Designing, permitting, and building detached ADUs, garage conversions, and Junior ADUs for Tarzana and Tarzana Hills homeowners. Office on Ventura Blvd. CSLB License #972213.
Hillstar Construction is a licensed Tarzana ADU contractor. Our office sits on Ventura Boulevard a short drive west of central Tarzana — which means a real person is on your property for the first site visit, not a sales representative passing through from across the county. We work with homeowners across Tarzana, Tarzana Hills, Braemar, Caballero Canyon, and the Mulholland-facing estate blocks on detached ADUs, garage-conversion ADUs, above-garage units, and Junior ADUs (JADUs) — each one shaped around the zoning, lot size, hillside status, and architectural context of the specific property.
Every project starts with a free on-site consultation, a clear written scope, and a straight answer about what your lot can actually support.
★★★★★ 5.0 · 17 reviews on Houzz
Tarzana runs larger on lot size than most Valley neighborhoods. South of Ventura Boulevard the flat R1 grid typically gives you 7,000 to 10,000 square feet of parcel to work with, and the hillside north of Ventura climbs into RE-zoned estate terrain with 15,000 to 40,000 square-foot lots up through Tarzana Hills and the Mulholland-facing slopes. Braemar — the gated community south of Ventura — layers an active HOA architectural review on top of the city permit process, and the Caballero Canyon hillside adds slope, grading, and access considerations most flat Valley neighborhoods never face.
A contractor who builds the same ADU regardless of lot condition tends to fight plan check, fight neighbors, or fight both. We design for your lot's actual zoning, slope, access, and HOA context first — because that's what makes the project go through the city cleanly and sit well on the block.
For homeowners still weighing an ADU against a main-home expansion, our home addition option is sometimes the better fit when the yard is already committed to pool, orchard, or mature landscaping that the family wants to keep intact.
ADUs in Tarzana are governed by California state law and Los Angeles city rules — the same framework that applies across the City of LA. The baseline rules below are what virtually every Tarzana property starts with. The specific envelope you get depends on zoning, hillside status, and any HOA or CC&R overlay that applies to your block.
Tarzana is a mix of R1 (5,000 sq ft minimum lot) and RE variants — RE9, RE11, RE15, RE20, and RE40 — with the RE concentration heaviest in the hillside north of Ventura Boulevard and scattered through the south-of-Ventura flats. Most flat Tarzana R1 lots run 7,000 to 10,000 square feet, and hillside RE lots can reach 15,000 square feet and well beyond. Larger lot size generally translates to more usable ADU envelope before setbacks, pool, and landscaping constraints start to bite.
State law requires Los Angeles to allow a detached ADU of at least 850 square feet for a studio or one-bedroom, or at least 1,000 square feet for two or more bedrooms. LA permits detached ADUs up to 1,200 square feet. On most Tarzana R1 and RE lots the full 1,200 square feet is comfortably achievable with room for landscaping, setback buffers, and separate ADU yard access.
State law limits required side and rear setbacks to no more than four feet for a new detached or attached ADU. No setback is required where you convert an existing garage within its existing footprint — a common Tarzana path on older ranch and mid-century properties with substantial detached garages.
No new or replacement parking is required for an ADU on any lot within a half-mile walking distance of public transit. The Ventura Boulevard corridor through Tarzana — from Reseda Boulevard on the east past Providence Cedars-Sinai Tarzana Medical Center and along to Corbin Avenue — carries Metro Bus coverage and meets that threshold, which brings most flat Tarzana lots inside the buffer. Hillside lots farther up may fall outside the radius; where parking is required, one space per unit or bedroom applies and tandem parking on the existing driveway counts.
State law requires the city to determine whether your ADU application is complete within 15 business days and to approve or deny a complete application within 60 days. LADBS processes Tarzana ADU applications through the same Valley branch that handles Encino and Woodland Hills projects. Hillside lots, Braemar HOA architectural review, and utility-upgrade work all add calendar time on top of the baseline permit clock.
Tarzana Hills, Caballero Canyon, and the Mulholland-facing slopes sit within the LA Baseline Hillside Ordinance area. Hillside-designated lots are subject to additional height, grading, cut/fill, and export-dirt standards, and slope drives foundation engineering cost. Our Los Angeles permit guide walks through the broader permit flow in more detail.
Tarzana's split between larger flat R1 parcels, RE estate lots, and sloped hillside blocks means no single ADU configuration fits every property. Here's how we actually match ADU type to lot conditions in the neighborhood:
By far the most common Tarzana configuration, and usually the right call on the larger R1 and RE-zoned parcels with flat rear-yard buildable area. A freestanding 800 to 1,200 square-foot ADU offers the most design flexibility, the highest long-term value, and the cleanest separation between main home and secondary unit. Many Tarzana families build detached ADUs for returning adult children, aging parents, long-term guest accommodations, or dedicated work-from-home space rather than strictly for rental income.
Works well on older Tarzana properties with substantial detached garages that aren't serving much day-to-day purpose. State law allows garage-to-ADU conversions with no required setback from the existing footprint, which makes them among the fastest ADU types to permit. We check for structural issues, foundation condition, and drainage before committing to a conversion path — older single-wall-framed garages sometimes need more reinforcement than the permit drawings initially suggest.
Useful on tighter flat lots where rear-yard ground area is already spoken for by pool, landscaping, or setback constraints. Los Angeles allows ADUs above a garage with setbacks of no more than five feet from side and rear lot lines. Less common in Tarzana than in denser eastern Valley neighborhoods because most Tarzana lots have room for detached at-grade construction, but a valid fit on specific tight-yard parcels.
Tarzana Hills, Caballero Canyon, and Mulholland-facing lots often support a detached ADU, but the engineering side matters more than on flat parcels. Caissons or spread footings sized to slope, adequate access for concrete trucks and crane placement on narrow hillside streets, and drainage to protect both the main home and anything downhill — these are the details that separate hillside ADUs that actually get built from hillside ADUs that stall in plan check.
A JADU is carved out of the existing primary home — up to 500 square feet — and fits best when a detached ADU isn't realistic or the homeowner only needs a small additional unit. JADUs continue to have owner-occupancy requirements under state law. Often paired with a broader home remodeling project when the main Tarzana mid-century or ranch home is already being reworked into a contemporary update.
A realistic Tarzana ADU timeline from first site visit to certificate of occupancy is roughly 6 to 12 months. Permits move on the state-mandated 15-day / 60-day schedule when plans are submitted correctly; hillside lots in Tarzana Hills or Caballero Canyon, Braemar HOA review, and lots requiring utility upgrades add time. Construction itself runs 3 to 6 months for most detached builds once ground is broken.
Tarzana's buyer profile skews toward higher finish levels than the average LA ADU — hardwood floors, stone counters, higher-spec cabinetry, and architectural details that tie into a remodeled or updated mid-century or ranch main home. That raises cost per square foot compared to a base-spec build, especially in Braemar and the Mulholland-facing hillside where estate-level finishes are the norm. Our cost and ROI guide for building an ADU in Los Angeles breaks down the numbers and the variables that move them the most.
What we commit to on every Tarzana project: a written scope, a clear price, no surprise change orders unless construction uncovers something that genuinely requires one, and direct access to your project manager from kickoff through final walkthrough. The full ADU construction process is covered step-by-step in our construction guide.
Working on a neighboring project and want to compare notes? See our Encino ADU page and Woodland Hills ADU page for the same framework applied to adjacent neighborhoods.
Lior was such a pleasure to work with for our guest house remodel. He was so easy to get in touch with, incredibly responsive and finished the job early.
— Amy Christine, February 2019Lior is very personable and has many decades of construction experience. We appreciated his sincere evaluation of our project.
— Ann Anterasian, April 2019Tarzana runs heavier on larger parcels than most of the central Valley, which is the main thing that shapes ADU design here. South of Ventura Boulevard you'll find flat R1 lots that typically run 7,000 to 10,000 square feet, with larger RE pockets scattered through. North of Ventura, Tarzana climbs into slope-designated RE terrain that routinely includes 15,000 to 40,000 square-foot estate lots. On R1 parcels of this size a full 1,200 square-foot detached ADU sits comfortably with setbacks, landscaping buffers, and separate ADU yard access. On RE hillside lots the design envelope is larger but foundation engineering becomes a much bigger portion of the budget than on flat lots.
Yes. The hillside areas in Tarzana — including Caballero Canyon, Tarzana Hills, and the Mulholland-facing slopes — sit within the LA Baseline Hillside Ordinance, which adds height, grading, cut/fill, and export-dirt rules on top of standard ADU requirements. Caisson or spread-footing foundations sized to slope and soil, access for concrete trucks on narrow hillside streets, and drainage planning to protect both the main home and anything downhill are the parts that separate hillside ADUs that break ground from ones that get stuck in plan check. We walk every hillside lot before quoting so the engineering and access cost are priced into the scope from day one.
Braemar is one of the few Tarzana neighborhoods with an active HOA and architectural review committee, and state law allows HOAs to enforce reasonable architectural and aesthetic standards even when they can't ban an ADU outright. That typically means Braemar's architectural committee will weigh in on siding, roofing, color palette, window proportions, and how the ADU reads from the street or the golf course. We have handled Braemar-style architectural-review submissions before and run the HOA track in parallel with the city permit so you only sign off on the design once. Outside Braemar and a few small gated streets, most of Tarzana has no HOA and the only design gatekeeper is the city.
Yes. Tarzana has one of the stronger mid-century modern inventories in the west San Fernando Valley — single-story homes with low-slung rooflines, clerestory windows, post-and-beam framing, and warm wood and stone accents — alongside ranch, Spanish Colonial Revival, and a growing modern/contemporary custom wave in the hillside and Braemar areas. A well-designed detached ADU echoes the main home: matching roof pitch and eave detail for mid-century, clean stucco with clay tile for Spanish, and clean-line massing with matching siding for contemporary. We photograph the primary home on day one and carry those details into the ADU so the finished result reads as intentional rather than grafted on.
State law removes any ADU parking requirement for lots within a half-mile walking distance of public transit. The Ventura Boulevard corridor through Tarzana — from Reseda Boulevard on the east past Providence Cedars-Sinai Tarzana Medical Center and along to Corbin Avenue — carries Metro Bus coverage, which puts most flat Tarzana lots south of Ventura inside the buffer. Hillside lots north of Ventura and estate properties farther up the slope may fall outside the radius; where parking is required, one space per unit or bedroom applies and tandem parking on the existing driveway counts. We confirm each Tarzana address against the LADBS transit map at the first site visit.
Yes, and on Tarzana's larger lots it's a natural fit. Many original mid-century and ranch homes are being updated by second-generation owners — kitchen reworked, walls opened, primary suite expanded — and the same project often adds a detached ADU at the rear of the lot or converts a long-unused detached garage. Running the main-home remodel and the ADU as a single coordinated project lets one crew sequence both builds, consolidates permit coordination, and typically finishes both faster than running them back-to-back. See our home remodeling page for the broader scope of that kind of bundled Tarzana project.
