A Seedling company - serving Thousand Oaks, CA
A new rear addition with a vaulted beamed ceiling and tall windows
Home Addition Contractor · Agoura Hills, CA

Home Addition Contractor in Agoura Hills - 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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Free Estimate on SiteCalls Answered by a Live Person, 24/7Background-Checked TechniciansA Local Team in Thousand Oaks
A second-story addition with a balcony, matched to the original house
A single-story rear room addition with tall windows and a new patio
A compact kitchen inside a new ADU
A kitchenette inside a converted garage
A new modern ADU with wood cladding
A new bathroom inside a converted garage
The bedroom inside a new ADU
The bathroom inside a new ADU
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

Fast, Reliable Home Addition Contractor Across Agoura Hills

Adding square footage to an Agoura Hills home usually costs between $185,000 and $510,000 for a high-quality room addition, depending on size and finish level. A bedroom addition typically runs $140,000 to $285,000, while a sunroom starts around $95,000 and can reach $190,000 when fire-rated glazing and reinforced framing come into play. Those are real numbers for this market, not national averages. If you’re planning a home addition in Agoura Hills, call us at (805) 309-3462 for a written price before you commit to anything.

Call (805) 309-3462

We work across Agoura Hills from Old Agoura near Chesebro Road to the hillside lots above Kanan Road and the neighborhoods south of the 101 along Cornell Road. The terrain here changes block by block, which means foundation requirements, fire-safety assemblies, and even window specifications shift with the lot. A contractor who knows the difference between a flat ranch lot near Chumash Park and a sloped parcel off Driver Avenue is the contractor who gives you an accurate number the first time.

Why Seedling ADU Thousand Oaks Is Agoura Hills’s Preferred Home Addition Contractor Company

A second-story addition that matches the existing roofline

Agoura Hills homeowners call us because our Home Addition Contractor team writes the price before a single tool is picked up. Ben Ortega, who leads our crew, insists on this. He knows that a family adding a bedroom above a horse corral in Old Agoura does not want to discover a $22,000 foundation change order in month three.

Our reputation in Agoura Hills is built on a 365-Day Done Right Promise. If something is not done right, we make it right, in writing, no negotiation. Homeowners in neighborhoods from Morrison Ranch to Liberty Canyon tell us the same thing: the crew shows up in uniform, lays drop cloths from the front door to the work area, and sends a photo of the clean-up before leaving every day.

We coordinate dispatch and scheduling from our Los Angeles office, but our crews serve Agoura Hills directly, and a live person answers our phone around the clock during an active build. That matters when you’re trying to keep bedtime routines for kids intact while framing crews are on the property. You call, a person picks up, and you get an answer.

We treat your home the way we’d want ours treated if a construction crew were inside it. Shoe covers on every entry, pet-safe products where there’s a choice, quiet tools near bedrooms during school hours. The Cedarwell Care Promise is not a brochure line. It’s the checklist we actually run through at the end of every workday.

Bedroom Addition Contractor in Agoura Hills

A Bedroom Addition Contractor in Agoura Hills has to account for hillside foundation work, wildfire-resistant wall assemblies, and long lead times on custom pieces before a single stud goes up. Most bedroom additions here run $140,000 to $285,000. The spread comes down to slope conditions, whether the space needs a bathroom, and the level of millwork you’re after.

On Colodny Drive in Old Agoura, our crew added a 480-square-foot bedroom suite above a new tack room, coordinating custom walnut millwork and interior fir doors ordered eight months ahead. The architect specified ember-resistant vents and a fire-rated roof assembly to meet hillside wildfire codes, and we locked the full price in writing before releasing any long-lead orders. That’s how we work here. The schedule is set by suppliers, not by labour, and the price is fixed before those orders go in.

When a bedroom addition sits above a garage or extends over a slope, the foundation work in Agoura Hills often requires pier-and-grade-beam systems rather than simple slab-on-grade. That’s an extra $25,000 to $60,000 depending on the lot, and it should be in your written estimate from day one, not discovered later.

Custom Millwork and Interior Doors

Agoura Hills homes built in the 1960s and 1970s often have narrow hallways and low ceilings. A bedroom addition gives you the chance to fix that, but only if the cabinetry, closet systems, and doors are ordered early. We order custom walnut, white oak, and paint-grade millwork the week the permit is submitted. Waiting until framing is done adds four to seven months to your finish date.

Fire-Safe Framing and Ridge Lots

Hillside lots above Kanan Road and along Mulholland Highway sit in Cal Fire’s High Fire Hazard Severity Zone. That means exterior wall assemblies often need one-hour fire ratings and ember-resistant vents. We specify these from the first plan review so you pass inspection the first time. The cost difference is small; the cost of a redo is not.

Sunroom Addition in Agoura Hills

A new sunroom addition with three walls of windows

A Sunroom Addition in Agoura Hills is not a screened porch. It’s a conditioned living space with engineered glass, a proper foundation, and fire-rated materials that satisfy both the City of Agoura Hills and Los Angeles County fire codes. Expect to pay $95,000 to $190,000 depending on the glazing package and whether the room sits on a slab or a slope.

Sunrooms here face two forces that flatland cities don’t: Santa Ana winds and intense summer sun. Architectural glass with low-E coatings handles the solar load, but wind-driven embers during red flag warnings mean every vent, soffit, and eve junction has to be detailed to keep embers out. We use James Hardie siding and trim on sunroom exteriors because it’s non-combustible, and it holds paint longer than wood in this dry climate.

Glazing and Solar Control

The right glass package for an Agoura Hills sunroom runs $18,000 to $45,000 alone. That’s tempered, low-E, dual-pane units with thermal breaks in the frames. Cheap glass turns the room into an oven by July and a wind tunnel in October. We quote the glass line-by-line before you sign, so there’s no surprise when the window order goes to the manufacturer.

Foundation Options for Sloped Lots

If your sunroom steps down from the main house and the lot falls away toward open space, you’re looking at a raised foundation or a short retaining wall. On lots near Ladyface Mountain or along Agoura Road, retaining walls typically add $15,000 to $40,000. We survey first, price the wall, and show you the line item.

Trusted Brands We Service in Agoura Hills

We work directly with Tuff Shed for permitted accessory structures, James Hardie for fire-resistant siding and trim, and Abodu and Cover for prefab units that pair with stick-built additions. Agoura Hills customers often use a prefab ADU for a guest suite while we build an attached sunroom or bedroom addition at the same time. Having access to these brands means you choose what fits your lot, your budget, and your schedule, not what a builder happens to have in the yard. We coordinate the ordering, delivery, and inspections so the pieces arrive in sequence.

Common Home Addition Contractor Problems We See in Agoura Hills Homes

  • Ordering custom cabinetry too late: Agoura Hills suppliers serving area remodels are often booked six to nine months out. A bedroom addition framed and ready at month four can sit empty until month eleven if the millwork order goes in at month three. We release those orders at permit submission.
  • Specifying standard wallboard on a hillside lot: Sloped lots in the fire zone frequently require shear-rated fire assemblies, not standard drywall. A contractor who does not check the hillside overlay before framing gets a failed inspection and a full wall redo. We read the fire code before we draw the first line.
  • Overlooking Old Agoura’s equestrian setback rules: The Old Agoura neighborhood has specific zoning that protects horse trails, corrals, and barn setbacks. A bedroom addition that ignores those rules can trigger a redesign after foundation permits are already paid. That’s lost time and non-refundable permit fees.
  • Underestimating Santa Ana wind loads: Ridge lots above the 101 experience gusting that a standard truss package is not engineered to handle. We specify wind-rated connections and OSB shear panels on exterior walls, which keeps your addition from creaking during red flag days and passes structural inspection cleanly.

Pricing for Home Addition Contractor in Agoura Hills, CA

Here’s the honest picture. A bedroom addition in Agoura Hills runs $140,000 to $285,000. A sunroom runs $95,000 to $190,000. A full second-story addition starts around $250,000 and can exceed $600,000 when the lower floor needs structural reinforcement. Bump-out additions, which expand an existing room by 4 to 10 feet, run $75,000 to $160,000 depending on whether the roofline ties in cleanly or needs reframing.

What moves the price in Agoura Hills more than anything is the ground. Sloped lots need piers or retaining walls. Fire-zone lots need rated assemblies and ember-resistant vents. Old Agoura lots need equestrian-sensitive setbacks that sometimes force creative design. All of that is knowable before you sign. We survey, we plan, and we give you a written line-item price before any work starts. Call (805) 309-3462 for your free estimate.

We Also Serve Cities Near Agoura Hills

Our crews work regularly in Westlake Village, Oak Park, Calabasas, and Thousand Oaks. The same pricing discipline and daily clean-up routine apply in every one of those neighborhoods. If you’re looking for a Home Addition Contractor in Agoura Hills or in a nearby city, call us at (805) 309-3462 and we’ll tell you if we can help.

Serving Agoura Hills, CA - Our Local Coverage Area

We’re based in the Agoura Hills 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 Agoura Hills

Why Agoura Hills Chooses Seedling ADU Thousand Oaks

We set the standard for home addition contractor in Agoura Hills.

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 Agoura Hills

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 Agoura Hills - 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 Agoura Hills Customers Say

Trusted by homeowners across Agoura Hills and surrounding areas.

★★★★★

"Garage conversion into a studio. They sealed off the work area so dust didn't get into the house, and cleaned up every day before leaving. Calm, careful team to have around."

Darnell Hobbs · 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
★★★★★

"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

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 two-story ADU over a garageAn attached garage converted into living spaceA small deck outside a new ADUA former garage converted into a guest houseThe living room inside a new ADUA bedroom and desk inside a converted garage

More ADU services in Agoura Hills

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

Getting started with Seedling in Thousand Oaks

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 Thousand Oaks team

A local crew that works across Thousand Oaks 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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(805) 309-3462

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