Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Sherman Oaks
Adding square footage or building an ADU in Sherman Oaks typically costs between $45,000 and $130,000 for a room addition, and $90,000 to $220,000 for a detached ADU. Those are honest Sherman Oaks numbers, not national averages. We’re Barrett & Sons Construction, and we’ve been building in this corridor long enough to know that a hillside lot south of Ventura Boulevard runs on different rules than a flat tract home in Valley Glen. If you’re thinking about a second story, a garage conversion, or a junior ADU off the back of your 1950s ranch, call (877) 610-1318. We’ll send someone who actually knows Sherman Oaks, and the estimate is free.
Why Barrett & Sons Construction Is Sherman Oaks’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run crews on Sherman Oaks job sites most days. That matters because a home addition is not a weekend project. It’s a five-figure commitment that goes through plan check, foundation work, framing, rough-in, and final inspection over months. Our Sherman Oaks customers tell us the same thing: they hired us because Tom puts his name, his address, and his license number on paper before anyone swings a hammer. You can look it up. If something’s not right at the end, our 90-Day Done Right Promise is written on the contract, not buried in the fine print. One call brings Tom back.
We answer our own phone. A live person picks up when you call (877) 610-1318, day or night. No out-of-state call center, no voicemail box that never calls back. For homeowners in Sherman Oaks who have already been burned by a national outfit that quoted one number on the phone and delivered another bill at the door, this is the difference that matters. We also run background-checked crew members who wear the Barrett & Sons name on their shirts, and every job includes permits pulled and inspections signed. The permit inspector works for you, not for me. That’s why I like him.
Our Home Additions & ADU Services in Sherman Oaks
ADU Design & Permitting
An ADU in Sherman Oaks is not a shed. It’s a dwelling unit, and the City of Los Angeles treats it as one. We handle the full design and permitting path: measured as-builts, LADBS plan check, soils and grading review where the hillside ordinance applies, and the actual permit pull. If your property is south of Ventura Boulevard toward Mulholland Drive, expect LADBS to ask for a soils report and possibly a retaining wall detail. We price that into the quote from day one. So many Sherman Oaks homeowners come to us after a flat-valley contractor gave them a number that fell apart at plan check. Our scope is in writing before anything moves.
Garage Conversion ADU
Converting an attached or detached garage into an ADU is the most common project we build in Sherman Oaks, and the range here runs $30,000 to $80,000. The wildcard in Sherman Oaks specifically is the 1960s and 1970s tuck-under apartment stock along the Ventura Boulevard corridor. If your building has parking at grade and living space above, the City’s soft-story retrofit ordinance may require seismic work before we can legally convert those bays. We detail that in the first quote, not after demolition starts. On a standard 1950s tract home garage, the job usually moves faster: new slab edge, insulation, electric subpanel, and a compact kitchenette and bath.
New Detached ADU
A new detached ADU in Sherman Oaks runs $90,000 to $220,000, and the spread depends heavily on your lot. A flat yard in the 91403 or 91423 zip with open access might sit at the lower end. A hillside lot near the Santa Monica Mountains foothills can push toward the upper end because of grading, drainage, and foundation engineering. We’ve built enough ADUs in this neighborhood to plan for both. The good news is that a detached ADU does not disturb your existing home during construction, which keeps the job cleaner and quieter for the main house.
Junior ADU & Interior Conversion
We build a lot of junior ADUs inside existing home footprints in Sherman Oaks. Think converting a three-car garage into a studio with a separate entrance, or carving a 400-square-foot unit out of an oversized den. These projects typically land between $45,000 and $90,000. Sherman Oaks has a huge stock of 1940s and 1950s ranch homes with generous floor plans and wasted space near the rear of the house. A junior ADU can convert that into income without touching the roofline or the setbacks. We pull the permits and run the utilities as a separate service so the unit can meter independently.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Sherman Oaks
We install real brands you can look up, because the last contractor most Sherman Oaks homeowners used told them the materials were “premium” and then showed up with a mystery brand off a van. In our ADU kitchens and baths we regularly install KraftMaid cabinetry, Sterling and Grohe fixtures, and Schluter waterproofing systems in showers. GAF shingles and underlayment go on any ADU roof we build. All of it is stocked locally, so if a replacement part is needed mid-job, we’re not waiting a week on a freight delivery. Our crews in Sherman Oaks carry what they need for the most common installations, and anything unusual gets sourced from suppliers we’ve worked with for two decades.
Common Home Additions & ADU Problems We See in Sherman Oaks Homes
- Hillside grading review on lots south of Ventura Boulevard: LADBS classifies much of the foothills south of Ventura Boulevard as landslide-prone hillside area. Even a modest 400-square-foot addition can trigger a soils report, retaining wall requirement, and drainage plan that a flat-valley contractor never mentions until the permit desk flags it. We price the soils work up front.
- Soft-story retrofit mandates on tuck-under buildings: The City of Los Angeles’s Ordinance 183893 targets the dense 1960s and 1970s apartment buildings along the Ventura Boulevard corridor. If you’re adding a second story or converting garage bays on one of these buildings, the retrofit work can add 20-30% to the scope and must be detailed before pull permits are issued.
- Expansive soils and summer heat: Sherman Oaks sits in the inland San Fernando Valley heat pocket. Concrete cures fast in 105-degree summer heat, which changes pour schedules and finishing windows. Unshaded lumber warps on delivery. We stage materials under cover and adjust pour timing accordingly. The expansive clay soils common on the valley floor also mean footing depth and rebar schedule need more attention than a coastal job.
- Staging deliveries on narrow canyon streets: The hillside streets south of Ventura Boulevard are tight. We plan lane closure and material staging before the first truck shows up. Sherman Oaks’s residential canyon pockets have strict noise and work-hour ordinances, and a stop-work order from a neighbor complaint will blow the draw schedule. We set expectations with neighbors in writing before we start.
Pricing for Home Additions & ADU in Sherman Oaks, CA
Here are the line-item ranges we quote in Sherman Oaks. These are not national numbers. They reflect local permit fees, LADBS hillside review, seismic requirements, and the cost of material staging on tight residential streets.
| Project Type | Typical Sherman Oaks Range |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
What moves your number within those ranges: foundation complications on expansive soils, soft-story seismic retrofit scope, hillside grading and retaining walls, and the condition of your existing electrical panel. We give you a written line-item quote before you sign anything, and every change order arrives in writing before work proceeds. No surprise invoices. Call (877) 610-1318 for a free estimate on your Sherman Oaks project.
Home Additions & ADU in Sherman Oaks: The Tight-Lot Reality
Building a room addition or ADU on a typical Sherman Oaks lot is different from building on a quarter-acre in Burbank or Glendale. Sherman Oaks sits entirely within the City of Los Angeles, where the mandatory soft-story retrofit zone and the landslide-prone hillside ordinance south of Ventura Boulevard create a dual compliance layer that flat-valley contractors often miss when bidding. That’s the biggest reason our written quotes in Sherman Oaks look different from a number someone pulled out of a Van Nuys price book.
Here’s an example from our own work. On a tight hillside street south of Ventura Boulevard toward Mulholland Drive, our crew converted a tuck-under parking bay into a junior ADU for a 1960s soft-story apartment building. LADBS soils and grading review triggered even for the modest 480-square-foot scope, and our load-bearing plan added steel moment frames before rough-in on the new Kohler bath and KraftMaid kitchenette. Split permits and a staged draw schedule kept the landlord’s tenants in place throughout, with inspection sign-off on the seismic retrofits before any drywall went up. That’s what an honest Sherman Oaks ADU quote includes.
Staging matters more than most homeowners expect. A narrow hillside street with no off-street parking means we need a lane closure plan before the lumber truck arrives. A 1940s tract duplex with a shared wall means a party-wall notice to your neighbor before we open up wall cavities for a second-story addition. We handle that paperwork. It’s part of the job. Your neighbor’s goodwill is a construction asset, and we protect it.
Rebuilding After the 1994 Northridge Earthquake: Why Sherman Oaks Construction Is Different
Sherman Oaks sits within the zone of maximum damage from the 1994 Northridge earthquake, and the City of Los Angeles’s mandatory soft-story retrofit ordinance directly targets the dense stock of 1960s-70s tuck-under apartment buildings lining the Ventura Boulevard corridor. That makes seismic retrofitting and post-retrofit renovation a defining driver of construction demand here in a way that simply does not apply to neighboring Burbank or Glendale. If you own a tuck-under apartment building, a 1960s duplex, or a hillside home near Mulholland Drive, the structural reality of this neighborhood shapes what we can build and how we have to build it. A contractor who does not know the difference between a Sherman Oaks hillside lot and a Valley Glen flat lot is not going to give you a reliable number.
We Also Serve Cities Near Sherman Oaks
Our crews work throughout the area around Sherman Oaks, including Valley Glen, Van Nuys, Studio City, and Encino. If you’re outside the 91403, 91413, 91423, or 91495 zip codes but close by, call (877) 610-1318 and we’ll confirm coverage. This page covers Home Additions & ADU in Sherman Oaks specifically, and we’re happy to price work in the surrounding neighborhoods. If you need more detail on what we build, start with our Home Additions & ADU service overview.
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 - Home Additions & ADU in Sherman Oaks
Yes, in nearly every case. LADBS classifies the Santa Monica Mountains foothills south of Ventura Boulevard as landslide-prone hillside area, which means a soils report and grading review are typically required before a detached ADU permit is issued. That report can add thousands to your budget, and we include it in our written quote from the start. Call (877) 610-1318 and we’ll tell you straight whether your lot triggers the hillside review.
Almost certainly yes if the building has parking at grade and living space above, and the retrofit will add 20-30% to your project scope. The City of Los Angeles’s soft-story retrofit ordinance mandates seismic bracing on the open-parking level before you can legally convert those bays to dwelling units. We detail shear walls and moment frames in the permit drawings, not after demolition starts. Get a written quote that includes the retrofit. Call (877) 610-1318.
We plan it before the first truck shows up. On tight hillside streets we schedule deliveries in small batches, use a lane closure plan where required, and stage materials on-site under cover to protect them from the 100-degree valley heat. On flat valley lots in the 91403 or 91423 zip, we usually have enough driveway space to work without blocking the street. Ask us for a site logistics note with your free estimate. It’s part of what we do.
Yes, in Los Angeles a party-wall notice is required before we modify a wall shared with your neighbor, and we handle that paperwork as part of the permit package. We also walk through the plan with your neighbor before work starts. It keeps the job moving and prevents the kind of dispute that turns into a stop-work order. We’ve done dozens of these in Sherman Oaks’s 1940s duplex stock near the Ventura Boulevard corridor.
Hillside overlay zones near Mulholland Drive require defensible-space vegetation clearance, specific egress window sizes, and often Class-A roofing on the ADU. We spec these into the plan set before plan check, so your drawings pass on the first review. In a high-fire-risk zone, the wrong egress detail or the wrong roofing assembly will bounce your permit. That’s delay you don’t need. Call (877) 610-1318 for a free estimate and we’ll walk the lot with you.
Call Barrett & Sons Construction for Your Sherman Oaks Home Addition or ADU
You’re not ready to buy. You’re ready to price. That’s why we give you a free, written, line-item estimate on your Sherman Oaks home addition or ADU before you commit to anything. Tom Barrett will put his name and license number on the quote. Every permit gets pulled. Every inspection gets signed. Every change order is in writing before work proceeds. And when the job is done, the 90-Day Done Right Promise is in writing too. Call (877) 610-1318. A live person answers.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Sherman Oaks since the company’s founding in 1998.