A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted Home Addition Contractor for Los Angeles Homeowners
A home addition in Los Angeles typically costs between $140 and $320 per square foot, with most projects landing between $90,000 and $350,000 depending on the type of room, foundation work, and finishes you choose. At Seedling ADU Los Angeles, we handle the part that keeps families up at night: a written price before any work begins, a crew that leaves your floors clean every single day, and a Home Addition Contractor Maintenance Checklist for Los Angeles Homeowners approach that means if something isn’t right, we make it right. Ben Ortega, who leads our Los Angeles team, has spent years walking homeowners through additions in neighborhoods from Mar Vista to Eagle Rock, and he’ll tell you the same thing every time: the construction is only half the job. The other half is knowing your kids can sleep through the day’s work and your dog won’t find a stray nail in the yard. Call (213) 449-7136 to talk through what you’re planning, and we’ll give you honest numbers before you commit to anything.
We’re part of the Cedarwell family of companies, and every project we take on follows the Cedarwell Care Promise: shoe covers and drop cloths inside your home, pet-safe products where there’s a choice, and a photo of the clean-up before the crew leaves for the day. That’s not an upsell. It’s just how we work. If you’re adding a home addition in Los Angeles, you’re already making a big enough decision. You don’t need to wonder whether the crew will respect your house while they’re in it.
Sunroom Addition
A sunroom addition in Los Angeles gives you a light-filled room that bridges your indoor space and your yard, and it typically runs $55,000 to $145,000 depending on size, glazing, and whether you extend the roofline or build a separate structure. Seedling ADU Los Angeles handles sunroom additions from the first structural review through final paint, with the same written price and clean-up standard we bring to every project. In neighborhoods like Los Feliz and Mar Vista, we see homeowners using sunrooms as morning rooms, plant rooms, and homework spaces, not just seasonal retreats. Los Angeles weather means a sunroom here is a year-round room, which changes how we think about insulation and roof connection details.
Foundation and Roof Tie-In
Most sunroom additions either extend an existing roofline or sit on a new foundation. We inspect the existing slab, check the roof pitch, and give you a written line-item price before any tear-off starts. No surprises after the crew shows up.
Glazing and Temperature Control
Los Angeles sun isn’t gentle in August. We walk you through low-E glass options, operable windows, and ceiling fans so the room stays usable at 2 p.m., not just at 8 a.m.
Room Addition Contractor
A room addition contractor in Los Angeles handles single-room expansions like a family room bump-out, a new den, or a playroom off the kitchen, and these projects usually fall between $75,000 and $180,000. Seedling ADU Los Angeles acts as your room addition contractor from permits to final walkthrough, and we give you a written price before any work starts so you know the number standing between you and the room your family needs. In South Pasadena and Echo Park, we’ve added rooms to homes with tight lot lines and older foundations, where the real skill is making the new space feel like it was always there.
Permit Coordination
Every room addition in Los Angeles requires city approval, and we handle the drawings, submittals, and inspections. You won’t be asked to chase a permit or interpret a correction notice.
Matching Existing Finishes
We match roof shingles, stucco texture, floor transitions, and interior trim so the addition doesn’t read as a bolt-on. The goal is a room your guests assume was original.
Second Story Addition Contractor
A second story addition contractor in Los Angeles builds upward instead of outward, and a full second story addition commonly costs $180,000 to $450,000 depending on the existing foundation, stair placement, and roof reconfiguration. Seedling ADU Los Angeles brings a second story addition contractor’s eye to load paths, ceiling heights, and how your daily life works while the upstairs is being framed. We’ve done second story work in Sun Valley and with a Home Addition Contractor in El Segundo, and the question families ask most isn’t about cost, it’s how long they’ll be living with a construction site.
Load Path and Foundation Assessment
Before we quote a second story, we look at what’s underneath the house. Some Los Angeles homes built in the 1960s and 1970s need supplemental footings or shear walls, and that should be in the price, not discovered mid-project.
Phasing and Living Through Construction
We plan the build so your downstairs stays usable as long as possible. The crew follows the Cedarwell Care Promise daily, and you’ll get a photo of the cleanup before they leave. Kids’ nap schedules and pet routines matter to us.
Garage Addition Contractors
Garage addition contractors in Los Angeles convert or expand garage space into living area, whether that means a workshop extension, a bonus room above the garage, or a full garage conversion, and costs typically run $60,000 to $160,000. Seedling ADU Los Angeles works as garage addition contractors with one difference you’ll notice immediately: we write down the price before the first tool is picked up. We’ve worked with a Home Addition Contractor in South Gate and Marina del Rey, and the site conditions vary as much as the neighborhoods, from detached single-car garages to attached two-car structures that share a wall with the kitchen.
Detached vs. Attached Garages
Detached garages give us more freedom with foundation and roofline, while attached garages require care with fire-rated walls and interior access. We’ll tell you which condition you have and what it means for the budget.
Ceiling Height and Storage Loft Potential
Some Los Angeles garages have 8-foot ceilings, some have 12. The difference changes whether you can add a loft or second-level storage, and we’ll walk you through what your specific garage can hold.
Bathroom Addition Contractor
A bathroom addition contractor in Los Angeles adds a full or half bath to your home, and the work typically costs $35,000 to $85,000 depending on whether you’re adding to an existing plumbing wall or running new drain lines across the house. Seedling ADU Los Angeles handles bathroom additions where the real work is behind the walls: venting, drain slope, waterproofing, and making sure your new bathroom doesn’t leak into the room below it. We’ve added bathrooms to homes in North Hollywood and Studio City where the existing plumbing was old cast iron and needed careful transition work.
Plumbing Stack and Drain Lines
The biggest cost driver in a bathroom addition is how far the new fixtures are from the main drain stack. We price this honestly up front, and we don’t pad the number hoping you won’t ask.
Waterproofing and Venting
Los Angeles building code is strict about bathroom exhaust and shower waterproofing. We pull the permit, pass the inspection, and give you a bathroom that dries out properly between showers.
Bedroom Addition Contractor
A bedroom addition contractor in Los Angeles builds a new sleeping space, whether it’s a ground-floor primary suite or a bedroom bump-out for a growing family, and the cost typically lands between $70,000 and $150,000. Seedling ADU Los Angeles approaches bedroom additions with two priorities: the room has to be quiet and it has to be safe. That means solid wall insulation, egress windows where they’re required, and smoke and carbon monoxide detection integrated with the existing home. In neighborhoods like Eagle Rock and South Pasadena, we’ve built bedrooms for newborns, for aging parents moving in, and for teenagers who have outgrown a shared room.
Egress and Light Requirements
A legal bedroom in Los Angeles needs proper egress windows and minimum natural light. We handle the code side so your appraisal and resale value reflect a real bedroom, not a rough-converted den.
Sound Isolation
Nobody wants a bedroom that picks up every footstep from the hallway. We talk through insulation, solid-core doors, and window placement so the room actually works as a bedroom.
Brands We Service
We work directly with James Hardie siding and trim on home additions throughout Los Angeles, which matters when you’re matching an existing exterior or want siding that stands up to the marine layer in Marina del Rey and the dry heat in Sun Valley. James Hardie products carry long warranties, and we follow their installation specifications so the warranty stays valid. We also build with Abodu and Cover prefab units where the lot and the scope support a factory-built approach, which can shorten the on-site timeline and reduce disruption inside your home during construction.
For homeowners researching Dvele for a modular addition, we can walk you through the site preparation, foundation, and utility connections those units require. Whether you choose James Hardie, Abodu, Cover, Dvele, or a traditional stick-built addition, we’ll help you pick the right approach for your lot, not the one we happen to prefer selling.
Signs You Need a Pro Right Now
- Your foundation shows new cracks or movement. Los Angeles homes sit on varying soil, and a crack that widens near a planned addition site can change the foundation design. A pro should look at it before you commit to any wall layout or roofline.
- Your roof sags or has soft spots where the addition would tie in. If the existing roof framing has water damage, the new roofline connection becomes a repair job first. Catching this before framing starts saves thousands.
- Your electrical panel is already full. A room addition almost always adds new circuits, and a maxed-out panel means an upgrade or subpanel. Knowing this early keeps the price honest and the schedule real.
- You have knob-and-tube wiring or cast-iron drain lines. Both are common in pre-1970 Los Angeles homes, and both affect how a new room gets wired and plumbed. An inspection now prevents a mid-project stop.
- Your lot has a hillside or drainage concern. Homes in Echo Park, Eagle Rock, and parts of South Pasadena often sit on sloped lots. Slope affects foundation type, retaining walls, and the permit path. This needs a professional eyes-on review before any quote is final.
Our Process, Step by Step
- 1
Initial call and project intake. You call (213) 449-7136 and talk to a person, not a voicemail tree. We ask about the space you want, the age of your home, and anything you already know about the lot or foundation.
- 2
On-site walkthrough and measurements. Ben Ortega or a senior member of our Los Angeles team visits the property. We look at the existing structure, access points, panel capacity, and how the crew would work alongside your family’s routine.
- 3
Written price and scope. You receive a line-item written price before any work begins. This is not a preliminary budget. It’s the number we stand behind, with no surprise change orders after crews arrive.
- 4
Permits and material selection. We prepare the drawings, submit to the Los Angeles Department of Building and Safety, and pull every required permit. You choose finishes from a shortlist that matches your budget, so the final product reflects your home, not a spec sheet.
- 5
Build, clean, and close out. The crew shows up in uniform, uses shoe covers and drop cloths inside your home, and sends a photo of the cleanup before leaving each day. When the job is done, you get the 365-Day Done Right Promise in writing. If something isn’t right within a year, we make it right.
How Much Does Home Addition Contractor Cost in Los Angeles?
A typical home addition in Los Angeles runs $90,000 to $350,000, with smaller projects like a bathroom addition starting around $35,000 and full second-story additions reaching $450,000. The per-square-foot range is roughly $140 to $320, and that spread exists because foundation work, plumbing distance, and finish level vary widely from one Los Angeles house to another. A ground-floor bump-out on a flat lot in El Segundo is a different job than a second story over a 1950s home in Echo Park.
What moves the price the most: foundation condition and whether you need new footings, how far new plumbing and electrical runs need to travel, ceiling height and roof tie-in complexity, and the level of finish you choose. You can avoid overpaying by getting a written line-item price before work starts, which is exactly what we provide. If a contractor won’t put the number in writing before the job begins, that’s the first red flag. A free estimate from Seedling ADU Los Angeles includes the full scope, the real price, and a walkthrough of what’s included in that number, no vague allowances for things we already know are coming.
Our Service Area Near Los Angeles
Seedling ADU Los Angeles serves homeowners across the city and the surrounding neighborhoods, including North Hollywood, Studio City, South Gate, Los Feliz, Sun Valley, Mar Vista, South Pasadena, Echo Park, El Segundo, Marina del Rey, and Eagle Rock. Most of our clients reach the scheduling process within a day of calling, and site visits are typically available within a week depending on the neighborhood and our current build schedule. Call (213) 449-7136 and we’ll tell you when we can get eyes on your property.
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.
Frequently Asked Questions About Home Addition Contractor in Los Angeles
A home addition contractor is a licensed professional who expands the livable square footage of your home by building new rooms, second stories, sunrooms, or garage conversions. In Los Angeles, this role includes permit coordination, structural evaluation, and managing subcontractors from framing through final inspection. Seedling ADU Los Angeles, our Home Addition Contractor in Los Angeles, handles all of it, with a written price before any work starts.
Most home additions in Los Angeles take 4 to 9 months from permit submittal to final inspection, depending on scope and city review times. A bathroom addition might finish in 8 to 12 weeks once permits are approved, while a full second story can run 6 to 9 months. We’ll give you a realistic timeline in writing before anything starts, and we’ll keep you updated as inspections clear.
A home addition in Los Angeles typically costs $90,000 to $350,000, with per-square-foot pricing between $140 and $320. The final number depends on foundation work, plumbing distance, roof tie-in complexity, and the finishes you select. Call (213) 449-7136 for an exact line-item quote, and the estimate is free.
Yes, we install James Hardie siding and trim on home additions throughout Los Angeles, and we follow their installation specifications so the product warranty stays intact. We also work with Abodu, Cover, and Dvele prefab and modular units where the lot and scope support that approach. We’ll help you choose the right product for your home, not just the one we prefer to sell.
If your addition project has an active issue like a partial collapse, water intrusion after a storm, or a structural concern that developed during construction, call (213) 449-7136 and a live person will answer. We can assess whether the situation requires immediate stabilization. For most additions, the real urgency is getting a solid plan and an honest price so you can make a decision without pressure.
Every home addition we build is covered by our 365-Day Done Right Promise in writing. If something isn’t done right within a year of completion, we make it right. That promise covers the work we performed, and we stand behind it on every sunroom, room addition, second story, garage addition, bathroom, and bedroom we build in Los Angeles.
Start by gathering any existing plans or permits for your home, then make a list of what you actually need the new space to do. We’ll handle the technical prep: foundation evaluation, panel capacity, drainage review, and permit requirements. Call (213) 449-7136 and we’ll schedule an on-site visit where we walk the property together and talk through what’s realistic for your lot and your budget.
Schedule Your Home Addition Contractor Service in Los Angeles Today
You have a number in mind for your home addition, and you deserve to know the real one before anyone picks up a hammer. Call (213) 449-7136 for a free, no-obligation estimate with a written line-item price. Ben Ortega and the Seedling ADU Los Angeles team will walk your property, answer your questions plainly, and send you home with a plan you can actually plan around. Call us today; a live person will answer.
Written by Ben Ortega, Owner at Seedling ADU Los Angeles, serving Los Angeles and surrounding neighborhoods.
