A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Tarzana, CA
Adding an ADU in Tarzana means working with generous lot sizes and ranch-era homes that have real potential, but also navigating hillside setback rules and aging utility lines that can quietly add cost. Benson ADU Woodland Hills builds accessory dwelling units, home additions, and room additions across Tarzana with a written price before any work starts, so you’re never guessing what the final number will be. If you’re weighing a detached unit in the flats or a hillside build south of Ventura Boulevard, call (559) 282-2291 and we’ll walk you through what’s realistic for your specific lot.
Why Tarzana Homes Are Different
Tarzana’s housing stock skews heavily toward 1950s through 1970s ranch homes on lots that are wider and deeper than what you’ll find in Sherman Oaks or Studio City. That’s good news for ADU feasibility because setbacks become easier to meet when you have room to work with. The tradeoff is age. Many of these properties still run on original electrical panels, cast-iron drain lines, and footings that predate current seismic standards, which means a straightforward ADU sometimes requires foundation or utility upgrades before the first prefab panel arrives.
The other factor is terrain. South of Ventura Boulevard, the streets climb into the Santa Monica Mountains and the lots become steeper, with expansive soil that shifts through wet-dry cycles. ADU projects in this zone frequently need grading plans and retaining walls, and those add permitting time and cost. North of the Boulevard tends to be flatter and more predictable, though mature oak trees and protected root zones can still limit where a unit can sit. Either way, Tarzana ADU work rewards early site planning more than most neighborhoods in the Valley.
Climate matters too. Tarzana gets hot, dry summers and occasional Santa Ana wind events that push embers through hillside neighborhoods. We specify insulation levels, cooling capacity, and fire-resistant siding choices, including James Hardie cladding, with that local weather reality in mind. You should not have to think about any of this when you’re picturing your in-laws suite or rental unit. That’s our job.
Our Main Tarzana Services
Tarzana homeowners usually reach out to us for one of two reasons: they want a detached ADU in the backyard, or they want to add square footage directly onto the existing house. Here’s how each works in Tarzana specifically.
ADU Builders in Tarzana
A detached ADU in Tarzana gives you a fully separate unit with its own entrance, kitchen, and bath, built in your rear yard. On Tarzana’s wider lots, that usually means a 600 to 1,000 square foot structure set back from the main house. The wrinkle comes with older properties where the sewer lateral or electrical service needs upgrading to support a second dwelling, and with hillside sites where grading and retaining walls enter the picture. Troy Eastman and our team pull the permits, manage the site work, and build with prefab brands like Abodu and Cover when they fit the lot, or stick-build where the terrain demands it. Read more on ADU Builders in Tarzana.
Home Addition Contractor in Tarzana
A home addition in Tarzana extends your existing footprint, usually for a larger kitchen, a primary suite, or a family room that finally fits everyone. Because so many Tarzana homes are single-story ranches, additions often mean going out rather than up, which keeps engineering simpler but still triggers foundation, roof-tie-in, and HVAC work. We handle the full permit set and coordinate trades so the addition connects to the existing house cleanly, matching rooflines and stucco texture where it matters. See Home Addition Contractor in Tarzana for the details.
Room Addition Contractor in Tarzana
A room addition is the smaller cousin, typically one bedroom, a home office, or a playroom added onto the back or side of the house. In Tarzana that’s often 200 to 400 square feet, and the biggest variable is whether the existing slab can carry the load or whether we’re pouring new footings. Older homes sometimes have slabs without rebar and with shallow perimeter edges, which means more concrete work than a newer build would need. We’ll walk you through that before you sign anything. Learn more on Room Addition Contractor in Tarzana.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Tarzana
We build with prefab systems from Abodu and Cover, plus Dvele for high-performance homes, and we source James Hardie siding for fire-resistant exteriors across Tarzana. These are brands you can research independently, and you’ll see them specified directly on your written proposal. Our brands page explains what makes each system worth considering for a Valley lot.
Pricing for ADU Company in Tarzana, CA
Here’s what Tarzana homeowners can expect to pay for a full ADU home project with permits, site work, and finishes, based on current local build costs. These are line-item ranges, not guesses, and you’ll see the exact number before any work begins.
| Service | Typical Range in Tarzana |
|---|---|
| Detached ADU (600 sq ft, prefab, standard lot) | $180,000 – $240,000 |
| Detached ADU (800 – 1,000 sq ft, site-built, hillside) | $300,000 – $420,000 |
| Detached ADU (1,000+ sq ft, custom, hillside with retaining walls) | $450,000 – $620,000 |
| JADU conversion (interior garage, 300 – 500 sq ft) | $90,000 – $150,000 |
| Garage conversion to ADU (detached, 400 – 600 sq ft) | $130,000 – $200,000 |
| Full home addition (400 – 800 sq ft, single-story ranch) | $160,000 – $290,000 |
| Full home addition (800 – 1,200 sq ft, second story) | $280,000 – $450,000 |
| Room addition (200 – 400 sq ft, bedroom or office) | $70,000 – $130,000 |
| Room addition (400 – 600 sq ft, primary suite) | $120,000 – $210,000 |
| Foundation upgrade (older ranch, seismic retrofit) | $25,000 – $60,000 |
| Electrical panel upgrade (200A service) | $3,500 – $7,000 |
| Grading and retaining wall (hillside lot) | $20,000 – $80,000 |
The two things that push Tarzana prices up most are hillside conditions south of Ventura Boulevard and age-related utility or foundation upgrades on 1960s and 1970s homes. You’ll know exactly which of these apply to your lot before we start, because the price we give you in writing is the price you pay, no change orders for things we should have seen coming.
Neighborhoods We Serve in Tarzana
We cover the full Tarzana area, from the flats north of the Boulevard up into the hills where lots get steeper and setbacks get tighter. We typically have a crew in Tarzana on a weekly basis, though hillside jobs get scheduled around grading and inspection windows rather than a single drop-in visit.
- Tarzana Hills (south of Ventura Boulevard)
- Melody Acres
- Reseda Ranch adjacent streets
- Tampa Avenue corridor
- Oxnard Street flats
Service Area – Cities Near Tarzana
If you’re just outside Tarzana, we also handle ADU and addition work in Encino, CA, Reseda, CA, Woodland Hills, CA, and Winnetka, CA. The same written-price approach applies in every one of those cities. Call and we’ll let you know which crew covers your block.
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 ADU Company in Tarzana
Yes. Hillside ADUs in Tarzana often require grading plans, retaining wall permits, and geotechnical review before building can start. We coordinate all of that as part of the project, and your written price includes the permitting work. Call (559) 282-2291 and we’ll tell you what your specific lot is likely to trigger.
A standard detached ADU on a flat Tarzana lot typically runs 6 to 10 months from permit submittal to final inspection. Hillside projects with grading and retaining walls can add 3 to 6 months. You’ll get a schedule in writing at contract, and we update it as inspections pass.
Yes. Some Tarzana neighborhoods, especially newer Mediterranean-style developments, have HOAs with architectural review requirements. We prepare the submittal drawings and coordinate with the board so the design gets approved before you’re committed to construction.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Tarzana Customers Say
"Room addition off the kitchen. Framing, drywall, and paint all done well."
- Wade L."Fixed quote and clear change orders approved by text."
- Trina M."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N.
