Garage Conversion ADU in West Hills - Plans, Permits & Build, One Fixed Price

Fast, Reliable Garage Conversion ADU Across West Hills

A garage conversion ADU in West Hills typically runs $165,000-$245,000 all-in, drawings through final inspection, with fire-hardening requirements adding $8,000-$18,000 compared to a similar project in flat Canoga Park. Most West Hills garage conversions take 5-8 months from first survey to certificate of occupancy, and the single biggest variable is whether your lot falls inside the Very High Fire Hazard Severity Zone that covers much of the neighborhood’s southern and western edges. Our team knows which West Hills blocks trigger which requirements before we ever draw a line, because we’ve permitted and built these projects here, not just read about them. Call (971) 497-2402 and we’ll walk your specific street and parcel through the numbers.

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Why Ellery ADU Studio Is West Hills’s Preferred Garage Conversion ADU Company

Ellery ADU Studio has designed, permitted, and built over 900 ADUs since 2015, and West Hills projects hold a distinct place in that body of work. The homes here are overwhelmingly post-war ranches from the mid-1950s through the late 1970s, sitting on lots of 8,000 to 14,000 square feet or more. That parcel size makes garage conversions physically straightforward. What catches out-of-area contractors is the LADBS fire-zone overlay on the hillside blocks. We’ve shepherded conversions through those inspections repeatedly, including the specific moment an inspector checks for 1/16-inch ember-resistant mesh on eave and foundation vents before signing off. Nadia Ellery founded the studio on a simple idea: the permit set is the product. Everything else follows from drawings that anticipate the inspector’s checklist, not drawings that get revised mid-framing.

Our West Hills clients work with one contract, one written price, and one point of accountability. Photographic documentation comes on every visit under The Haven Standard, and a live person answers calls 24/7. When a West Hills homeowner brings us a written estimate from another company, we’ll review it at no charge and tell you honestly whether the fire-zone items, panel service, and geotechnical review are priced in or about to become change orders.

Our Garage Conversion ADU Services in West Hills

Every Garage Conversion ADU we build in West Hills starts with the same step: a site-specific review of your parcel against the VHFHSZ map, your existing panel capacity, and any hillside or canyon-adjacent lot conditions. That review happens before we quote, which means the written price you receive includes the items other firms leave out and spring on you later. Here’s how the three most common West Hills conversion types break down.

Attached Garage Conversion

Most West Hills garages are attached to the main house, typically a two-car structure on a ranch built between 1955 and 1975. Converting an attached garage means the new ADU shares one or more walls with your existing home, which simplifies utility runs and often reduces the per-square-foot cost compared to a detached build. On a recent 12,000-square-foot lot near the southern edge of West Hills, our crew converted an attached two-car garage from a 1963 ranch into a one-bedroom ADU. The original 100-amp panel couldn’t handle the new mini-split and induction cooktop, so we first installed a 200-amp service upgrade, then framed the garage-to-house opening with a shear-rated header and rerouted the soil vent through a new side wall to meet LADBS plumbing clearance. Attached conversions in West Hills typically run $155,000-$225,000 depending on finish level and fire-zone scope.

Garage Partition & Bathroom Add

If you want to convert only part of your garage and keep the rest as a workshop or storage, a partition conversion is the cleanest path. We frame a code-compliant separation wall with the required fire rating, add a bathroom and kitchenette on the ADU side, and leave your workbench untouched on the other. West Hills homeowners on larger lots like this option because they keep the garage function while generating rental income. The catch: the ADU still needs its own dedicated panel circuit, its own water heater or tankless unit, and its own HVAC, and all fire-zone venting requirements apply to the converted portion. Partition conversions with a full bath typically run $135,000-$195,000 in West Hills.

Detached Garage Conversion

Detached garages are less common in West Hills than attached ones, but they do appear on larger parcels, especially in the neighborhoods that slope toward the Santa Monica Mountains foothills. A detached conversion gives you full separation from the main house, which renters often prefer, but the utility runs are longer and grade changes between structures can add foundation and drainage scope. If the detached garage sits on a canyon-adjacent lot, we pull a geotechnical review before we finalize drawings. That review tells us whether your soil is expansive, whether undocumented fill is present, and whether deeper footings are required. Skipping this step is how a $180,000 quote becomes a $240,000 project mid-permit. Detached conversions in West Hills typically run $185,000-$260,000 all-in.

Carport Conversion

West Hills has a fair number of carports on the older ranch lots, and converting one into an ADU is possible but heavier on structural work than a garage conversion. Carports lack exterior walls, which means framing, sheathing, insulation, and weatherproofing all become new construction rather than retrofit. You’re also converting open space into enclosed living area, which triggers different LADBS energy compliance requirements. For West Hills homeowners weighing a carport conversion against a detached garage build, we typically recommend pricing both, because the gap is often smaller than expected once you factor in the carport’s existing slab and roof structure. Carport-to-ADU conversions in West Hills run $195,000-$275,000.

Trusted Brands We Service in West Hills

Ellery ADU Studio specifies and coordinates prefab and modular systems from Abodu, Cover, and Dvele within the same single contract that covers design, permitting, and construction. For West Hills homeowners, prefab makes particular sense on lots where the VHFHSZ requirements demand exacting fire-rated assemblies: these systems arrive with manufacturer-engineered details already documented, which can shorten the LADBS review cycle. We don’t just hand you a catalog. We size the system to your lot, coordinate the crane or flatbed access on West Hills streets, and manage the utility connections the factory doesn’t touch. When a prefab shell arrives, our crew handles the foundation, the panel upgrade if needed, and all on-site finishing under the same written price we quoted on day one.

Common Garage Conversion ADU Problems We See in West Hills Homes

• Failed VHFHSZ inspections on vent mesh and roof assembly. Contractors who frame to standard Valley specs get stopped at final when LADBS inspectors check for 1/16-inch ember-resistant mesh on eave and foundation vents and a full Class A roof assembly. The material swap and re-inspection can add $8,000-$18,000 and weeks to the schedule. We specify these items in the permit set on day one.
• Original 100-amp panel overload. The post-war ranches that dominate West Hills almost universally ship with 100-amp service. A new ADU’s heat pump, water heater, and induction cooktop will trip the main breaker after drywall is up if nobody ran a service load calculation first. We run that calculation before quoting, and the 200-amp upgrade is either priced in or flagged as a required line item.
• Hillside or canyon-adjacent lot surprises. Lots on the southern and western margins of West Hills sit in Santa Ana wind corridors and on soil that can be expansive or filled. Quoting a conversion without a geotechnical review is how a flat bid becomes a change-order-heavy job when deeper footings and revised structural drawings are required. We won’t quote those lots without the review.
• Garage slab assumptions. A 1960s West Hills garage slab wasn’t poured to support living space. We measure the slab thickness and check for moisture intrusion before we commit to a price. On a recent conversion we found a 4-inch slab, within range, but the previous owner had poured a non-structural extension that had to be cut back before footings could be placed.

Pricing for Garage Conversion ADU in West Hills, CA

We Also Serve Cities Near West Hills

Our crews serve Garage Conversion ADU in West Hills and the surrounding communities, including Canoga Park, Woodland Hills, Chatsworth, and Northridge. The fire-zone requirements we navigate daily in West Hills differ block by block even within the same zip code, and we bring that specificity to every project, whether your garage sits on the Valley floor or climbs into the foothills.

FAQs - Garage Conversion ADU in West Hills