







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 Sherman Oaks
Adding an ADU on a Sherman Oaks lot means dealing with two very different sets of rules. Flat parcels east of the 405 usually sail through plan check with standard slab-and-stem-wall details. Hillside parcels west of the freeway, especially the ridges above Woodman Ave and Van Nuys Blvd, hit Los Angeles’ BASELINE Hillside ordinance, slope-density review, and drainage requirements that flat-lot builders rarely mention until change orders show up. That’s the honest terrain here. Our ADU Builders team has walked enough Sherman Oaks hillside jobs to know the difference before we quote, not after. Call (903) 568-7222 for a free estimate, and we’ll scope your lot against actual Sherman Oaks conditions, not a generic per-square-foot number.
Why Benson ADU Builders Is Sherman Oaks’s Preferred ADU Builders Company

Sherman Oaks homeowners keep our calendar full because we show up with a written price before any work starts. That’s not a slogan. Troy Eastman, who leads Benson ADU Builders, built the company around one rule: nobody on our crew digs a hole until the homeowner has line items on paper. Sherman Oaks clients hear that and relax, because half of them have already been burned by a verbal estimate that grew 30% at the framing stage.
Our Sherman Oaks reviews tell the same story. Customers mention the uniformed, background-checked crews who name every trade term in plain English, the written guarantee on each project, and the 365-Day Done Right Promise that puts real teeth in the phrase “we’ll make it right.” Part of the Relay Home Co. family since 2006, Benson ADU Builders coordinates scheduling through our Los Angeles office, but the crews serving Sherman Oaks are local to this side of the hill.
We also answer the phone. A live person, 24/7, no voicemail maze. If you’re pricing a two-bedroom detached ADU on a sloped lot off Valley Vista Blvd and want to know whether drilled piers are in the budget, you’ll get a human who understands the question.
Detached ADU in Sherman Oaks
Detached ADU work in Sherman Oaks typically runs $180,000 – $420,000 depending on whether your lot is flat or hillside, stick-built or panelized, studio or two-bedroom. That range isn’t a hedge. Flat lots east of the 405, where a standard slab foundation clears plan check, sit at the lower end. Hillside lots west of the freeway, where drilled piers, retaining, and a stamped drainage plan become part of the foundation package, push toward the upper end. We quote both scenarios from the first site visit.
Hillside Foundation Design
Sherman Oaks’ hillside parcels west of the 405 trigger slope-density and drainage review under the BASELINE Hillside ordinance. That means footing and foundation design follows per-lot geology from a geotech report, not a one-size-fits-all slab detail. We pull the geotech early, before plan check, because a footing detail that stalls review costs more in schedule than it saves in engineering fees.
Flat-Lot Detached ADUs
On flat Sherman Oaks parcels, a detached ADU can go from permit to final in 7 – 10 months with a standard slab-on-grade foundation and wood-frame or panelized walls. These jobs are faster. The cost drivers shift to utility trenching, separate meter work, and whether you choose site-built framing or a prefab system like Abodu or Cover. We price each path out loud.
JADU in Sherman Oaks

JADU work in Sherman Oaks (a Junior ADU, which converts existing space inside or attached to the primary home) typically runs $80,000 – $160,000. Los Angeles allows a JADU up to 500 square feet with its own efficiency kitchen, and Sherman Oaks homeowners often use one to create a rental without the setback and parking requirements a detached ADU carries. The catch on hillside lots is less about slope and more about the existing floor plan: Sherman Oaks’ older ranch and mid-century homes sometimes need structural upgrades to make the conversion legal.
Garage Conversions as JADU
A detached garage on a flat Sherman Oaks lot converts to a JADU faster than most homeowners expect. You already have the shell, the roof, and usually the setback. We focus the budget on foundation retrofits, insulation, a compliant kitchen, and a separate entrance. On hillside parcels, the garage slab itself sometimes needs geotech review if the slope has shifted over decades.
Interior Space JADUs
Converting a large bedroom or den into a JADU keeps everything inside the existing footprint. Sherman Oaks ranches from the 1940s and 50s often have oversized rooms near a rear door, which makes a conversion far cheaper than a ground-up detached build. The tradeoff is sharing utility connections with the main house, which some owners prefer and others avoid if they want a fully separate rental meter.
Trusted Brands We Service in Sherman Oaks
Benson ADU Builders is authorized to build with Abodu, Cover, Dvele, and Plant Prefab, plus James Hardie cladding, so Sherman Oaks homeowners choose from real product lines instead of whatever lumber the local yard has in stock. If you want a panelized Abodu unit on a hillside foundation, we handle the full kit ordering, delivery coordination, and local site work. If you prefer a James Hardie-clad site-built ADU, we spec that too. The brand choice is yours, but the site work, foundation, utilities, and permitting are ours, and that’s where Sherman Oaks hillside lots separate good builders from guessing builders.
Common ADU Builders Problems We See in Sherman Oaks Homes
- Flat-lot pricing on a hillside parcel. Builders quote a slab foundation, then plan check flags the slope, and suddenly the homeowner owes drilled piers, retaining, and a drainage plan. We see this constantly on the blocks off Woodman Ave and Van Nuys Blvd above the boulevards.
- Skipping geotech to save a few weeks. The Sherman Oaks plan check process will catch a missing slope-density submittal. The correction doesn’t just add cost; it resets your review timeline by a month or more.
- Prefab kits sold as “turnkey.” An Abodu, Cover, or Boxabl unit covers the structure. It does not cover the hillside foundation, utility trenching, site grading, or drainage. We quote the full job, not just the kit.
- Older ranch homes with undocumented additions. Sherman Oaks has thousands of 1940s and 50s ranch houses, and plenty of them have unpermitted sunrooms or garage conversions. Those have to be addressed before the city signs off on a new ADU.
Pricing for ADU Builders in Sherman Oaks, CA
Here’s the honest market picture for Sherman Oaks in 2025. A flat-lot detached ADU runs $180,000 – $320,000. A hillside detached ADU west of the 405 runs $250,000 – $420,000 due to foundation, retaining, and drainage work. A JADU conversion runs $80,000 – $160,000. A prefab unit from Abodu or Cover starts around $190,000 for the structure, and the foundation, utilities, and site work add $60,000 – $120,000 depending on slope. Every Benson quote is a written line-item price before work starts, so if the hillside eats more foundation budget than you hoped, you’ll see the number on paper, not in a surprise invoice. Call (903) 568-7222 for a free estimate.
We Also Serve Cities Near Sherman Oaks
Our crews regularly build across Van Nuys, Encino, Studio City, and Tarzana, so if you’re close to the Sherman Oaks border on either side of the 405, we’ve likely already handled a lot with your exact slope conditions. ADU Builders in Sherman Oaks know the difference between a Woodman Ave hillside and a flat Encino parcel because we work both every month.
Serving Sherman Oaks, CA - Our Local Coverage Area
We’re based in the Sherman Oaks 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 Sherman Oaks
Yes, if your lot is on a Sherman Oaks hillside. Plan check on slope-density and drainage review adds four to eight weeks compared to a flat Encino or Van Nuys parcel. Flat Sherman Oaks lots are as fast as anywhere in the Valley, roughly 7 – 10 months from permit to final. Call (903) 568-7222 and we’ll tell you which timeline your specific lot falls on.
Foundation conditions discovered after demo, undocumented existing additions that must be corrected, and utility service upgrades (especially on homes where the electrical panel predates 1980) are the three big ones. On Sherman Oaks hillside lots, the geotech report can also uncover soil conditions that require deeper piers than the plan assumed. Benson quotes these as known costs upfront, and when a change is unavoidable, it’s a written line item you approve before we proceed, not a surprise at the door.
On a standard 6,500 – 7,500 square foot flat Sherman Oaks lot, yes, in many cases. Los Angeles allows one ADU and one JADU on the same parcel, and the JADU often goes into the garage or a rear bedroom while the detached ADU fills the backyard. Hillside lots are trickier because the slope eats buildable area. Call (903) 568-7222 and we’ll check your lot dimensions and slope before you spend on plans.
No. The prefab unit covers the factory-built structure delivered to your site. It does not cover foundation, site grading, utility trenching, permitting, or connection work. On Sherman Oaks hillside parcels, the foundation alone can match the kit cost. Benson prices the entire site package, not just the structure, so you know the real total before you sign.
You’ll need building, electrical, plumbing, and mechanical permits from the Los Angeles Department of Building and Safety, plus a hillside foundation review if your lot triggers the BASELINE ordinance. Inspections happen at footing, framing, rough electrical/plumbing, insulation, and final stages. Benson pulls the permits and coordinates every inspection as part of the job. Call (903) 568-7222 and we’ll walk you through the exact sequence for your parcel.
Call Benson ADU Builders for Your Sherman Oaks Project

If you’re on a flat lot near Riverside Drive or a hillside block off Woodman Ave, the next step is the same: get a written price before you commit. Benson ADU Builders sends a crew to your Sherman Oaks lot, reviews the slope, checks access for equipment, and returns a line-item estimate you can hold in your hand. No pressure, no vague numbers, no change orders hiding behind the word “unforeseen.” Call (903) 568-7222 today to schedule your free estimate. Troy Eastman and the Benson team are ready to answer.
Written by Troy Eastman, Owner at Benson ADU Builders, serving Sherman Oaks since the company’s founding in 2006.



