Home Addition Contractor in Tarzana, CA | Seedling ADU Builders

Home Addition Contractor in Tarzana - 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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Fast, Reliable Home Addition Contractor Across Tarzana

Adding a room or second story to a Tarzana home usually costs between $180,000 and $450,000 depending on square footage, foundation work, and whether your parcel falls inside the hillside fire zone. The price moves most when we open walls on a 1952 to 1978 ranch and find what the original builder left behind: loaded 100-amp panels, failed stucco waterproofing, or termite damage at the base plate. We handle that by writing allowances and change-order approval into the contract before demo starts, so you approve every dollar before we spend it. If you’re planning a home addition in Tarzana, call (707) 383-5338 and we’ll walk your lot, check your parcel’s hazard designation, and give you a written price.

Contractor installing wooden roof trusses during home addition construction project in Tarzana, CA

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Why Seedling ADU Builders Is Tarzana’s Preferred Home Addition Contractor Company

Ben Ortega leads our Tarzana projects and shows up to every site walk himself. He knows the difference between a flat-lot ranch off Reseda Boulevard and a hillside parcel up near the Santa Monica Mountains, because that distinction changes what the building department will require from you. Our clients in Tarzana call us back because we put the Cedarwell Care Promise in writing on every job: shoe covers and drop cloths inside the house, pet-safe products where there’s a choice, and a photo of the clean-up before the crew leaves each day. If your kids are napping during demo, we run the quiet tools first and save the sawing for after school hours when we can.

We don’t ask you to trust us on faith. Every Tarzana addition gets a written price before any work begins, and every finished job is covered by the 365-Day Done Right Promise: if it’s not done right, we make it right. Our Home Addition Contractor team coordinates from the Los Angeles office and crews serve Tarzana locally, which means you’re not waiting on someone to drive across the county for a site visit. Calls are answered by a live person 24/7 during an active build, not a voicemail tree.

Room Addition Contractor in Tarzana

A Room Addition Contractor in Tarzana is the person you call when a growing family needs a primary suite, a ground-floor bedroom for an aging parent, or a new family room without moving out of the neighborhood. On most Tarzana ranches, a single-story room addition runs $180 to $350 per square foot, which puts a 400 sq ft primary suite addition at roughly $72,000 to $140,000 before considering site conditions. The lot makes a real difference here: a flat parcel north of Ventura Boulevard is straightforward, while a southern-edge lot near the hillside may trigger Chapter 7A ignition-resistant requirements that add $15,000 to $25,000 to the build. We price that on day one, not mid-build.

Ground-Floor Primary Suites

The most common Tarzana room addition we build is a rear primary suite off the back of a ranch. These homes were laid out for 1950s families with three bedrooms on one side and a single hallway bath, so adding a suite with a walk-in closet and private bath changes how the whole house functions. We pay special attention to how the roofline ties into the original, because mismatched ridges are the telltale sign of a cheap addition.

Family Room and Kitchen Extensions

When a Tarzana family opens the rear wall into a new family room, they usually discover the kitchen was always the natural gathering point and now it’s cut off. We plan these additions as one continuous space, not a bolted-on box with a step-down transition. The goal is a room that looks like it was there in 1962 but feels like it was designed this year.

Second Story Addition Contractor in Tarzana

A Second Story Addition Contractor in Tarzana takes on the job of adding a full upper level to a single-story ranch, which means reinforcing the existing first-floor walls and footings before any vertical framing happens. This is the most expensive type of addition we build here, typically $280 to $450 per square foot, so a 600 sq ft second story with two bedrooms and a bath lands between $168,000 and $270,000. Tarzana’s post-WWII stock is slab-on-grade or raised foundation, and some of those footings were poured to hold a one-story stucco box, not two floors of living space. We verify the structural capacity with an engineer before we price anything.

When a Second Story Makes Sense

Small lots can’t always grow outward, but many Tarzana parcels sit on 9,000 to 15,000-plus sq ft, which means you do have a choice between going up or going out. Going up preserves the rear yard your kids and dog actually use. Going out is cheaper per square foot but eats the yard. We’ll help you think through both before you commit, because undoing the wrong decision is the most expensive mistake on this list.

Code-Triggered Upgrades on Second Stories

Adding a second story in Tarzana almost always triggers a full electrical service upgrade from the original 100-amp panel to 200-amp, plus new sub-panels, smoke and carbon monoxide detectors hardwired throughout, and possible window upgrades on the first floor for egress. We write every one of these into the initial written price so the permit review doesn’t surprise you. If the city asks for something extra at plan check, you’ll see it in writing before we proceed.

Contractor installing framing for a professional home addition project in Tarzana, CA

Trusted Brands We Service in Tarzana

We’re hands-on with the materials brands serious homeowners research before calling anyone: James Hardie siding and trim, and prefab building systems from Abodu, Cover, and Dvele. For Tarzana additions, James Hardie fiber cement makes particular sense because it holds up to the Valley’s 100 to 108 degree summer heat without warping like vinyl, and it carries the ignition-resistant rating hillside parcels need under Chapter 7A. We keep local supplier relationships in the San Fernando Valley, which means material lead times are shorter and mismatched trim doesn’t sit on order for six weeks while your family lives in a construction zone.

Common Home Addition Contractor Problems We See in Tarzana Homes

  • Hillside fire-zone surprises on southern-edge parcels. A lot half a mile south of your neighbor can trigger Chapter 7A requirements: Class A roofing, ember-resistant vents, and multi-pane glazing. If your first contractor bid ignores that, the budget blows up mid-permit.
  • Loaded 100-amp electrical panels from the original build. The 1952 to 1978 ranches that dominate Tarzana were wired for a different era. A room addition with a mini-split HVAC and new circuits almost always requires a 200-amp service upgrade, which is a permit-triggered cost many bids omit.
  • Failed stucco waterproofing and no weep screed. When we open walls on these ranches, we regularly find water has been migrating behind the stucco for decades because the original build lacked proper drainage detailing. The thermal swing between Tarzana’s hot days and cool nights accelerates cracking once new work meets old.
  • Termite and dry-rot damage at base plates. Raised foundations and decades of irrigation splash leave the bottom of exterior walls vulnerable. Repairing that before framing proceeds is structural, not optional, and it should be a written change order, not a verbal surprise.

Pricing for Home Addition Contractor in Tarzana, CA

A room addition in Tarzana typically runs $180 to $350 per square foot, and a second story runs $280 to $450 per square foot. The spread reflects what your lot and your existing structure demand: flat-lot parcels north of Ventura Boulevard sit at the lower end, while southern hillside parcels inside the Very High Fire Hazard Severity Zone can add $15,000 to $25,000 in Chapter 7A compliance costs alone. Every Tarzana job also needs to account for the electrical service upgrade: budgeting $4,000 to $8,000 for a 200-amp panel and sub-panel protects you from the most common mid-project surprise. We give you a written line-item price before any work begins, and change orders require your written approval before demo continues. Call (707) 383-5338 to schedule a free estimate and walkthrough with Ben.

We Also Serve Cities Near Tarzana

While this page focuses on Home Addition Contractor in Tarzana, our crews also work in Encino, Reseda, Woodland Hills, and Canoga Park. If your home sits just outside Tarzana’s borders, the same written pricing and Cedarwell Care Promise apply. Call us and we’ll confirm your lot’s specific conditions and give you a real number.

Serving Tarzana, CA - Our Local Coverage Area

We’re based in the Tarzana 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 Tarzana

Why Tarzana Chooses Seedling ADU Builders

We set the standard for home addition contractor in Tarzana.

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 Tarzana

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 Tarzana - 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 Tarzana Customers Say

Trusted by homeowners across Tarzana 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
★★★★★

"Added a backyard cottage. The team protected our existing landscaping and left the yard clean every evening. Gentle, respectful, and they walked us through each stage calmly."

Tamara Welsh · 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

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