 600 sq ft) | $180,000 – $260,000 |
| Detached ADU (2-bed, 700 – 900 sq ft) | $260,000 – $380,000 |
| Prefab ADU (per sq ft, delivered & set) | $280 – $420 |
| Attached ADU (JADU, 300 – 500 sq ft) | $120,000 – $190,000 |
| Garage conversion (400 – 600 sq ft) | $110,000 – $165,000 |
| Garage conversion with panel upgrade | $125,000 – $185,000 |
| Home addition (400 – 600 sq ft) | $140,000 – $210,000 |
| Home addition (700 – 1,000 sq ft) | $210,000 – $340,000 |
| Site prep (sloped lot, retaining wall) | $15,000 – $45,000 |
| Electrical panel upgrade (100 – 200 amp) | $3,500 – $6,500 |
Hillside work in Friendly Hills or the Whittier Hills pushes the top of these ranges. Fault-zone geological studies, which flat-lot cities never require, can add $4,000 – $8,000 before construction begins. Every price we give is written before work starts, and it doesn’t change at the door.
Neighborhoods We Serve in Whittier
Our crews work throughout Whittier, from the flat post-WWII tracts to the hillside streets where drainage and foundations demand extra care. We know which neighborhoods face fault-zone restrictions and which ones typically don’t.
- East Whittier
- Michigan Park
- Friendly Hills
- Uptown Whittier
- The Whittier Hills
We can typically reach any Whittier neighborhood the same day for a site visit or estimate.
Service Area – Cities Near Whittier
Lodgewick ADU Builders also serves Pico Rivera, CA, South El Monte, CA, Hacienda Heights, CA, and Montebello, CA. If you’re in a neighboring city and considering an ADU, garage conversion, or home addition, the same written-price guarantee applies. Dispatch and scheduling run through our Los Angeles office, with crews serving Whittier locally.
Serving Whittier, CA - Our Local Coverage Area
We’re based in the 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 ADU Company in Whittier
Plan on 3 – 5 months for city plan check and permits, longer if your parcel sits inside the Alquist-Priolo fault zone and needs a geological study. Call (254) 602-5618 and we’ll check your parcel before you spend anything.
No. Only parcels inside the mapped Alquist-Priolo Earthquake Fault Zone face the 50-foot setback rule and possible geological study. We screen every Whittier lot before quoting, so you’ll know early whether it applies to yours.
We won’t start construction until HOA approval is in hand, if your Whittier neighborhood has one. We’ll help you prepare the submittal package, but no work begins until the board signs off.
Call (254) 602-5618 to schedule your free estimate, or visit our home to learn more about The Kingswell Guarantee.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Whittier Customers Say
"A whole backyard ADU from scratch. Terrified me going in, but they kept me updated weekly and there were no nasty surprises. Quality work and a fair price."
- Noreen Fletcher"Built a backyard unit for my mother in law. They handled the permits, gave me a real timeline, and stuck to it within a few days. The written price is what we paid, which anyone who's done construction knows is rare."
- Dennis Fairchild"Garage conversion into a studio for our teenager. Honest about what was realistic and what wasn't, finished close to schedule, and cleaned up the site daily."
- Marcus Beaumont