







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Long Beach
A home addition in Long Beach costs between $180 and $420 per square foot depending on scope, finishes, and whether your lot triggers coastal corrosion or seismic retrofit requirements. Most room additions in neighborhoods like Wrigley, Bixby Knolls, and Los Altos run $95,000 to $280,000 for a completed project, including design, permits, and finish work. We coordinate scheduling and dispatch from our Los Angeles office, and our crews serve Long Beach neighborhoods directly every week. If you’re planning a second story, a garage addition, or a bump-out and want a written price before any work starts, call (562) 362-4592.

We know Long Beach lots. We know the alleys in Wrigley where a detached garage can become a rentable unit with its own address. We know the marine air in Belmont Shore that eats standard fasteners in five years. This page tells you what actually matters here, what it costs, and what we specify so the addition lasts.
Why Seedling ADU Long Beach Is Long Beach’s Preferred Home Addition Contractor Company

We’re not the loudest contractor in Long Beach. We’re the one that shows up with a written scope, a fixed price, and a crew in uniform who puts shoe covers on before stepping onto your hardwood. Ben Ortega leads our Long Beach projects, and every job we build carries the 365-Day Done Right Promise in writing. If something isn’t done right, we make it right. No phone tag, no arguing about whose fault it is.
The Cedarwell Care Promise applies to every Long Beach project we build. Drop cloths inside the home. Pet-safe products where there’s a choice. A photo of the clean-up before the crew leaves each day. Those aren’t add-ons; they’re written into how we operate. When you have an active build, a live person answers our phone 24/7. No voicemail trees. No next-business-day callbacks. That matters when you’re a family with kids and a dog and you have questions at 7 p.m.
Long Beach is one of our core service areas, and our crews know the local permit office, the coastal zone rules, and the retrofitting requirements for older garages that apply in Alamitos Beach, Belmont Heights, and along Ocean Boulevard. We don’t fly crews in from another county. We plan around school drop-off times, nap schedules, and the fact that your neighbor’s driveway is eight feet from your property line.
Second Story Addition Contractor in Long Beach
A second story addition in Long Beach typically runs $140,000 to $320,000, with the wide range driven by whether the existing foundation and first-floor walls can carry the load or need seismic work first. Homes built between the 1920s and 1940s in Bixby Knolls and California Heights often need soft-story retrofitting before we can frame upward. That’s not a surprise charge we spring on you. It’s in the written price from day one.
Salt air changes the hardware equation. Standard galvanized Simpson Strong-Tie connectors on a second-story addition in Belmont Shore rust to red dust within five years. We specify hot-dip galvanized or 316 stainless connectors on every coastal Long Beach project. The material cost difference runs $2,000 to $4,500 on a typical addition. Replacing failed connectors after the fact costs ten times that.
Foundation and Seismic Review
Before we frame a second story in Long Beach, we check the existing foundation, the sill plate condition, and the lateral wall bracing. Many 1920s craftsman bungalows in Wrigley and Rose Park were built with unreinforced masonry or minimal cripple wall bracing. A proper retrofit adds 15 to 25 percent to the total project cost, but it’s the difference between an addition that stays level and one that shifts after the next moderate quake.
Roofing and Exterior Hardware
Roof fasteners on Long Beach additions need to be hot-dip galvanized or stainless. We re-roofed a garage-to-ADU conversion in Alamitos Beach where the original galvanized roof fasteners had rusted through in under six years from salt spray. We replaced them with hot-dip galvanized ring-shank nails, switched the window frames to marine-grade 316 stainless, and sealed the paver joints with polymeric sand to stop chloride creep.
Garage Addition Contractors in Long Beach
A garage addition in Long Beach runs $60,000 to $180,000 when converted into an ADU, or $40,000 to $95,000 for a simple garage expansion attached to the existing home. The Wrigley district changes the math entirely: those 1920s-platted alleys let homeowners convert detached garages into ADUs with their own street address, avoiding front-yard driveway cuts entirely. That pattern is impossible in neighboring Lakewood or Signal Hill, where alley access was never platted.
Detached garages in Belmont Shore and Alamitos Beach often sit on old slabs with minimal footing depth. If we’re converting one into living space, the slab gets evaluated for moisture intrusion and seismic anchoring. Some need a full new foundation; others need perimeter pinning and a vapor barrier. Either way, the price is written before we start.
Alley-Loaded ADU Conversions
In Wrigley, the long narrow detached garage that opens to the alley is the single best ADU candidate in Long Beach. It gets a separate address, its own entrance, and no driveway cut across the front yard. We’ve built these from Tuff Shed shells and from custom on-site framing. The alley-fronting window and door choices get marine-grade finish because salt film accumulates in the tracks and jams standard vinyl frames within two or three seasons.

Attached Garage Expansions
When you expand an attached garage for more storage, a workshop, or a ground-floor suite, the tie-in to the existing roofline and drainage matters more than the square footage. Long Beach’s flat and low-slope roofs need proper crickets and scupper design because marine humidity encourages staining where water ponds. We use James Hardie trim and siding on these additions because it holds paint longer in coastal air than raw wood or standard fiber cement products.
Trusted Brands We Service in Long Beach
We work with the brands serious Long Beach buyers research before calling anyone. Abodu and Cover make prefab ADU units that work well on the wider lots in Bixby Knolls and Los Altos, and we handle the site work, foundation, utility connections, and finish details. James Hardie lap siding and trim are our default exterior for coastal exposure because they resist moisture swell and hold paint longer than wood. For a detached garage shell or a workshop addition, a Tuff Shed structure with our foundation and finish work is often the most economical path. We stock local parts and common hardware for Long Beach jobs so a supply delay never stalls a build.
Common Home Addition Contractor Problems We See in Long Beach Homes
- Rusted connectors on coastal second-story additions. Standard galvanized Simpson Strong-Tie connectors in Belmont Shore and Peninsula neighborhoods fail to red dust within five years. We specify hot-dip galvanized or 316 stainless for every structural tie on a Long Beach addition.
- Jammed window frames from salt film. Inland-grade vinyl window frames on alley-facing garage conversions collect salt film in the tracks until they bind. Marine-grade 316 stainless frames and hardware solve this before it starts.
- Efflorescing paver joints on coastal patios. Salt-laden moisture wicks up through unsealed paver joints and leaves white crust on the surface within two seasons. Polymeric sand sealed joints stop the chloride creep.
- Soft-story seismic issues on pre-1978 garages. Long Beach’s dense coastal neighborhoods have thousands of unreinforced masonry or soft-story garages. Adding a second story above one without a retrofit is a liability, not a savings.
Pricing for Home Addition Contractor in Long Beach, CA
Here are the ranges you’ll hear from reputable contractors in Long Beach for 2026 builds. A room addition runs $95,000 to $210,000. A second story addition runs $140,000 to $320,000. A garage ADU conversion runs $60,000 to $180,000 depending on whether you’re doing a prefab unit like Abodu or Cover, or full custom framing. A sunroom or bump-out runs $45,000 to $120,000. These numbers include design, permits, structural work, and finish materials. Coastal-spec hardware adds 3 to 7 percent to the structural budget. It is money well spent. Call (562) 362-4592 for a written line-item estimate, free, before you commit to anything.
The price gap between coastal-spec and inland-spec is real. Standard zinc-plated hardware and interior-grade window frames can save $6,000 to $9,000 on a typical Long Beach addition. Replacing rusted connectors, jammed windows, and effloresced pavers within a decade costs $25,000 to $40,000, and that’s before you count the disruption. We write the coastal-spec price the first time and you never pay the repair bill.
We Also Serve Cities Near Long Beach
Our crews work throughout Long Beach and the surrounding communities. We build in Signal Hill, Carson, Lakewood, and Cypress. If you’re comparing contractors across city lines, remember that the Home Addition Contractor team at Seedling ADU Long Beach writes one price for the whole job, regardless of which permit office we’re working with. Call us for details on serving your specific neighborhood.
Serving Long Beach, CA - Our Local Coverage Area
We’re based in the Long Beach 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 Home Addition Contractor in Long Beach
Alamitos Beach garages sit in a marine air exposure zone where standard galvanized hardware, inland-grade window frames, and unsealed paver joints fail within five to ten years. The coastal-spec materials we specify add $6,000 to $9,000 to a typical conversion. Lakewood’s inland location doesn’t require marine-grade finishes, which is why the same square footage is cheaper there. Call (562) 362-4592 for an exact quote, and we’ll show you the line items.
Yes, and that’s the advantage of the Wrigley alley pattern. The city of Long Beach can issue a separate address for an ADU that fronts an alley, which gives you a distinct mailing address, separate utility metering, and cleaner rental bookkeeping. Construction-wise, the alley-facing doors and windows need marine-grade finish, and we handle that in the written scope. We can walk you through the address application as part of the permit package.
We evaluate the existing foundation, sill plate, and lateral wall bracing before framing begins. On pre-1978 homes in Long Beach, adding a second story typically requires shear wall installation, foundation anchoring, and often a full soft-story retrofit of the garage below. This adds 15 to 25 percent to the total project cost, and it’s written into the price before we start, not after the walls are open. Call (562) 362-4592 and we’ll explain what your specific house needs.
Hot-dip galvanized ring-shank nails are the minimum for coastal Long Beach. On homes within a half mile of the water in Belmont Shore or the Peninsula, we specify 316 marine-grade stainless fasteners for everything exposed to salt air. The original galvanized fasteners we see on Alamitos Beach roofs rust through in under six years. A full re-roofing with the right fasteners adds $1,500 to $3,500 to a garage ADU conversion, and we include it in the written price.
Salt film accumulates in window tracks within two or three seasons on standard vinyl frames in coastal Long Beach. The tracks corrode, the sashes jam, and the frames start to discolor. Marine-grade 316 stainless frames and hardware eliminate the problem. The upgrade costs $800 to $2,200 per window depending on size, and it’s worth every dollar on an alley-facing ADU in Wrigley or Alamitos Beach. Call (562) 362-4592 for a free estimate with the right window spec included.
Planning a home addition in Long Beach means deciding between the coastal-spec build that lasts and the inland-spec build that rusts out in a decade. We write the coastal-spec price the first time, on paper, before any tool gets picked up. Ben Ortega and the Seedling ADU Long Beach crew would be glad to walk your property, measure your garage, check your alley access, and give you a line-item price you can actually plan around. Call (562) 362-4592 to schedule your free estimate.
Written by Ben Ortega, Owner at Seedling ADU Long Beach, building home additions, garage conversions, and ADUs in Long Beach, CA.









