Home Additions & ADU in San Pedro - One Fixed Price, Permits Handled

Fast, Reliable Home Additions & ADU Across San Pedro

Most San Pedro homeowners don’t come to us because they’ve outgrown their house overnight. They come to us because the house that made sense in 1952 stopped making sense somewhere around the time the kids moved back in, or mom started needing a room on the ground floor, or the bluff-view lot finally seemed like it deserved more than 900 square feet. A room addition or ADU in this part of Los Angeles typically runs $45,000-$130,000 for groundwork-to-final-inspection work, and the permitting path is different here than almost anywhere else in the county. We know those differences because we build here. Call (877) 610-1318 when you’re ready to talk about what yours would take.

Call (877) 610-1318

Why Barrett & Sons Construction Is San Pedro’s Preferred Home Additions & ADU Company

Tom Barrett started this company in 1998 and never handed the job to a franchise manager. His sons run the crews, they carry the Barrett name on their shirts, and most days at least one of them is standing on a San Pedro lot looking at the same thing you’re looking at. That matters here because additions in San Pedro don’t follow a pattern you can download from a national playbook. Sloped lots, bluff-edge setbacks, Coastal Commission review, 1920s pier-and-beam foundations sitting under a marine layer that never quite dries out: this is day-to-day work for us, not an exception.

The reviews from San Pedro customers keep coming back to three things: the quote matched the bill, the permit inspector signed off without a fight, and someone answered the phone when they called. We answer live, 24/7. Tom publishes his name, address, and license number, so you can look him up before you ever sign. The L.O.C.A.L. code we work by isn’t marketing; it’s Local roots, On time, Community first, Accountable, Loyal. That’s the only way a company survives three decades in a place where your customers see you at the hardware store on Saturday.

Our Home Additions & ADU Services in San Pedro

ADU Design & Permitting

In San Pedro’s 90731 and 90732 zip codes, an ADU on a bluff-adjacent lot can trigger California Coastal Commission review in addition to standard LADBS permitting. Most out-of-town crews never see that coming until month three. We do, because we’ve shepherded those exact permit packages through the dual-agency process on plenty of San Pedro hillsides. We handle the design, the structural drawings, the Coastal Development Permit paperwork when it applies, and the inspections, so you get one point of contact from first sketch to final sign-off.

Garage Conversion ADU

Plenty of San Pedro’s older homes still have detached garages from the 1930s and 40s that were built for one car and a workbench, never for living use. Converting one into a rentable unit runs $30,000-$80,000 here, depending on whether the existing slab needs underfloor insulation, the electrical service can handle the added load, and whether we’re working around a pier-and-beam structure that’s been settling for 80 years. Our Home Additions & ADU team treats these not as quick flips but as permanent living space that has to pass a real inspection.

New Detached ADU

A ground-up detached ADU in San Pedro usually falls between $90,000 and $220,000, and the range is wide for a reason: some lots are flat and accessible, while others sit on a western bluff where we’re pouring a new foundation into hillside, engineering a retaining wall, and keeping everything clear of the coastal slope. We build them for extended family, for rental income, and increasingly for owners who want to age in place while a caregiver lives on-site. Either way, the drawings start with the dirt, not the floor plan.

Junior ADU & Interior Conversion

When the footprint can’t grow outward, the smartest San Pedro ADU is often already inside the house. A junior ADU carved from an existing bedroom, workshop, or oversized laundry room can run well under the cost of a detached build and still create a legal, lockable unit with its own entrance. These conversions move faster because they usually avoid the setback and slope issues that trigger Coastal Commission scrutiny, though we still pull permits and get inspections signed on every eligible job.

Trusted Brands We Service in San Pedro

We install materials you can look up, not mystery brands off a van. On exterior work around San Pedro, that often means Techo-Bloc or Cambridge Pavers for hardscape that has to hold up against salt air and constant damp. On foundations and site prep, we use Quikrete products that we source locally so San Pedro customers aren’t waiting on a freight order when weather finally clears. If you prefer a specific brand for your project, tell us; we’ll price it in writing and honor it.

Common Home Additions & ADU Problems We See in San Pedro Homes

• Foundations that predate port truck volume. Most San Pedro homes built between the 1920s and 1950s sit on piers or older concrete that was never engineered for thousands of daily truck movements on Gaffey Street and Harbor Boulevard. We find concealed settling and hairline cracks on almost every addition we open up, and we correct it before framing starts.
• Coastal Commission surprises. Bluff-adjacent work in 90731-90732 frequently gets flagged for CDP review on top of regular LADBS permitting. A contractor who doesn’t anticipate that dual-agency timeline at bid time is handing you a delay, not a schedule.
• Marine-layer moisture in walls. San Pedro’s heavier fog keeps exterior framing damp for months at a stretch, which accelerates wood rot and rust on exposed fasteners. We spec materials and detailing for this climate, not for a dry inland build that would pass in Torrance but fail here.
• Sloped-lot drainage conflicts. Western bluff lots often route runoff toward the foundation or into a neighbor’s retaining wall. Before we add square footage, we correct the drainage so the addition isn’t inheriting a water problem the original house already had.

Pricing for Home Additions & ADU in San Pedro, CA

We Also Serve Cities Near San Pedro

Our San Pedro crews work regularly in Lomita, Torrance, Rancho Palos Verdes, and Rolling Hills Estates. The permitting realities shift once you cross into the hills or toward the coast, so if you’re on the edge of our service area, call and ask. If we can help on a project like Kitchen Remodeling in San Pedro while we’re already on your lot, we’ll tell you honestly. And we handle Bathroom Remodeling in San Pedro with the same written-scope discipline on every job.

FAQs - Home Additions & ADU in San Pedro