Fast, Reliable Garage Conversion ADU Across Westlake Village
A garage conversion ADU in Westlake Village typically runs $85,000-$165,000 all-in, from measured drawings through final inspection, depending on whether the structure is attached, detached, and what the jurisdiction and HOA require for finishes. We’re Ellery ADU Studio, and our Garage Conversion ADU team serves Westlake Village from our Los Angeles office, with crews who know the difference between a City of Westlake Village parcel, a Ventura County unincorporated lot, and a Thousand Oaks address that still reads “Westlake Village” on the mailbox. Call (805) 301-9518 to schedule your free estimate. We’ll verify your jurisdiction before we quote.
Why Ellery ADU Studio Camarillo Is Westlake Village’s Preferred Garage Conversion ADU Company
We’ve designed, permitted, and built ADUs across the master-planned neighborhoods of Westlake Village since 2015, the year California’s ADU laws began their major shift. Our 900+ projects include conversions on Foxmoor Court, Triunfo Canyon, and throughout the South Shore neighborhood, where we’ve learned which HOA architectural committees require James Hardie siding match and which accept updated materials that still comply with the original CC&Rs.
Westlake Village homeowners find us through referral and repeat search, and they stay because we deliver what we document. Every client receives a written price before any work starts, per Haven Standard Clause 1, a documented photo record on every site visit, and the 365-Day Done Right Promise in writing. No voicemail queues, either. A live person answers calls 24/7.
Our response time to Westlake Village is same-day for initial site visits, because dispatch and scheduling are coordinated from our Los Angeles office with crews already working the Conejo Valley. We don’t subcontract design to a separate firm or construction to a separate contractor. One contract, one written price, one point of accountability.
Our Garage Conversion ADU Services in Westlake Village

Attached Garage Conversion
Attached garage conversions in Westlake Village are the most common project we see, especially in the 1960s-1990s tract homes off Triunfo Canyon and Lindero Canyon. The existing structure shares a wall with the main house, which simplifies utility tie-ins but complicates firewall and sound separation requirements. We measure the existing slab for bearing capacity, document the builder-grade drywall and hollow-core doors typical of this era, and spec the upgrade path that satisfies both the permit agency and your HOA. A typical attached garage conversion in Westlake Village runs $85,000-$125,000, drawings through final inspection.

Detached Garage Conversion
Detached garages in Westlake Village face a constraint most cities don’t: large portions of the city sit in CAL FIRE’s Very High Fire Hazard Severity Zone, so any detached structure must meet ignition-resistant construction standards. That means ember-resistant vents, Class A roofing, and fire-rated siding. These aren’t upsells. They’re code. We spec these from the first permit set so you’re not redesigning at plan check. A detached garage conversion in Westlake Village typically runs $110,000-$165,000, with VHFHSZ material costs built into the written price.

Carport Conversion
Carport conversions in Westlake Village are less common but increasingly requested, especially where homeowners want to preserve the master-plan streetscape while adding rental income. The challenge is structural: most carport slabs aren’t designed for enclosed, conditioned space, and the open sides need full enclosure with proper footings. We handle the engineering and the jurisdiction verification together, because a carport on the Ventura County side of the line faces different setback rules than one on the City side.

Garage Partition & Bathroom Add
This is where we split an existing garage into a JADU plus retained storage, or add a bathroom to a previously unconditioned space. In Westlake Village’s 3-car garage stock, this is often the right financial move: keep two bays for vehicles or storage, convert one into a studio or one-bed unit. The bathroom add drives the permit complexity, sewer connection, and ventilation. We document the existing conditions, spec the partition for sound and fire rating, and deliver a scope that doesn’t void your builder warranty by cutting into structural elements without a documented path.

Garage JADU
A Garage JADU, or Junior ADU, is the smallest permitted unit type and the fastest to permit in most Westlake Village jurisdictions. It’s owner-occupied, shares bathroom or kitchen facilities with the main house, and caps at 500 square feet. For homeowners who want rental flexibility without the full ADU cost, this is the entry point. We see strong demand in the South Shore and Foxmoor areas, where the original 3-car garages offer enough footprint to sacrifice one bay and still park two cars. Typical range: $65,000-$95,000.

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.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Coordinate in Westlake Village
Ellery ADU Studio specifies and coordinates prefab and modular systems from Abodu, Cover, and Mighty Buildings, among others, within the same single-contract framework we use for stick-built conversions. For Westlake Village’s HOA-governed master plans, we often pair these systems with James Hardie siding on street-facing elevations to satisfy architectural review while meeting VHFHSZ ignition-resistant requirements. The brand choice affects timeline more than quality; we select based on your jurisdiction’s permit familiarity, your HOA’s material standards, and the specific fire zone designation of your parcel.
Common Garage Conversion ADU Problems We See in Westlake Village Homes

- Wrong agency, wrong permit, restarted timeline. A contractor who doesn’t pull the county parcel map first can file with Ventura County Planning Division when the lot is actually City of Westlake Village, or vice versa. Each agency charges different fees and enforces different rear setbacks. We verify jurisdiction before we draw.
- Cosmetic upgrades masking real scope drivers. Homeowners in newer Westlake Village tracts often want to replace builder-grade cabinets, hollow-core doors, and fluorescent fixtures first. The real cost drivers are VHFHSZ construction standards and HOA design compliance. We help you spend where it matters.
- Builder warranty voided by undocumented structural cuts. Cutting into the main electrical panel, HVAC trunk, or load-bearing wall for your garage conversion without a warranty-compliant path can invalidate your home’s original builder coverage. We document the structural path before any cuts.
- HOA design standards applied too late. California AB 670 prohibits HOAs from blocking ADUs outright, but Westlake Village’s master-plan CC&Rs can impose material, color, and elevation standards that add cost if not addressed in the initial permit set. We review CC&Rs during design, not after construction starts.
Pricing for Garage Conversion ADU in Westlake Village, CA
| Service Type | Typical Range (Westlake Village) |
|---|---|
| Garage JADU (500 sq ft max) | $65,000 - $95,000 |
| Garage Partition & Bathroom Add | $75,000 - $115,000 |
| Attached Garage Conversion | $85,000 - $125,000 |
| Detached Garage Conversion | $110,000 - $165,000 |
| Carport Conversion | $95,000 - $140,000 |
These ranges include design, permit set, jurisdiction fees, construction, and final inspection. What moves you within the range: VHFHSZ material requirements, HOA-mandated finish upgrades, slab condition, electrical service size, and sewer connection distance. Under Haven Standard Clause 1, every project is quoted with a written price before any work begins. No “call for pricing.” The number you receive is the number on the contract. Call (805) 301-9518 for your free estimate.
We Also Serve Cities Near Westlake Village

Our crews work the full Conejo Valley and western San Fernando Valley corridor, including Garage Conversion ADU in Westlake Village proper plus Thousand Oaks, Agoura Hills, Oak Park, and Calabasas. Jurisdiction verification matters in all of these cities, but nowhere more than Westlake Village, where the county line cuts through residential neighborhoods.
Serving Westlake Village, CA - Our Local Coverage Area
We’re based in the Westlake Village 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 - Garage Conversion ADU in Westlake Village

Only if your parcel sits within CAL FIRE’s Very High Fire Hazard Severity Zone, which covers large portions of Westlake Village north and west of Lindero Canyon Road. If you’re in the zone, detached ADUs and any new exterior envelope work must use ember-resistant vents, Class A roofing, and fire-rated siding. We verify your parcel’s fire zone designation during our first site visit and build those material costs into the written price. Call (805) 301-9518 to check your address.
No. Under California AB 670, HOAs cannot prohibit ADUs outright, including in Westlake Village’s master-planned communities. Your HOA can enforce design and material standards from the original CC&Rs, which in Westlake Village often specify James Hardie siding, certain roof profiles, or color palettes. We review your CC&Rs during the design phase and spec compliant materials so the project passes architectural review without delay. Call (805) 301-9518 and we’ll pull your HOA documents.
It depends on your parcel’s jurisdiction, not your mailing address. A Triunfo Canyon-area home can fall under City of Westlake Village (LA County), unincorporated Ventura County, or Thousand Oaks, each with different ADU size caps, rear setbacks, fees, and review timelines. We run the county parcel map before any design or pricing. Getting this wrong means a rejected application, lost fees, and weeks of delay. Call (805) 301-9518 and we’ll verify your jurisdiction in our first call.
It can, if structural framing, the main electrical panel, or HVAC systems are modified without a documented, warranty-compliant path. Our process includes a pre-construction warranty review and a structural path documented in the permit set, so your builder warranty remains intact where possible. We don’t cut first and ask questions later. Call (805) 301-9518 to review your specific warranty terms.
Prioritize the entry door, lighting, and any exposed drywall. Hollow-core doors and fluorescent fixtures are typical in Westlake Village’s 1980s-1990s stock and they’re the fastest payback for tenant comfort and code compliance. Cabinets and flooring can often wait if the budget tightens; the door, lighting, and proper ventilation cannot. We document what’s existing, spec what’s required, and flag what’s optional so you decide with full information. Call (805) 301-9518 for a free estimate.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Westlake Village since 2015.