Fast, Reliable New Detached ADU Across Sherman Oaks
A new detached ADU in Sherman Oaks typically runs $220,000-$380,000 all-in, from permit set through final inspection, and every quote we release includes a whole-parcel seismic assessment before we name a number. We’re Ellery ADU Studio, and we’ve designed, permitted, and built ADUs across the San Fernando Valley since 2015 - including dozens of detached units on the flat Valley-floor lots that dominate Sherman Oaks. Our New Detached ADU in Sherman Oaks team coordinates dispatch from our Los Angeles office, with crews who know the difference between an LADBS structural review that passes clean and one that gets held up by unretrofitted garage framing.
Call (213) 329-7167 to schedule your free estimate. We’ll pull LADBS records on your parcel before we draft, so the price you receive accounts for what is actually there.
Why Ellery ADU Studio West Hollywood Is Sherman Oaks’s Preferred New Detached ADU Company
We’ve completed new detached ADUs on parcels from Milbank Street to the Van Nuys border, and our Sherman Oaks clients receive the same single-contract design-build model we apply everywhere: drawings, permit set, and construction under one written price, with no designer-versus-builder blame gap when something needs adjustment.
Our reviews from Sherman Oaks homeowners consistently note two things: the documented photo record we deliver after every site visit, and the fact that our written price - established under Haven Standard Clause 1 - did not change once work started. We’re not guessing at your foundation condition or your panel capacity. We verify before we quote.
Response time to Sherman Oaks is same-day for initial calls; a live person answers 24/7, and we typically schedule site assessments within 48 hours. Crews are background-checked, uniformed, and licensed, with license numbers on every page of our documentation.
Local expertise matters here because Sherman Oaks permitting runs through LADBS, and LADBS structural review for any new detached ADU triggers a whole-parcel seismic look. Most owners assume their property was retrofitted after 1994. The paperwork on file usually covers the main house only. We know to check this before we price.
Our New Detached ADU Services in Sherman Oaks

Custom Built ADU
Custom built ADUs in Sherman Oaks start around $280,000 and run to $380,000 or more depending on square footage, finish level, and site conditions. Every custom project begins with a whole-parcel seismic assessment - we pull LADBS records, walk the existing structures, and scope any cripple-wall or anchor-bolt work before the design moves past schematic. On a 1950s ranch parcel off Milbank Street in Sherman Oaks, we pulled LADBS records before drafting and found the main house had a post-1994 retrofit on file but the detached stucco garage had never been touched - unbolted mudsills and unbraced cripple walls that the structural reviewer flagged the moment our new detached ADU triggered a whole-parcel review. We scoped cripple-wall plywood sheathing and anchor bolts on the garage as a concurrent line item, upsized the 100-amp panel to carry a ducted mini-split sized for 108°F Valley afternoons, and added an ERV with MERV-13 filtration for wildfire-smoke season; we now build a whole-parcel seismic assessment into every Sherman Oaks quote before we release a number.

Prefab ADU Installation
Prefab ADU installation in Sherman Oaks typically ranges $220,000-$320,000, including transport, crane set, foundation, utility tie-ins, and LADBS permit coordination. We specify and coordinate prefab systems from Abodu, Cover, and Mighty Buildings - each with different transport dimensions that affect equipment access planning on 6,000-9,000 sq ft parcels. A flat Valley-floor lot does not mean automatic crane access; we survey gate widths, overhead lines, and staging area before quoting. The Haven Standard Clause 1 written price covers the full scope: prefab unit, foundation engineered for your soils report, panel upgrade if needed, and the ducted mini-split or ERV we specify for Valley heat and wildfire smoke. No post-delivery upsells.

Modular ADU
Modular ADUs in Sherman Oaks follow a similar price band to prefab - $230,000-$330,000 - with the added coordination of factory inspections and transport permits for oversized modules. We work with Dvele and Plant Prefab on modular systems, and our single-contract model means we handle factory liaison, LADBS plan check, and site assembly as one scope. Modular units often arrive with HVAC pre-installed; we verify that the factory spec handles 100-108°F Sherman Oaks afternoons, not coastal assumptions. If it doesn’t, we resize before the module ships.

Studio ADU and 1-Bed & 2-Bed ADU
Studio ADUs in Sherman Oaks run $220,000-$280,000; 1-bed units $260,000-$340,000; 2-bed units $300,000-$380,000. These ranges assume standard finish levels and include the seismic assessment, panel upgrade, and HVAC sizing as mandatory line items - not upgrades. A 2-bed detached ADU on a Sherman Oaks lot will trigger LADBS occupancy requirements that include egress windows, fire separation, and often a 200-amp service upgrade from the original 60-100 amp panel. We identify these requirements in the first site visit, not at permit submittal.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
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 specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie - not as a catalog to browse, but as systems we engineer into your single contract. For Sherman Oaks clients, this means we stock local knowledge of which factory lead times align with LADBS plan-check cycles, which transport dimensions clear Ventura Boulevard corridor routes, and which foundation systems suit the Valley’s alluvial soils. A Mighty Buildings unit with its polymer-composite panels performs differently in 108°F heat than an Abodu unit with its steel-frame envelope; we specify accordingly. The brand is a tool. The specification is our responsibility.
Common New Detached ADU Problems We See in Sherman Oaks Homes

- Unretrofitted detached garages triggering scope changes mid-permit. LADBS records show seismic work on the main house only. The detached garage - your ADU’s neighbor on the parcel - still has unbolted mudsills and unbraced cripple walls. We find this before we quote. Most competitors don’t look until the structural reviewer does.
- HVAC sized on coastal assumptions. Sherman Oaks runs 15-20°F hotter than Santa Monica. A mini-split spec’d for 85°F design temperature fails the first July heat event. We size every system for 108°F, with ERV and MERV-13 filtration for wildfire-smoke season.
- Undersized electrical panels. Original 1950s-1970s construction in Sherman Oaks typically includes 60-100 amp service. A new detached ADU with electric heat, cooking, and laundry often requires 200-amp upgrade. We scope this as a mandatory line item, not a surprise.
- Drainage and access assumptions on flat lots. A 6,000 sq ft parcel with a detached garage still needs pad elevation, drainage routing away from both structures, and equipment access planning before a prefab or modular set can be staged. Flat does not mean ready.
Pricing for New Detached ADU in Sherman Oaks, CA
| Service | Typical Range (Sherman Oaks) |
|---|---|
| Studio ADU (custom or prefab) | $220,000 - $280,000 |
| 1-Bed ADU (custom or prefab) | $260,000 - $340,000 |
| 2-Bed ADU (custom or prefab) | $300,000 - $380,000 |
| Whole-parcel seismic assessment | $1,200 - $2,500 (included in quote) |
| Cripple-wall retrofit / anchor bolts (if needed) | $4,000 - $10,000 |
| Electrical panel upgrade (100A to 200A) | $3,500 - $7,000 |
| Ducted mini-split or ERV with MERV-13 | $8,000 - $15,000 (mandatory, not upgrade) |
These ranges reflect Sherman Oaks’s LADBS permit fees, Valley labor rates, and the seismic and HVAC realities of this specific market. Every project receives a written price before any work starts - Haven Standard Clause 1 - and that price includes the whole-parcel seismic assessment, not a separate discovery phase. Call (213) 329-7167 for your exact quote; estimates are free, and we offer a Free Second Opinion on any written estimate already in hand.
We Also Serve Cities Near Sherman Oaks

Our New Detached ADU crews work across the Valley, including Van Nuys, Studio City, Tarzana, and North Hollywood. Each city carries its own LADBS or LA County permitting path, its own seismic history, and its own HVAC sizing assumptions. We adjust the scope accordingly before releasing a written price.
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 - New Detached ADU in Sherman Oaks

Sherman Oaks is within the City of Los Angeles boundaries, so new detached ADUs are permitted through LADBS (Los Angeles Department of Building and Safety), not LA County. This matters because LADBS enforces the whole-parcel seismic review that catches unretrofitted detached garages. Call (213) 329-7167 and we’ll pull your parcel’s LADBS record before quoting.
No. In nearly every Sherman Oaks case we’ve reviewed, the post-1994 retrofit paperwork covers the main dwelling only. The detached garage almost always retains unbolted mudsills and unbraced cripple walls. When your new detached ADU triggers whole-parcel structural review, LADBS will flag this. We scope the garage retrofit as a concurrent line item before we release your written price. Call (213) 329-7167 for a free estimate that includes the seismic assessment.
We specify ducted mini-splits or ERV systems with MERV-13 filtration, sized for 108°F design temperature - not coastal assumptions. This is a mandatory line item on every Sherman Oaks quote, not an upgrade. The Valley’s poor air dispersion during wildfire season makes the filtration component equally non-negotiable. Call (213) 329-7167 and we’ll size the system for your specific square footage and orientation.
Sherman Oaks properties are served by city sewer and water, so septic and well setbacks do not apply. However, LADBS does enforce setback requirements between your new detached ADU and the property line, typically 4 feet side and rear for structures under 18 feet height. We verify these dimensions during the site assessment and note them on the permit set before submittal. Call (213) 329-7167 to schedule the assessment.
Prefab and modular units require crane or forklift access, overhead-line clearance, and staging area on your parcel or the street. On 6,000-9,000 sq ft Sherman Oaks lots with detached garages, we often need to remove the existing garage slab or grade for drainage before the set. These are scoped as line items in your written quote - not surprises at delivery. Call (213) 329-7167 for an estimate that includes access planning.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Sherman Oaks since 2015.