







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Woodland Hills
Home additions in Woodland Hills run anywhere from $90,000 for a modest bump-out to $400,000+ for a full second story, with detached ADUs typically falling between $180,000 and $320,000 depending on site conditions. Those numbers reflect real topography, real permit paths, and real delivery logistics across the 91364 and 91367 ZIP codes. This page is for homeowners who want to understand exactly what drives those numbers before they commit. Call (559) 282-2291 and we’ll walk your lot with you, usually within a few days, and put a written price in your hands before any dirt moves.
We’re the Home Addition Contractor team at Benson ADU Woodland Hills. We know that a flat-lot property in Walnut Acres and a hillside lot off Mulholland Drive are two different projects, even if they share a ZIP code. We scope both the same way: by standing on the actual dirt, checking setbacks, septic and well clearances, access for concrete trucks, and grading. Then we write it all down.
Why Benson ADU Woodland Hills Is Woodland Hills’s Preferred Home Addition Contractor Company

Woodland Hills homeowners call us because we answer the phone. A live person picks up, every time, around the clock. You’re not leaving a voicemail and hoping someone calls back after the long weekend. Troy Eastman, who leads our Woodland Hills operation, has built our process around one rule: a written price before any work starts. That means you see the full scope, the material brands, the permit assumptions, and the labor cost on paper. If the county rejects something later, we eat the revision, not you.
Our Woodland Hills customers routinely mention three things in reviews. First, the crews show up in uniform and we text a photo of who’s arriving before they knock. Second, the price we quote is the price we build to, with no change orders slipped in after demo day. Third, the 365-Day Done Right Promise actually gets used. If something isn’t right within a full year, Benson ADU Woodland Hills makes it right, at our cost. That promise is written into every contract, stamped on every project summary, and backed by a free second visit if any covered repair fails.
Scheduling a site walk in Woodland Hills is usually possible within 48 hours. We dispatch from the brand’s Los Angeles office, and our crews live and work in the Valley. That local presence means we can get to properties near Warner Center, Walnut Acres, and the canyon roads north of the Boulevard without a half-day drive. When you call (559) 282-2291, the person who answers can usually tell you whether your lot is in the city purview or county overlay just by asking a few questions about your address and hillside status.
Second Story Addition Contractor in Woodland Hills
A Second Story Addition Contractor in Woodland Hills deals with realities that flat-land contractors in other parts of Los Angeles never see. Adding an upward floor on a 1960s ranch home means checking whether the existing foundation and first-floor framing can carry the added load, then deciding between stick-built framing or prefabricated panel systems from brands like Dvele or Abodu. On hillside lots, the structural engineering gets more involved: piers, grade beams, and sometimes shear wall retrofits on the lower level before a single upper-floor wall goes up.
In Woodland Hills, a second story addition typically costs $220,000 to $400,000 for a full upper level with two bedrooms and a bath. Partial second-story additions, like adding a primary suite above a garage, land between $150,000 and $250,000. These are real numbers from projects we’ve scoped across the 91364 and 91367 ZIP codes, not national averages scraped from a generic website.
Foundation And Load Path First
Before we quote a second story, we look at what’s underneath. Mid-century homes in Woodland Hills often sit on raised foundations or slab-on-grade, and neither was designed with a second floor in mind. On Walnut Acres lots, the fix may be simple: add a few piers and a steel beam. On a hillside parcel off a winding road, the answer may require full foundation evaluation and possibly new footings. We identify this during the pre-quote walk and price it explicitly, because the last thing you want is a framing crew discovering it at week six.
Framing, Siding, And Fire Code
Woodland Hills sits against the Santa Monica Mountains, and wildfire risk is real. Upper-story framing, eave details, and cladding choices are governed by the city’s fire zone requirements, which affect material costs. We build with James Hardie fiber-cement siding on nearly every second-story we do in the hillside zones, both for durability and code compliance. It costs more than vinyl, but it’s the right product for this area, and we put it in writing rather than surprising you with the upgrade later.
Garage Addition Contractors in Woodland Hills

Garage Addition Contractors in Woodland Hills do two distinct types of work: building a new attached garage as living space, or converting an existing garage while adding square footage adjacent to it. Many homeowners on south-of-Ventura lots have oversized two-car garages attached to 1950s ranch homes, and the smartest move is often a garage conversion paired with a bump-out that adds a full bath or laundry room. On larger canyon properties, we more often build detached garage additions as shops or storage, sometimes combined with an ADU above.
A garage conversion without plumbing in Woodland Hills typically runs $70,000 to $130,000. Adding a bathroom to that garage conversion pushes the number to $110,000 to $180,000. A new detached two-car garage with workshop space and electrical service starts around $120,000 and can exceed $200,000 on hillside lots where grading and retaining walls are required.
Septic And Well Setbacks Change Everything
Parts of Woodland Hills, especially larger lots in the canyon areas and along the northern edge, are not on city sewer. If your property has a septic system or well, county setback rules apply to any new structure. A detached garage or ADU must maintain specific clearances from the leach field and well head, and that distance directly affects where the building can sit. We check this before pricing, not after permitting. The spot you’ve mentally placed the garage may not be the spot the county will approve.
Delivery Logistics On Canyon Roads
Building materials don’t teleport to your lot. On Ventura Boulevard or streets like Topanga Canyon Boulevard, a full concrete truck can roll right up. On some of the winding canyon roads off Mulholland, concrete trucks need flagging, pump trucks need staging areas, and truss deliveries might arrive in smaller loads. Each of those adds cost and changes the schedule. We name those line items in the written quote, so you’re not the one discovering a $4,000 pump-truck surcharge when the concrete shows up.
Trusted Brands We Service in Woodland Hills
We’re authorized to build with prefab and modular systems from Abodu, Cover, and Dvele, and we install James Hardie cladding on nearly every addition and ADU we put up in the hillside fire zones. That matters because these brands are independently verifiable. You can research Dvele’s panel fabrication process, or Abodu’s California permitting track record, before you ever sign with us. We keep the conversation grounded: for a flat-lot Walnut Acres build, a panelized system might save weeks of framing time; for a hillside site, site-built is often the better fit. We walk you through the tradeoff in plain English, and the chosen brand goes into your written price.
Common Home Addition Contractor Problems We See in Woodland Hills Homes
- Assuming city of LA permits apply everywhere. Woodland Hills is in Los Angeles, but hillside and large-lot properties with septic systems often fall under county health department rules for setbacks and waste. Contractors who don’t know this file plans that get rejected, and that delay is yours to pay for. We check jurisdiction before we draw anything.
- Underestimating grading costs on hillside lots. A lot that slopes six feet from front to back needs slope stabilization, drainage swales, and sometimes retaining before foundation work can start. We’ve seen homeowners get “affordable” quotes from contractors who skipped grading entirely, then watched that number double mid-project. Ours is priced from the start.
- Quoting standard material delivery routes that don’t work here. Some canyon roads in 91364 and 91367 can’t take a full-size concrete truck or long truss trailer. Contractors who don’t know the roads quote standard delivery and eat schedule delays, which turn into rushed work and change orders. We plan staging and flagging for Woodland Hills canyon access in advance.
- Ignoring wildfire materials requirements until inspection day. Builders who don’t work the Santa Monica Mountains foothills may assume standard materials pass. Fire zone requirements in Woodland Hills hillside areas call for specific eave details, venting, and ignition-resistant siding. James Hardie fiber-cement is our standard in those zones, so inspections pass the first time.
Pricing for Home Addition Contractor in Woodland Hills, CA
Here’s the honest range for what people pay in Woodland Hills, based on project type. A bump-out addition of 200 to 400 square feet runs $90,000 to $180,000. A garage conversion without plumbing is $70,000 to $130,000; with a bathroom, $110,000 to $180,000. A detached ADU with a kitchen and bath sits between $180,000 and $320,000 depending on site access, septic and well setbacks, and whether you choose panelized construction or site-built. Second story additions range from $220,000 to $400,000 for full upper levels, with partial additions landing lower.
What moves the number most in Woodland Hills is your lot’s topography and its permit jurisdiction, not the size of the addition. A 750-sq-ft ADU on a flat Walnut Acres lot costs very differently from the same ADU on a hillside parcel requiring piers, retaining, and a pump-truck concrete pour. We put all of this in writing before work begins. Call (559) 282-2291 and schedule a free site walk and written estimate.
We Also Serve Cities Near Woodland Hills
Benson ADU Woodland Hills works across the southwestern Valley, including Canoga Park, Topanga, Tarzana, and West Hills. If you’re in one of those communities and researching a home addition or ADU, we’ll walk your property the same way we do here. We’re also actively building in Woodland Hills and the neighborhoods around it, and the same written-price guarantee applies wherever we work.
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 Home Addition Contractor in Woodland Hills
Septic and well setbacks directly limit where a detached ADU can sit on your lot, often pushing the structure toward the front or side of the property. If your Woodland Hills property uses a septic system or private well, the county requires minimum distances from the leach field and well head, and failing to account for these at the design stage gets plans rejected and costs you months. We identify septic and well locations during our first site walk and design the ADU footprint around those constraints before we quote anything. Call (559) 282-2291 to schedule that walk.
Yes. Hillside lots north of Ventura Boulevard typically require engineered drainage, slope stabilization, and sometimes retaining walls before foundation work can pass inspection. Flat-lot ADUs south of the Boulevard usually need only basic swales and downspout tie-ins. The engineering and grading difference on a hillside lot can add $30,000 to $80,000 depending on slope severity, soil type, and access for equipment. We include this in the written price, never as a surprise later.
Longer and narrower delivery routes mean staged deliveries, flagging crews, and sometimes pump trucks instead of direct chute pours, and those logistics add cost. On canyon properties off Mulholland or Topanga, concrete and framing deliveries cost more to coordinate, and that line item on our quote is explicit. We build the delivery plan into the scope before pricing. Call (559) 282-2291 and we’ll tell you exactly what the material logistics look like for your specific property.
Hillside areas in Woodland Hills fall under wildfire hazard zones that require ignition-resistant siding, enclosed eaves, and specific venting details. Our standard for hillside ADUs is James Hardie fiber-cement siding with the required vented assembly, which passes inspection the first time and protects your structure long-term. We build with these materials from day one, priced in the written quote.
Yes, a detached ADU can include a workshop, storage, or garage space, but the combined structure must still meet all residential ADU requirements: full kitchen, separate entrance, and minimum square footage for living space. The workshop portion gets priced at a different per-square-foot rate than the living space, which we break out in the written quote. We’ve built this exact combination for homeowners in Walnut Acres and along the canyon roads, and the county accepts it when the plans are drawn correctly from the start.
Call Benson ADU Woodland Hills for a Free Written Estimate

If you’re considering a home addition, second story, garage conversion, or detached ADU in Woodland Hills, the first step is a site walk. We’ll walk your lot, check jurisdiction, measure setbacks, look at access, and give you a written price with everything itemized. No verbal estimate that drifts later. Call (559) 282-2291 to schedule your free estimate.
Written by Troy Eastman, Owner at Benson ADU Woodland Hills, serving Woodland Hills, Canoga Park, Topanga, Tarzana, and West Hills.



