Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Sherman Oaks
A typical home addition or ADU in Sherman Oaks runs $45,000-$130,000 for attached builds and $90,000-$220,000 for detached units, with most projects taking 4-8 months from permit to final inspection. We quote every job with a flat written price before any work starts. Call (213) 652-7670 to schedule your free estimate.
We’ve worked Sherman Oaks lots for years - from the post-war ranches north of Ventura Boulevard to the dingbat apartment blocks along Kester Avenue and Hazeltine Avenue. These are tight sites with shared walls, limited staging space, and parking that disappears by 8 a.m. Our crews know how to stage a concrete pour on a 40-foot lot, coordinate party-wall notice with tenants on night shifts, and get materials through when the driveway is the only access point. Dispatch and scheduling run from our Los Angeles office, but the crews serving Sherman Oaks live in the Valley and understand the local LADBS plan-check path.
Why Rowan Construction Group Los Angeles Is Sherman Oaks’s Preferred Home Additions & ADU Company
We’ve delivered 4,000-plus projects since 2007, every one with a written price before work started and a documented photo record when the crew left. In Sherman Oaks specifically, that discipline matters because the projects here carry extra layers: soft-story retrofit triggers, hillside fire-hazard material requirements, and the heat management that Valley construction demands.
Our customers in Sherman Oaks find us the way most do now - they read the three-star reviews, look for the price range on the page, and want a text confirmation of the appointment window. We deliver that. Calls are answered by a live person 24/7, not a queue. Our technicians are background-checked, uniformed, and arrive with a photo-documentation routine that produces a record of what was found and what was done, included as standard.
The 365-Day Done Right Promise backs every project: if it is not done right, we make it right. That guarantee is printed on every page and backed by a terms page, not an asterisk. Under Clause 1 of The Haven Standard, the price is written before anyone starts - no exceptions, no “call for a quote.”
We also offer a Free Second Opinion on any written estimate. Bring a competitor’s quote and we’ll review it line by line at no charge.
Our Home Additions & ADU Services in Sherman Oaks

ADU Design & Permitting
ADU permitting in Sherman Oaks runs through LADBS, but the path is rarely straight. On blocks like Kester and Hazeltine, the 1960s-1970s dingbat soft-story apartments fall under LA’s mandatory retrofit Ordinance 183893 - so even a detached ADU behind a fourplex often triggers a structural review of the existing open-tuck-under parking beneath it. We engineer that review into the initial scope, not as a mid-permit change order. Our design team coordinates the ADU plans and the soft-story retrofit drawings as a single LADBS submission, which shaves weeks off plan-check compared to sequential filings. A typical detached ADU in Sherman Oaks runs $90,000-$220,000 depending on size, utility tie-ins, and whether the existing structure needs seismic work.

Garage Conversion ADU
Garage conversions in Sherman Oaks run $30,000-$80,000 and represent the fastest path to rental income on lots where a detached unit won’t fit setback rules. The catch: many Sherman Oaks garages sit behind or beneath soft-story apartments, and LADBS plan-check will flag the parent structure’s seismic status before signing off on the conversion. We pull the existing permit history in pre-construction so that surprise doesn’t surface mid-project. For hillside garages toward Mulholland Drive, we also verify fire-hazard severity zone status, which triggers Chapter 7A ember-resistant exterior material requirements that add cost and lead time.

New Detached ADU
New detached ADUs are our most requested Sherman Oaks project, and the most complex. On a typical 5,000-square-foot Valley floor lot, we’re fitting a 600-1,000 square foot structure with setback clearances, utility trenching, and often a shared driveway with the main house. We pour concrete at 6 a.m. to beat the Valley heat that blistered a slab we once saw a competitor pour at noon in July. Staging is tight - materials arrive just-in-time because there’s no side yard to store lumber. We coordinate party-wall notice with neighbors upfront, since a complaint during inspection can stop the job. The result is a permitted, rentable unit that clears LADBS and the fire department on first pass.

Junior ADU & Interior Conversion
Junior ADUs - conversions within the existing footprint, with a separate entrance - run toward the lower end of our range and avoid many of the setback and utility complications of detached builds. In Sherman Oaks’s 1950s-1960s ranch homes, we’re often converting a rear bedroom or attached garage bay, which means working with the original post-WWII framing, electrical panels, and sometimes unpermitted additions that previous owners layered on. We document what we find, photograph the existing conditions, and build any required upgrades into the written scope before work starts.

Second Story Additions
Second-story additions in Sherman Oaks face a unique constraint: the existing structure’s soft-story status. Adding weight above a 1960s dingbat with open-tuck-under parking almost always triggers Ordinance 183893 retrofit requirements, because the new load path has to connect to a seismically competent foundation. We engineer this as a single project, not two. The alternative - bidding the addition alone and discovering the retrofit mid-permit - produces change orders that can run $15,000-$40,000. Our written quote includes the structural review upfront.

Room Additions & Sunrooms
Room additions and enclosed patios follow similar staging and access constraints. On tight Sherman Oaks lots, we often build the foundation and frame with hand-carried materials because a boom truck won’t fit the driveway angle. We factor that labor into the written quote - no surprise equipment charges later.

What happens when you call
- 1
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.
Before
AfterTrusted Brands We Service in Sherman Oaks
We source across fifty-plus vetted brands, which lets us write honest numbers rather than inflated ones. For ADU and addition foundations in Sherman Oaks’s expansive-soil zones, we specify Sakrete high-strength mixes with documented compressive ratings. For prefabricated detached units where speed matters on a tight lot, we’ve worked with Abodu and Cover on factory-built modules that arrive 90% complete, reducing on-site construction time and neighbor disruption. For custom hillside builds toward Mulholland, Dvele’s precision-engineered systems integrate well with the slope-grading and retaining-wall requirements these sites demand. We stock local access to all three lines, which keeps material lead times inside the project schedule rather than driving it.
Common Home Additions & ADU Problems We See in Sherman Oaks Homes

- Soft-story retrofit surprises mid-permit. LADBS plan-check catches the open-tuck-under parking after the ADU or second-story addition is already designed, forcing a stop-work while steel moment frames are engineered and installed. We catch this in pre-construction by pulling the existing building’s permit history and running a preliminary structural review.
- Heat-damaged concrete and roofing materials. Sherman Oaks’s 100°F+ Valley heat - rarely seen on the coast - blisters fresh concrete poured past mid-morning and degrades roofing adhesives applied in afternoon sun. We schedule pours for dawn and plan roofing around morning-only application windows.
- Fire-hazard material compliance on hillside lots. Properties near the Santa Monica Mountains foothills fall into high fire-hazard severity zones, requiring Chapter 7A ember-resistant siding, decking, and vent screens. Contractors unfamiliar with this requirement arrive at inspection with standard materials and fail. We verify zone status before specifying.
- Neighbor complaints stopping inspection sign-off. On dense Kester and Hazeltine blocks, a tenant on night shift who wasn’t given proper party-wall notice can file a complaint that halts the final. We handle notice delivery, work-hour coordination, and direct neighbor communication as a standard project step.
Pricing for Home Additions & ADU in Sherman Oaks, CA
These are the ranges we see on actual Sherman Oaks jobs, written into our quotes before work starts:
| Project Type | Price Range in Sherman Oaks |
|---|---|
| ADU Construction (detached) | $90,000-$220,000 |
| Home Addition (attached room/second story) | $45,000-$130,000 |
| Garage Conversion ADU | $30,000-$80,000 |
What moves the number: soft-story retrofit requirements, hillside fire-zone materials, utility trenching length, and whether the lot allows standard equipment access or requires hand-carry labor. Every quote is a flat price with a written scope and a written warranty. No change proceeds without a signed change order - the discipline that has kept our projects within a few percent of the agreed cost across 4,000-plus jobs. Call (213) 652-7670 for your free estimate.
We Also Serve Cities Near Sherman Oaks

Our crews work the full San Fernando Valley corridor. We regularly pull permits and stage jobs in Sherman Oaks plus Van Nuys, Encino, Studio City, and Tarzana. Each city has its own LADBS plan-check quirks and local conditions - Van Nuys’s industrial zoning mix, Encino’s larger hillside lots, Studio City’s tighter noise ordinances - and we calibrate our scope and staging to match. If you’re comparing contractors across Valley cities, bring us any written estimate for a free line-by-line review.
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

It often does, if the existing structure is a 1960s-1970s dingbat with open-tuck-under parking. LADBS plan-check will flag the soft story when the ADU load path connects to or loads the existing foundation. We engineer this review into our initial scope and submit the ADU plans and retrofit drawings together, avoiding the mid-permit stop-work that catches contractors who didn’t check. Call (213) 652-7670 and we’ll review your property’s permit history at no charge.
Tight lots add 10-20% to labor costs on average, because materials often arrive just-in-time, equipment access is limited, and hand-carry staging replaces crane or boom-truck delivery. On Kester and Hazeltine blocks, we’ve built with lumber packages broken down to 16-foot lengths because 20-footers wouldn’t turn the driveway corner. We factor this into the written quote upfront - no surprise equipment charges later. Call (213) 652-7670 for a site-specific estimate.
Under Clause 1 of The Haven Standard, you should have a flat written price, a written scope of work, a written warranty, and a documented photo record of existing conditions. No work starts until all four are in hand. Any contractor who asks you to “call for a quote” or starts work on a handshake is not following a documented process. Our quote includes the LADBS permit path, the inspection schedule, and the change-order protocol.
Yes, if the property falls within a high fire-hazard severity zone, which covers much of the southern hillside fringe toward Mulholland Drive. Chapter 7A of the California Building Code requires ember-resistant siding, decking, and vent screens with specific ASTM ratings. These materials cost more and carry longer lead times than standard equivalents. We verify zone status in pre-construction and build the upgrade into the written scope, not as a mid-project surprise. Call (213) 652-7670 to check your parcel’s status.
LA’s noise ordinance limits construction to 7 a.m.-7 p.m. weekdays and 8 a.m.-5 p.m. Saturdays, with no Sunday work. On tenant-occupied dingbat blocks, we deliver party-wall notice 30 days in advance, coordinate our noisiest work (demolition, concrete cutting) with tenant schedules, and keep a direct phone line open for the neighbor to call our site lead. We’ve learned that a tenant who knows your name rarely files the complaint that stops inspection. The 6 a.m. concrete pours are scheduled with the city, not assumed.
Our Home Additions & ADU team is ready to review your Sherman Oaks project. Call (213) 652-7670 to schedule your free estimate. We’ll pull your property’s permit history, check for soft-story and fire-zone triggers, and deliver a flat written price with a written scope before any work starts.
Written by Grant Rowan, Owner at Rowan Construction Group, serving Sherman Oaks since 2007.







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