Compare vetted, CSLB license-verified ADU builders and ADU contractors in Tarzana. The average cost to build an ADU in Tarzana is $280–$420 per square foot. Top-rated builders include Olympia Construction by Design, Quality First Builders, Acton ADU.
Every builder below is CSLB license-verified, bonded, and insured — vetted before they ever reach a homeowner. Browse ratings and real reviews, compare starting prices, or let us match you with the best fit for your lot and budget. It's free; we're paid by the builders, not you.
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Recent LADBS records show permit volume, project size, and valuation patterns for ADU work in Tarzana.
Trend: recent LADBS activity is running above earlier years, averaging 50 permits per year in 2025-2026 versus 39 per year in 2020-2024.
Source: LA Dept. of Building & Safety.
Last updated July 16, 2026

Serving Tarzana, CA · Encino, CA
“We recently completed a full home remodel in Sherman Oaks with Olympia Construction, and the experience was excellent from start to finish. We received five dif…”— Sapir Adani
Pricing on request
Licensed Los Angeles general contractor building custom ADUs across the San Fernando Valley

Serving Tarzana, CA · Sherman Oaks, CA
“Before we started I honestly thought a garage ADU would feel like exactly that... a garage that someone tried to dress up. That was my biggest concern because t…”— Vicente Enriquez
Pricing on request
Design-build ADUs, additions and remodels across Los Angeles and the San Fernando Valley.

Serving Tarzana, CA · Campbell, CA
“We had a great experience working with Acton ADU on our ADU project, and I want to give a special shoutout to Sandro. Sandro was fantastic from start to finish—…”— N K
Pricing on request
A California general building contractor licensed since 1992, serving the LA market statewide.

Serving Tarzana, CA · Canoga Park, CA
“Instead of replacing one thing at a time, we decided to do the bathroom remodel properly in one project. That choice saved us from having to redo the work later…”— Isaac Bailey
Pricing on request
Your Vision, Our Craft — transforming LA homes inside and out.

Serving Tarzana, CA · Los Angeles, CA
“We begun the first phase of our ADU project and so far the experience has been very positive. The team has been professional and organize throughout the demolit…”— Marcia Berry
Pricing on request
Trusted design-build ADU specialists for Los Angeles and surrounding communities.
Serving Tarzana, CA · Tarzana, CA
“ADU Concepts built a detached ADU on our Calabasas property and did a fantastic job. They guided us through permitting, construction, and inspections while keep…”— Michael Stoltzman
Pricing on request
CSLB-verified A | B contractor in Tarzana, CA.

Serving Tarzana, CA · San Francisco, CA
“Excellent job! The Villa crew from start to finish nothing short of professional. Foundation, home delivery, finish work etc top notch. I would recommend Vill…”— M Ferreira
Pricing on request
Tech-enabled prefab ADU builder delivering turnkey backyard homes across California.

Serving Tarzana, CA · Mill Valley, CA
“Nestadu did a great job on my backyard ADU. Their team was professional, and the final result looks fantastic—well-built and blends in nicely with my home. Pric…”— Stephen Reid
Pricing on request
Custom and prefab ADUs for California homeowners — design, permit, and build, turnkey.

Serving Tarzana, CA · Encino, CA
“Now that my ADU is complete, I can confidently say it has exceeded my expectations. The quality of craftsmanship is impressive, and I’m excited about the potent…”— TOM MERLIN
Pricing on request
Family-owned ADU and garage-conversion builder serving Encino, Woodland Hills & the San Fernando Valley.
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Building an ADU in Tarzana runs roughly $280–$420 per square foot all-in. Here's how the city benchmarks against the broader metro and statewide averages.
| Area | Avg. cost / sq ft | Typical 800 sq ft ADU |
|---|---|---|
| Tarzana | $280–$420 | $224,000–$336,000 |
| Tarzana metro | ~$350 | ~$280,000 |
| California (CA) | ~$330 | ~$264,000 |
| ADU type | Typical size | Project cost | Timeline |
|---|---|---|---|
| Detached ADU | 600–1,200 sq ft | $180,000–$420,000 | 8–12 months |
| Attached ADU | 400–800 sq ft | $140,000–$300,000 | 6–10 months |
| Garage Conversion | 400–600 sq ft | $90,000–$180,000 | 4–7 months |
| JADU (Junior ADU) | ≤ 500 sq ft | $60,000–$140,000 | 3–6 months |
Tarzana ADU permits are handled through LADBS under California's 60-day ministerial review rules for compliant ADUs. Confirm lot-specific setbacks, height, parking, and utility details before submitting plans.
| Jurisdiction | Permit timeline | Permit fees | Notes |
|---|---|---|---|
| City of Los Angeles | 60-day plan check (by law) | $3k–$8k | Pre-approved Standard Plan program available |
| Unincorporated LA County | 60–90 days | $4k–$10k | Ministerial approval for compliant ADUs |
| Statewide (CA) | 60 days max by statute | Varies | Owner-occupancy requirement waived through 2030 |
Most Tarzana homeowners compare renovation loans, construction loans, HELOCs, and cash-out refinancing. ADU-focused lenders can underwrite against after-build value when the new unit materially increases rent or resale potential.
Construction / renovation loan
Funds released in draws as the build hits milestones; underwritten against after-build value.
HELOC / home equity
Borrow against existing equity. Fast to set up if you have 20%+ equity.
Cash-out refinance
Replace your mortgage and pull equity as cash — best when rates are favorable.
ADU-specific lenders
RenoFi and similar lenders underwrite the projected value the ADU adds, often unlocking more.