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 Los Angeles
Hiring a home addition contractor in Los Angeles usually costs between $180 and $420 per square foot, with a 400-square-foot room addition running roughly $72,000 to $168,000. That’s the range families should plan around before they make the first call. Seedling ADU Los Angeles serves the entire city, from South Gate to Marina del Rey, with written pricing before any work starts and a crew that treats your house like it’s our own. Call Ben Ortega’s team at (213) 449-7136 for a free estimate. We’ll walk you through what’s possible on your lot, in your zone, with your budget.
Why Seedling ADU Los Angeles Is Los Angeles’s Preferred Home Addition Contractor Company
Los Angeles homeowners don’t need another contractor who disappears after the deposit. They need someone who understands how a 1930s bungalow in Highland Park differs from a 1960s ranch in South Pasadena. Our crews work across Los Angeles every week, and we’ve seen what opening up these older homes actually turns up: outdated wiring, undersized framing, failed waterproofing. That’s why we start with an inspection and put the real numbers in writing before a single tool is picked up.
Every Seedling project is backed by the 365-Day Done Right Promise. If something isn’t done right, we make it right, in writing, for a full year after completion. Our technicians are background-checked and uniformed. Families in Los Angeles know exactly who’s walking through their door. And the Cedarwell Care Promise applies on every visit: shoe covers and drop cloths inside the home, pet-safe products where there’s a choice, a photo of the clean-up before the crew leaves. Ben Ortega leads the Los Angeles team, and he’s the one who signs off on your written price before work begins. No surprises added after crews arrive.
Second Story Addition Contractor in Los Angeles
Second story additions in Los Angeles are one of the smartest ways to gain space when the lot won’t grow. Los Angeles lots are famously tight, and for many homeowners, going up is the only way to add bedrooms without giving up a yard. A second-story addition in Los Angeles typically costs between $250 and $450 per square foot, which includes structural reinforcement, seismic retrofitting, stairs, and roofing. That’s $125,000 to $400,000 for most 500- to 900-square-foot additions, depending on whether you’re adding a master suite or two bedrooms with a bathroom.
The catch is what’s hiding in the walls. In Mount Washington, we opened up a 1940s bungalow for a second-story addition and found knob-and-tube wiring, undersized 2×4 rafters, and failed stucco waterproofing. Our inspection-first process priced the electrical upgrade, structural reinforcement, and rainscreen retrofit into the contract before we touched a wall, and the hillside foundation retrofits were approved in writing after seismic review. That’s the difference between a quote that holds and a project that spirals.
Seismic and Foundation Work
Hillside lots in Los Angeles bring a second layer of engineering. If your home sits on a slope in Mount Washington, Echo Park, or Silver Lake, expect a soils report and possibly caissons or retaining work before the framing starts. We price this after the soils report comes back, not after the crew is already there.
Living at Home During Construction
Many Los Angeles families stay in the house while the second story goes on. That means framing dust, noise, and a crew on site for months. We keep the worksite sealed off from living areas, use quiet tools near bedrooms when kids are napping, and clean up every afternoon. The crew doesn’t leave until the drop cloths are up and the floors are swept.
Garage Addition Contractors in Los Angeles
Garage additions in Los Angeles run between $150 and $300 per square foot, so converting a two-car garage into a living space typically lands between $60,000 and $120,000 before finishes. Building new attached garage space costs more, generally $200 to $350 per square foot. The number moves based on whether the existing slab can be reused, whether the garage has power, and whether the walls need seismic shear upgrades.
And here’s what makes Los Angeles truly different: the granny flat loophole. In many R1 zones across Los Angeles, you can build an ADU above a garage even if the garage is non-conforming, as long as it doesn’t increase the footprint. In Silver Lake and Highland Park, where garages sit right on the lot line, this quirk lets homeowners add a second-story garage apartment without the usual setback variances. Most builders assume a non-conforming garage has to be demolished. We read the code first.
Garage-Top ADU Feasibility
Before you assume your garage can’t support a second story, let us look at the lot lines and the zoning. Our team has navigated garage-top additions in Silver Lake, Highland Park, and across the R1 hillside zones. What looks impossible at first glance is often a straightforward permitted build.
What an Older Garage Needs
Garages from the 1940s and 1950s in Los Angeles rarely have enough lateral strength for a second story. Expect shear wall installation, hold-downs, and sometimes new footings. We write every one of those items into the contract, priced as allowances, so you’re not guessing what the inspector will require.
Trusted Brands We Service in Los Angeles
Seedling ADU Los Angeles works directly with the brands serious ADU buyers research before calling anyone. We’re hands-on with Abodu, Cover, and Dvele, along with James Hardie siding and trim materials. For Los Angeles homeowners, that means prefab ADU panels and factory-built modules arrive on schedule, not on a contractor’s whim. And because our crews install these systems regularly across Los Angeles, we stock the common components and know which James Hardie profiles meet the wildfire-zone requirements in places like the Verdugo foothills and the Santa Monica Mountains interface.
Common Home Addition Contractor Problems We See in Los Angeles Homes
- Knob-and-tube wiring behind plaster walls. Pre-1980 Los Angeles homes frequently still carry active knob-and-tube circuits. Opening a wall for an addition triggers a full panel inspection, and usually a rewire. Without a written contingency, this can add $15,000 to $30,000 you didn’t plan for.
- Hillside lot drainage and retaining walls. Los Angeles hillside homes, especially in Mount Washington and parts of Echo Park, were built before modern drainage codes. Exposing the foundation often means adding a retaining wall or a new drainage system before the inspector signs off.
- Wildfire-zone material restrictions. Homes in the Very High Fire Hazard Severity Zone cannot use combustible siding or open-eave decking. If your addition sits in the urban-wildland interface, plan for ignition-resistant products and possible defensible-space changes to the yard.
- Non-conforming garage surprises. Many Los Angeles garages sit on lot lines or in setback violations. State ADU law often protects these structures, but only if the design doesn’t increase the footprint. We check this before you spend money on plans.
Pricing for Home Addition Contractor in Los Angeles, CA
Here’s what Los Angeles families actually pay. A bump-out addition of 150 to 250 square feet typically runs $45,000 to $95,000. A full room addition of 300 to 500 square feet lands between $72,000 and $210,000. Second-story additions start around $125,000 and can exceed $400,000 for a large master suite. Sunroom additions run $35,000 to $90,000 depending on glazing and foundation work. Bathroom additions usually fall between $40,000 and $85,000 in Los Angeles, where tiled showers and freestanding tubs are the norm.
What moves the price most: whether walls open into knob-and-tube wiring, whether the foundation needs seismic shear work, and whether the lot sits in a fire-hazard zone. Our written price includes line-item allowances for these unknowns. If a surprise appears, you approve the change in writing before we touch it. Call (213) 449-7136 for an exact quote. The estimate is free.
We Also Serve Cities Near Los Angeles
Our crews work across Los Angeles and the surrounding area, including South Gate, El Segundo, South Pasadena, and Marina del Rey. If you’re outside the city center, we can still help. Just check with our Home Addition Contractor in Los Angeles team when you call, and we’ll confirm scheduling for your neighborhood. Dispatch and scheduling are coordinated from our Los Angeles office, and our local crews serve all of these areas regularly.
Serving Los Angeles, CA - Our Local Coverage Area
We’re based in the Los Angeles 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 Los Angeles
In many R1 zones, Los Angeles allows an ADU above a garage even if the garage is non-conforming on setbacks, as long as the new structure doesn’t increase the footprint. That means if your garage sits too close to the lot line, you can often still build upward without a variance, which is why garage-top ADUs are so common in Silver Lake and Highland Park. Call (213) 449-7136 and we’ll check your specific lot and zone. These determinations are free.
Expect a mandatory electrical panel and wiring review, seismic bracing and shear wall requirements, and usually a full smoke and carbon monoxide detector upgrade. In pre-1980 homes, knob-and-tube wiring often must be replaced once exposed. Our inspection-first process identifies these triggers before we write the contract, and each one is priced as an allowance so you approve it in writing before we proceed.
Yes. Hillside lots, especially in neighborhoods like Mount Washington, Echo Park, and the Santa Monica Mountains, typically require a soils report, possibly caissons or grade beams, and frequently new retaining walls or drainage. These are not optional upgrades; they are code requirements triggered by the slope. We price them after the soils report comes back, not after the crew has already opened the foundation. Call (213) 449-7136 to walk through your specific lot.
If your home sits in a Very High Fire Hazard Severity Zone, the Los Angeles Fire Department will require ignition-resistant siding, enclosed eaves, and possibly tempered glass and ember-resistant vents. James Hardie fiber cement siding is one of the products we install regularly because it meets these requirements without sacrificing the look Los Angeles homeowners want. We verify your zone before we spec materials, so you’re not replacing siding halfway through inspection.
An allowance is a specific dollar amount written into your contract for known unknowns: knob-and-tube rewire, seismic shear upgrades, dry rot repair, foundation surprises, or upgrading a panel. What’s on the allowance list comes directly from our inspection. If we don’t use the full amount, you don’t pay the full amount. If an inspector requires something outside the allowance, you see the price and approve it in writing before work continues. Call (213) 449-7136 for a free estimate and a written price that accounts for what’s really inside your walls.
Written by Ben Ortega, Owner at Seedling ADU Los Angeles, serving Los Angeles and surrounding communities. For more on what a home addition involves, read our Home Addition Contractor guide, or call Ben’s team directly at (213) 449-7136.
