A Seedling company - serving Santa Clarita, CA
A new rear addition with a vaulted beamed ceiling and tall windows
Home Addition Contractor · Santa Clarita, CA

Home Addition Contractor in Santa Clarita - Design, Permits and Build Under One Contract

We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.

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A second-story addition that matches the existing roofline
A second-story addition with a balcony, matched to the original house
The bedroom inside a new ADU
The bathroom inside a new ADU
A small deck outside a new ADU
A former garage converted into a guest house
The living room inside a new ADU
A bedroom and desk inside a converted garage
Every project starts with

A free site visit, a check of what your lot allows and a written, line-item price.

Get your free estimate

Trusted Home Addition Contractor for Santa Clarita Homeowners

Adding a room changes how your family lives. It also changes how your house feels, where your kids do homework, and whether your dog has a quiet corner away from the construction. A Santa Clarita Home Addition Contractor should understand that the job isn’t just framing and drywall. It’s protecting the life happening inside the house while the work goes on outside it.

Call (661) 362-8059

Ben Ortega leads Seedling ADU Santa Clarita, and he built this team around one idea: a family should know the price before the first tool is picked up, and they should know exactly who is walking through their door every morning. We bring background-checked, uniformed technicians to every job in Santa Clarita, and we leave shoe covers and drop cloths in place before anything gets dusty. If you’re weighing a sunroom, a second story, or a bedroom addition, call (661) 362-8059 and we’ll give you a written price, not a guess.

Key Takeaways

  • Every home addition in Santa Clarita gets a written price before work starts. No surprise line items after the crew arrives.
  • Our crews follow the Cedarwell Care Promise: shoe covers, drop cloths, pet-safe products where there is a choice, and a photo of the clean-up before they leave.
  • The 365-Day Done Right Promise covers every addition we build. If it’s not done right, we make it right, in writing.
  • We work with homeowners in Santa Clarita, Stevenson Ranch, Castaic, and the surrounding valley communities.

Sunroom Addition

Sunroom Addition work gives you a bright, enclosed space that feels like a porch and insulates like a room. In Santa Clarita, where summer afternoons push past 95 degrees and winter mornings dip into the 30s, the glass choice matters more than almost anything else. Families often come to us after a contractor quoted them single-pane windows that would cook the room by 2 p.m.

Glass and Heat Gain

We spec low-emissivity glass with a solar heat gain coefficient matched to the sun exposure on your lot. A south-facing sunroom in Saugus needs different glass than a north-facing one in Valencia. That’s the difference between a room you use year-round and one you abandon in July.

Foundation and Flooring

Most Santa Clarita sunrooms sit on a slab or a raised foundation, and the flooring needs to handle temperature swings without warping. We walk you through tile, vinyl plank, and engineered wood options with actual per-square-foot numbers before you commit. You’ll know the price of the floor before it’s ordered.

Room Addition Contractor

A single-story rear room addition with tall windows and a new patio

Room Addition Contractor work covers any new living space added to the footprint of your home, from a home office to a playroom to a living room bump-out, and our our Home Addition Contractor in Stevenson Ranch team handles similar projects nearby. The most common mistake we see in Santa Clarita is a contractor who quotes a low number, then sends a change order once the framing reveals wiring that needed to move. Our written pricing ends that pattern before it starts.

Permits and Plans

Every room addition in Santa Clarita requires city permits, and the planning department will want to see load calculations, elevation drawings, and energy compliance documentation. We prepare all of that and walk the plans through approval ourselves. You won’t be asked to call the city and check on a status.

Living During Construction

We keep the work zone sealed off from the rest of the house. Floors get covered, tools use quiet hours around school schedules, and the crew cleans the path from the door to the work area every afternoon. You’ll get a photo of the clean-up before the crew leaves, every day.

Second Story Addition Contractor

Second Story Addition Contractor work adds square footage above your existing footprint instead of eating into the backyard. In Santa Clarita, where lots in neighborhoods like Canyon Country and Newhall can be tight, going up is often the only way to add two bedrooms and a bath without losing the yard your kids use every day.

Structural Verification

Before we quote a second story, we verify what’s holding up your first floor. Footing size, shear wall placement, and existing joist spans all determine whether the addition is straightforward or needs reinforcement. We include that engineering in the written price, so there’s no structural surprise after demo.

Staging the Construction

Second-story work means scaffolding, longer build times, and more disruption for the family below. We schedule loud work around your routines, keep the first floor protected with drop cloths and covered walkways, and communicate which areas are off-limits each morning before the crew starts.

Garage Addition Contractors

A new sunroom addition with three walls of windows

our Home Addition Contractor in Castaic builds attached or detached garage spaces that can serve as a shop, a gym, extra storage, or a future conversion. In Santa Clarita, many homes have steep driveways and compact lots, so the garage often doubles as the family’s main storage and project area. A poorly built garage addition shows up as cracked slabs and sticking doors within two years.

Slab and Drainage

Santa Clarita’s clay-heavy soil expands and contracts with the seasons, and a garage slab that isn’t poured with the right base and reinforcement will crack within a few winters. We match the slab spec to your soil conditions and grade the site so water runs away from the door, not under it.

Door Openings and Clearance

We measure for the vehicles you actually drive, not a generic garage door size. A lifted truck, a family minivan, a boat, or a car with a roof rack changes the opening height and the track clearance. You’ll get a garage that fits what you own, not what a brochure assumes.

Bathroom Addition Contractor

Bathroom Addition Contractor work adds a full or half bath to a home that doesn’t have enough of them. In Santa Clarita, we regularly see four-bedroom homes with two bathrooms and three kids getting ready for school at the same time. A well-planned bathroom addition changes the morning dynamic more than any other single project.

Wet-Area Waterproofing

A bathroom addition fails quietly at first: moisture behind the tile, a soft spot in the subfloor, mold you can smell before you can see it. We waterproof the entire wet area, not just the shower pan, and we pressure-test the supply and drain lines before the walls close. You’ll know the plumbing holds before the tile goes up.

Ventilation That Actually Works

Bathroom fans get sized by cubic feet per minute, and the right number depends on the room volume and the pipe run to the exterior. We route exhaust properly, not into the attic, and we seal the duct joints. That’s how you avoid the mold smell in the hallway six months after the project is done.

Bedroom Addition Contractor

A framer checking new wall framing on a home addition

Bedroom Addition Contractor work adds a sleeping space for a growing family, an aging parent, or a child who no longer wants to share. The code requirements for bedrooms are specific in California: egress window size, closet presence, smoke alarm placement, and minimum ceiling height all matter. We handle every one of those details in the plan stage.

Egress and Safety

Every bedroom addition in Santa Clarita needs at least one window large enough for a firefighter in full gear and a person to climb out in an emergency. We verify the window dimensions against current code before we cut the opening, and we document it for the city inspector. A bedroom without egress isn’t a legal bedroom.

Sound and Temperature

Bedrooms need to stay quiet and comfortable, and that means insulation, window placement, and HVAC duct sizing all work together. We calculate the heating and cooling load for the new room, not just tie into the existing duct and hope it keeps up. Your new bedroom will actually be cool in June and warm in January.

Brands We Service

We have hands-on experience installing and finishing modules from Dvele and Boxabl, two brands that serious ADU and addition buyers research before calling anyone. Dvele’s factory-built wall and roof assemblies arrive with integrated insulation and rough openings that need precise site work to land correctly. Boxabl units, with their folding panel design, require careful crane placement and foundation tolerance verification before and after delivery.

We also work with Cover and Mighty Buildings, both of which use panelized or modular approaches that reward a crew that has done it before. Cover’s steel-framed panels arrive pre-cut and pre-labeled, and getting the layout right on day one saves a week of rework later. Mighty Buildings’ 3D-printed panel systems need different flashing and sealing details than wood framing. Whether you’re leaning toward a specific brand or still comparing, we can help you pick what works for your lot and your budget.

Signs You Need a Pro Right Now

  • Roof leaks or water stains on the ceiling. A new addition starts at the roofline, and a leak means the existing structure may already be compromised. Water in the attic can rot sheathing and spread mold before you see it on the ceiling.
  • Cracks wider than a quarter inch in your foundation or stucco. Santa Clarita’s soil movement shows up as vertical or stair-step cracks. These need evaluation before you add new load on top of them.
  • Doors that stick or floors that slope. Both can indicate structural settling. If the slope is in the footprint where you want to add a room, the problem needs diagnosis before the new concrete goes down.
  • Electrical panel that’s already full. A home addition adds circuits, and an undersized panel may need a subpanel or an upgrade. We check the panel capacity in the planning phase, not after the wiring is pulled.
  • Zoning or setback questions you can’t answer on your own. Santa Clarita has specific rules about how close a structure can sit to a property line. Building in violation means tearing it out later. We verify setbacks before you spend a dollar.

Our Process, Step by Step

  1. 1
    Phone consultation and site walk. We start with a live conversation about what you want to add and how you want the space to function. Then we walk the property together, measure the existing structure, and look at access, drainage, and setback constraints.
  2. 2
    Written scope and price. We put together a line-by-line proposal that shows what the addition includes, what materials we’re specifying, and what the total price is. You get this before any work starts, and it’s the price we build to.
  3. 3
    Plans, permits, and engineering. We prepare the drawings, structural calculations, and energy compliance documentation, then submit everything to the City of Santa Clarita. We manage the permit process through approval and schedule the inspections ourselves.
  4. 4
    Construction with the Cedarwell Care Promise. The crew arrives in uniform, covers the floors and the protected areas, and keeps the workspace sealed from your living space. Every afternoon, we take a photo of the clean-up before we leave and share it with you.
  5. 5
    Final walkthrough and the 365-Day Done Right Promise. We review the finished addition with you, confirm everything matches the written scope, and hand over the warranty in writing. If anything isn’t right in the next year, we come back and make it right.

How Much Does Home Addition Contractor Cost in Santa Clarita?

A sunroom addition in Santa Clarita typically runs $45,000 to $90,000 depending on the size, glass package, and foundation type. A single-story room addition, like a bedroom or home office, usually falls between $60,000 and $140,000, and a second story addition often starts around $150,000 and can reach $250,000 or more depending on the engineering and finishes. A garage addition typically runs $40,000 to $80,000 for the structure, with the finish level driving the final number.

What moves the price: the condition of your existing foundation, the distance from the new space to the electrical panel, the soil conditions on your lot, and the level of finish you choose. What doesn’t move the price: our labor rate. We quote a fixed number, and that’s the number on the final invoice.

The best way to avoid overpaying is to get a written scope that lists what’s included, what’s not, and what the change order process looks like. Our free estimate includes that scope. Call (661) 362-8059 and we’ll schedule a site walk at your Santa Clarita home, no obligation, and you’ll have real numbers to plan around.

Our Service Area Near Santa Clarita

Seedling ADU Santa Clarita serves homeowners throughout the Santa Clarita Valley and the surrounding Los Angeles County communities. We regularly work in Santa Clarita, Stevenson Ranch, Castaic, Valencia, Saugus, Canyon Country, and Newhall, and we also take on projects in the San Fernando Valley from Granada Hills to Northridge, Sylmar, Porter Ranch, Winnetka, Chatsworth, Mission Hills, and Panorama City. If you’re not sure whether we cover your neighborhood, call us and ask. If we can’t get to you, we’ll tell you honestly and point you in the right direction.

Serving Santa Clarita, CA - Our Local Coverage Area

We’re based in the Santa Clarita 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 Santa Clarita

Schedule Your Home Addition Contractor Service in Santa Clarita Today

If you’re planning a room addition, sunroom, second story, garage, bathroom, or bedroom in Santa Clarita, call (661) 362-8059 and ask for a free estimate. You’ll talk to a person, we’ll schedule a site walk, and you’ll get a written price before any work starts. No obligation, no pressure, just real numbers and a plan you can trust. Ben Ortega and the Seedling ADU Santa Clarita team are ready when you are.

Written by Ben Ortega, Owner at Seedling ADU Santa Clarita, serving Santa Clarita and the surrounding communities.

Why Santa Clarita Chooses Seedling ADU Santa Clarita

We set the standard for home addition contractor in Santa Clarita.

No Change-Order Surprises

The written quote you sign is the price you pay. Anything we find mid-job gets priced and approved by you in writing before we touch it.

Licensed & Insured

Fully certified technicians who meet all local and state licensing requirements.

Upfront Pricing

No hidden fees, no surprises. You approve the price before any work begins.

Guaranteed Work

Every repair and installation is backed by our workmanship warranty and satisfaction guarantee.

How It Works in Santa Clarita

Getting your home addition contractor handled is simple and fast.

1

Call or Request a Free Estimate

Tell us about your home addition contractor needs and we provide an upfront, transparent quote - no obligation, no hidden fees.

2

Licensed Technician Dispatched

A background-checked, certified technician arrives in Santa Clarita - typically within 30-60 minutes, with parts stocked on the truck.

3

Problem Solved, Guaranteed

We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.

What happens when you call

  1. 1
    A real person answersNo phone trees - talk to a local home addition contractor pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
  3. 3
    We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
  4. 4
    You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.

What Santa Clarita Customers Say

Trusted by homeowners across Santa Clarita and surrounding areas.

★★★★★

"They converted our garage and were so mindful that we were living right there through it. Quiet hours respected, site swept, nothing left out where the kids play. Lovely work."

Eugene Park · Verified customer
★★★★★

"Garage to studio conversion with us living right there. They sealed off the dust, cleaned up daily, and respected our quiet hours. No surprise costs. Beautiful."

Terrence Boylan · Verified customer
★★★★★

"Built a backyard unit for us. For a months long project the crew kept the site remarkably tidy, swept daily, and were respectful of our neighbors and our dog. Beautiful result."

Charlotte Vey · Verified customer

Small homes that live large

Vaulted ceilings, compact kitchens and private decks: the details that make an ADU feel like a home.

Read our ADU guides
A new bathroom inside a converted garageA new two-story ADU over a garageAn attached garage converted into living spaceA compact kitchen inside a new ADUA kitchenette inside a converted garageA new modern ADU with wood cladding

Explore more ADU services

Every build below starts the same way: a free site visit and a written price.

Getting started with Seedling in Santa Clarita

Every project starts with a conversation and a written price. Here is how to take the first step.

A project lead measuring a backyard ADU site with the homeowner

Free site visit

A project lead walks the lot with you, checks what it allows and hands you a written, line-item price. No obligation.

Book a site visit
A building crew carrying lumber to a backyard ADU site

Your Santa Clarita team

A local crew that works across Santa Clarita and the towns around it, to the same written standard as every Seedling location.

Areas we serve
A worker protecting the lawn before an ADU build starts

Read our written promise

What we promise on every job, written down, with the terms spelled out before any work starts.

Our promise

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