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 Woodland Hills
Adding an ADU in Woodland Hills typically runs $230,000 – $410,000 for a detached unit and $180,000 – $320,000 for an attached conversion, with prefab options from Abodu, Cover, and Dvele landing on the lower end of that range. The biggest variable isn’t lumber or drywall. It’s what’s hiding behind the walls of a 1950s – 1970s ranch once we open them up. Our crews know Woodland Hills block by block, from the flat grid streets south of Ventura Boulevard to the winding hillside roads north of it, and we’ve learned exactly which questions to ask before your quote is written. Call (559) 282-2291 to get a written price before any work starts.
Why Benson ADU Woodland Hills Is Woodland Hills’s Preferred ADU Builders Company
Homeowners in Woodland Hills don’t have time for a contractor who disappears after the handshake. Our ADU Builders team shows up when we say we will, with a written scope in hand and a background-checked, uniformed crew. Every project follows The Relay Visibility Guarantee. That means a written price before work begins, real-time tracking through the build, and a 365-Day Done Right Promise in writing. If something isn’t right within a full year, we come back and fix it. No arguing, no restocking fees, no “that’s normal settling.”
We’re led by Troy Eastman, a builder who has spent enough time in Woodland Hills attics and crawlspaces to know that a 1963 Walnut Acres ranch hides different problems than a 1985 Warner Center stucco box. That local knowledge shapes every estimate we write. When you call us about an ADU Builders in Woodland Hills project, you’ll reach a live person, not a voicemail tree. That’s true at noon and at 2 a.m., every day of the year.
ADU Plans in Woodland Hills
ADU Plans in Woodland Hills aren’t just drawings. They’re the legal document that determines whether your project clears the 2003 Ventura Boulevard Specific Plan, meets fire-hardening requirements for the Santa Monica Mountains interface, and survives a hillside grading review without a redesign. Homeowners come to us when they’re just starting out with an idea, not when they’ve already committed to a floor plan. Good, because that’s when the right plan saves real money. In Woodland Hills, a full ADU plan set with Title 24 energy calculations, structural engineering, and permit-ready drawings runs $12,000 – $22,000 depending on whether you’re building flat-lot in Warner Center or cutting into a slope above Ventura Boulevard.
Detached Flat-Lot Plans
A flat lot south of Ventura Boulevard gives you the most predictable plan path in Woodland Hills. The Specific Plan caps floor area ratio at 0.50 for single-family parcels, so your ADU’s footprint gets checked against the main house, the garage, and any covered patios. We map that first, before we draw a single wall. Starting with the FAR math saves you the $6,000 – $9,000 redesign bill that hits when a roof ridge exceeds the cap mid-permit.
Hillside and Slope-Triggered Plans
North of Ventura, the roads curve and the lots tilt. A 15% slope triggers a hillside review in Woodland Hills even if your street feels flat. That review changes foundation type, drainage design, and sometimes the ADU’s placement entirely. Our plans include a geotech report recommendation and a preliminary grading plan, so the city reviewer sees a complete file the first time. That’s the difference between a 4-week permit review and a 14-week back-and-forth.
ADU Contractor in Woodland Hills
An ADU Contractor in Woodland Hills does more than swing a hammer. They manage the permit, the soils engineer, the Title 24 consultant, the gas and electrical service upgrade, and the inevitable surprise behind wall number three. When you’re spending six figures on a project, the person running it needs to know which Woodland Hills homes still have 60-amp panels and which slopes drain onto the neighbor’s yard. We do. A typical detached ADU construction contract in Woodland Hills runs $210,000 – $390,000, with site-built units landing higher and prefab installations from Cover or Dvele coming in around the middle.
Permit Management and Code Compliance
We pull permits under the project address, coordinate the inspections, and write any change order in plain English before a single dollar moves. Woodland Hills code enforcement is responsive, not aggressive, but they will flag a project that skips the Specific Plan review. We file correctly the first time because we’ve done this enough times to know exactly what triggers a reviewer’s attention. One less delay is one less month of carrying costs on a project you’re not renting out yet.
Warranty and Post-Build Support
Every project carries a written guarantee and a free second visit if any covered repair fails. The 365-Day Done Right Promise isn’t a verbal pat on the back. It’s stamped on the contract. If a door binds, a mini-split throws a code, or a seam opens in the Hardie siding, we’re back in Woodland Hills to make it right. You’re never chasing a subcontractor’s subcontractor.
Trusted Brands We Service in Woodland Hills
We’re authorized to build with brands you can research before you ever sign a contract: Abodu, Cover, Dvele, and James Hardie cladding. That matters in Woodland Hills because prefab panel systems from Abodu and Dvele cut on-site framing time by weeks, which means fewer days where your lot is exposed to 105°F heat or Santa Ana wind. James Hardie fiber cement holds up in this climate better than wood lap siding, especially in the hillside zones where wildfire risk is real. We stock common hardware and panel components for Woodland Hills installations, so warranty work and adjustments don’t wait on a container ship.
Common ADU Builders Problems We See in Woodland Hills Homes
- Knob-and-tube wiring still live in the walls. Homes built between 1950 and 1970 often have original cloth-insulated wiring that was never fully replaced. Adding an ADU triggers a Title 24 electrical review, which means that wiring must come out before we close the drywall. We price this as a known risk, not an after-invoice surprise.
- Rotted sill plates from old planter beds. The classic 1960s Woodland Hills ranch had flower beds built right against the exterior wall. Fifty years of trapped moisture rots the mudsill and sometimes the bottom foot of studs. We find this so often on Walnut Acres and Woodland Hills proper that we include a sill-plate inspection line in every remodel quote.
- Undersized 60-amp electrical panels. Your original panel wasn’t designed for a heat-pump water heater, a mini-split, and an induction cooktop all drawing at once. On a 105°F afternoon in the San Fernando Valley, a 60-amp panel trips. Every ADU we build includes a service upgrade calculation, and we show you the actual number in writing before we start.
- Ancient fill under flat Warner Center lots. Builders in the 1960s often flattened Warner Center parcels with loose fill and construction debris. A standard slab-on-grade foundation can crack on that material. We recommend a soils report on every flat-lot ADU in Woodland Hills, even when the city doesn’t require one. Skipping it is how a $28,000 foundation line item becomes $61,000 after excavation reveals the truth.
Pricing for ADU Builders in Woodland Hills, CA
Here’s what we tell every homeowner before they commit: a detached studio ADU in Woodland Hills runs $230,000 – $310,000. A one-bedroom detached unit runs $280,000 – $410,000. An attached conversion of an existing garage runs $180,000 – $260,000. Prefab installations from Abodu or Dvele typically land 12 – 18% below site-built framing on the same lot. The wildcard is existing conditions: panel capacity, sill-plate rot, hillside grading, and soils. We write those as line-item allowances in your contract, with a written change order for anything that exceeds the allowance. You approve the price before the work happens. Call (559) 282-2291 to get your written estimate started.
We Also Serve Cities Near Woodland Hills
Our crews build ADUs across the west San Fernando Valley, including Canoga Park, Topanga, Tarzana, and West Hills. The opportunity to serve your block is never more than a short drive from our Woodland Hills job sites, and our scheduling team coordinates directly with each city’s building department.
Serving Woodland Hills, CA - Our Local Coverage Area
We’re based in the Woodland Hills 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 Woodland Hills
Yes, it does. South of Ventura Boulevard, single-family residential parcels in Woodland Hills carry a 0.50 floor area ratio cap. Your ADU’s square footage, plus the main house, plus any garage or covered patio, cannot exceed half your lot’s total square footage. A 7,500 square foot lot means 3,750 square feet of total floor area across every structure. We run that math on day one. If your proposed ADU pushes you past 0.50, we’ll walk you through options including a smaller footprint, a JADU conversion instead of a detached unit, or a setback variance petition. Call (559) 282-2291 and we’ll run your lot’s numbers before you pay for anything.
The city’s hillside trigger in Woodland Hills isn’t about the street, it’s about the parcel’s natural slope before any grading. A 15% or greater slope anywhere on the lot, even in a corner nearest the hillside, can trigger a hillside review under the Specific Plan. If your neighbor’s lot slopes away from yours, the reviewer may still pull the trigger. The fix isn’t a redesign, it’s a geotech report and a grading plan submitted with the first permit application. We’ve navigated dozens of these reviews, and a complete file submitted upfront almost always moves faster than a partial one. Get a written assessment from our team before you buy plans.
Expect to find knob-and-tube or early Romex wiring that hasn’t been touched since Lyndon Johnson was president, plus corroded connections at the panel. On a Walnut Acres ranch built in 1963, our crew found knob-and-tube wiring still live in the wall we opened for an attached ADU, along with a rotted sill plate where an old planter bed had trapped water against the studs. We rewired to current Title 24, poured a new stem-wall footing for the added square footage, and wrote the $8,400 waterproofing upgrade into the change order, approved before we moved a single 2×4. A full rewire of a 1,200 square foot Woodland Hills ranch runs $14,000 – $24,000 depending on how much of the original wire is still in the walls. We include a rewiring allowance in every attached ADU quote, not a vague “we’ll see what we find” line. Call (559) 282-2291 for an exact figure once we inspect your panel and attic.
Most of the time, yes. Title 24 energy standards require each dwelling unit to be independently conditioned, and you can’t simply tap the main house’s ductwork because ADUs need their own thermostatic control and their own energy compliance path. In Woodland Hills, where summer afternoons regularly cross 100°F, a ductless mini-split sized for the ADU’s square footage and orientation is the standard move. We size them for the hottest week in August, not the average. That means a 9,000 BTU unit for a 400 square foot studio, and 12,000 – 18,000 BTU for a one-bedroom with west-facing windows. Expect $4,800 – $9,600 for a complete mini-split system installed in an ADU here, including the electrical circuit.
Probably not, and this is exactly where online plan services fail Woodland Hills homeowners. A standard slab assumes level, undisturbed soil. A hillside lot in Woodland Hills almost always needs a stepped footing, a stem wall, or piers, and sometimes all three, depending on the slope and the soil’s shear strength. If you’re north of Ventura Boulevard, plan for a foundation that runs 30 – 50% more than a flat-lot slab. On a modest slope, that means $32,000 – $48,000 instead of $22,000. On a steep slope, more. We make the soil report part of the design process, not a surprise after demo. Call (559) 282-2291 for a free foundation assessment based on your actual parcel, not a generic plan set.
Ready to start? Call (559) 282-2291 or use the contact form on this page to schedule your free estimate. We will put your project’s numbers in writing before you commit to anything.
Written by Troy Eastman, Owner at Benson ADU Woodland Hills, serving Woodland Hills and the west San Fernando Valley.
