A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable ADU Builders Across Tarzana
ADU construction in Tarzana runs $180,000 to $420,000 for a detached unit, with garage conversions landing between $95,000 and $160,000 before permit fees. Most Tarzana projects take 6 to 14 months from first drawings to final inspection, depending on whether your lot sits north or south of Ventura Blvd and what the soils report says. Our crews work across Tarzana every week, and we know which hillside lots trigger extra grading requirements before we even walk the property. Call (559) 254-0116 and Reed Calloway will walk you through what your specific lot needs.
We are ADU Builders who put the price in writing before any work starts. That matters in Tarzana, where the difference between a flatland lot and a hillside lot can change your foundation cost by $15,000 or more. You will know the number on day one, and it will not move on the final invoice.
Why Fielding ADU Woodland Hills Is Tarzana’s Preferred ADU Builders Company
Tarzana homeowners have dealt with enough contractors who show up late, move the price, or leave the permit board blank. We operate differently because we have to. Fielding ADU Builders is an independently owned member of the Garrison Partners family, held to The Garrison Standard since 2006: show up in the window, put the price in writing, build by the book, leave it clean, and stand behind the work for a full year.
The 365-Day Done Right Promise is not marketing language. Every ADU we build in Tarzana is covered in writing for one full year. If something fails inside that year, we return at no charge and correct the defect. That guarantee is spelled out on paper before we start: what it covers, how long it runs, and exactly how we make it right.
Background-checked, uniformed crews arrive on every Tarzana job. You know who is on your property, and you can reach a live person any hour of the day or night. No voicemail, no callback queue.
JADU in Tarzana
JADU work in Tarzana means converting existing space inside your home, attached garage, or an existing accessory structure into a self-contained junior accessory dwelling unit, typically running $70,000 to $130,000 depending on whether you need a new kitchenette, bathroom, and a separate entrance. A JADU cannot exceed 500 square feet under California law, and in Tarzana it is often the fastest path to rental income because it does not require the same setback, grading, or drainage reviews that a detached unit triggers. For a 1950s ranch on Corbin Avenue or a larger property off Wilbur Avenue, a JADU usually moves through permitting in 3 to 5 months.
Attached Garage Conversions
Converting an attached garage into a JADU in Tarzana means working with the existing slab, which on many homes south of Ventura Blvd sits on expansive clay. We test the slab before we commit to a design. If the slab is sound, you save real money; if it has moved, we isolate the new living space from the old foundation so the JADU does not inherit the house’s cracks.
Interior Space Conversions
When a Tarzana homeowner has a large den or unused bedroom wing, a JADU can be carved out of the existing footprint. The work involves adding a kitchenette with a small appliance line, a bathroom, and in most cases a separate exterior door. Because no new foundation is poured, this is the least expensive way to add a legal rental unit in Tarzana, and it avoids the hillside drainage review entirely on most flat lots.
ADU Plans in Tarzana
ADU Plans in Tarzana are the permit-ready drawing sets, structural calculations, and site plans that LA County requires before you can pull a building permit, typically running $4,500 to $9,500 depending on whether your lot is flat or subject to hillside review. For properties north of Ventura Blvd, the plan set must include grading and drainage drawings, retaining wall details if the slope exceeds certain thresholds, and wind-load calculations for roof tie-downs. A flat lot south of the Blvd still needs a soils report if the existing home shows slab cracks, which is common on the clay-heavy ground between Tampa Avenue and Reseda Blvd.
Permit-Ready Drawing Sets
We produce drawing sets that Tarzana’s reviewers accept the first time. That means title-24 energy calculations, structural engineering stamps, and foundation details sized for your specific soil conditions. We pull the permits ourselves and schedule the inspections, so you are not chasing paperwork across county offices.
Site and Grading Plans
For sloped Tarzana lots, the grading plan is the document that makes or breaks the project. LA County’s Hillside Ordinance requires engineered drainage that keeps runoff on your property and away from your neighbor’s foundation. We design these plans up front, not after the excavator hits rock and the inspector issues a stop-work order.
Trusted Brands We Service in Tarzana
We work with the ADU platforms Tarzana homeowners are already researching: Abodu and Cover for prefab detached units, Mighty Buildings for panelized construction, and Tuff Shed-style structures for simple studio conversions. For conventional builds, we use James Hardie siding because it handles Tarzana’s hot, dry summers without warping and meets the wind-driven debris ratings that Santa Ana season demands. We stock the common connection hardware and hold-downs for these systems locally, which means we are not waiting on a distributor when your framing inspection is scheduled. We also service and complete ADUs originally ordered through Boxabl and Plant Prefab, matching their panel tolerances to a foundation built for Tarzana soil.
Common ADU Builders Problems We See in Tarzana Homes
- Roof tie-downs that fail wind-load review. Santa Ana winds hit Tarzana hard, and LA County requires specific uplift ratings for ADU roofs. Cheap quotes skip the hold-down hardware and the stamped engineering, then the framing inspection fails and the retrofit costs more than doing it right the first time.
- Slab cracks on clay soil south of Ventura Blvd. The expansive clay between Tampa and Reseda moves with every wet winter. Standard footings poured without a soils report crack within the first rainy season, and the ADU inherits the problem.
- Stop-work orders on hillside lots north of the Blvd. Skipping the grading and drainage plan on a sloped Tarzana lot triggers a stop-work order fast. The county requires the drainage design before excavation, and a retroactive retaining wall after the fact costs two to three times what a planned wall costs.
- Prefab units placed on undersized foundations. We have corrected Boxabl and Mighty Buildings installations where the original contractor poured a generic slab without accounting for Tarzana’s soil expansion. The units met spec; the foundations did not.
Pricing for ADU Builders in Tarzana, CA
A detached ADU in Tarzana runs $180,000 to $420,000. Garage conversions run $95,000 to $160,000. A JADU runs $70,000 to $130,000. Plans alone run $4,500 to $9,500. The biggest cost swings come from foundation work: a flat lot with good soil needs standard footings, while a hillside lot north of Ventura Blvd or clay-heavy ground south of it can add $15,000 to $30,000 in piers, drainage, and retaining systems. Permits in Tarzana typically run $8,000 to $18,000 depending on project value and hillside review triggers. Call (559) 254-0116 and Reed Calloway will give you a written price before any work starts. The estimate is free.
We Also Serve Cities Near Tarzana
Our crews cover the neighborhoods around Tarzana as well. We build ADUs in Tarzana, and we regularly work in Encino, Reseda, Woodland Hills, and Winnetka. If your lot sits near the Tarzana border, the same crew and the same written-price policy apply.
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 Builders in Tarzana
Tarzana ADUs must meet an ultimate wind speed rating of 89 to 105 mph depending on exact site exposure, with continuous load-path hold-downs from roof to foundation. James Hardie siding, Simpson Strong-Tie connectors, and properly spec’d pre-engineered trusses all carry ratings that satisfy LA County reviewers. A cheap quote that omits the stamped wind-load calculation will fail framing inspection. Call (559) 254-0116 and we’ll show you the specific products your plan set needs.
For ADU plans in Tarzana, a soils report is not automatically required for a flat lot, but LA County can require one if the existing home shows slab cracks or if you are building over 750 square feet on clay-heavy ground south of Ventura Blvd. Many Tarzana lots in the flatlands have expansive clay documented in county geotechnical surveys. We recommend a soils test on any Tarzana flat lot where the original 1950s slab has visible movement; the test costs roughly $2,000 and can save $25,000 in foundation repairs later. Call
Documented compliance gives your insurer written proof that the ADU meets current wind and drainage codes, which can prevent premium increases and speed up claims processing after Santa Ana wind events or heavy rain seasons. Insurers increasingly ask for the stamped engineering and passed inspection records when you add a rental unit to your policy. Our paper trail includes every permit, every inspection sign-off, and the final certificate of occupancy. Call (559) 254-0116 to discuss how we document your build.
Hillside ADUs north of Ventura Blvd require grading and drainage inspections, retaining wall inspections if the slope exceeds specific thresholds, and a soils compaction report before the foundation pour. LA County’s Hillside Ordinance also triggers a geology review in some Tarzana hillside zones. Expect two to three additional inspection visits compared to a flatland build, adding roughly 4 to 8 weeks to the timeline. Our crews schedule these inspections as part of the build, so you are not chasing the county yourself. Call (559) 254-0116 for a timeline specific to your lot.
Yes, but only when the foundation is engineered for Tarzana’s soil and wind uplift ratings, and the panel connections are installed to the manufacturer’s seismic spec. We have installed and serviced both Boxabl and Mighty Buildings units in Tarzana. The unit itself carries the wind rating; the foundation and anchoring system is where cheap installs fail. We engineer the piers, anchors, and drainage to match the specific unit’s loads. Call (559) 254-0116 and we’ll walk you through what a compliant prefab foundation costs in Tarzana.
Written by Reed Calloway, Owner at Fielding ADU Woodland Hills, serving Tarzana and the surrounding area.
Why Tarzana Chooses Fielding ADU Woodland Hills
We set the standard for adu builders 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 adu builders handled is simple and fast.
Call or Request a Free Estimate
Tell us about your adu builders needs and we provide an upfront, transparent quote - no obligation, no hidden fees.
Licensed Technician Dispatched
A background-checked, certified technician arrives in Tarzana - typically within 30-60 minutes, with parts stocked on the truck.
Problem Solved, Guaranteed
We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu builders 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
Trusted by homeowners across Tarzana and surrounding areas.
"Built a detached ADU behind our house. The builder is a veteran and runs the site like a platoon: schedule posted, crew on time, everything labeled. Finished within a few days of the date."
"Garage conversion with a new bath and kitchenette. Permit was handled by them. Inspection passed first time."
"Foundation and slab poured on schedule. Crew kept the yard orderly."
Our Work in Tarzana
A look at recent adu projects across Tarzana and surrounding areas.
More ADU services in Tarzana
Every build below starts the same way: a free site visit and a written price.
Room Addition Contractor
Room additions built to match the house, engineered, permitted and inspected.
Explore room addition contractorGarage Conversion Contractor
Garage conversions with insulation, windows, a raised floor, a kitchenette and a bathroom.
Explore garage conversion contractorGetting started with Fielding in Woodland Hills
Every project starts with a conversation and a written price. Here is how to take the first step.
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
Your Woodland Hills team
A local crew that works across Woodland Hills and the towns around it, to the same written standard as every Fielding location.
Areas we serve
Read our written promise
What we promise on every job, written down, with the terms spelled out before any work starts.
Our promiseReady for ADU Builders in Tarzana?
Call now for a free estimate - or request one below. Licensed, insured, and here with fast after-hours help in Tarzana.
(559) 254-0116Request a Free Estimate in Tarzana
Tell us about your adu builders needs - we'll respond within the hour.