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.
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.
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.
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
Here are honest, current ranges for West Hills, inclusive of design, permit set, construction, and LADBS close-out, but before any site-specific geotechnical or panel surprises are priced in because we identify those before quoting:
| Conversion Type | Typical West Hills Range | What Moves the Number |
|---|---|---|
| Attached Garage Conversion | $155,000-$225,000 | Panel upgrade, fire-zone venting, finish level |
| Garage Partition & Bathroom Add | $135,000-$195,000 | Bathroom scope, fire-rated separation detail |
| Detached Garage Conversion | $185,000-$260,000 | Utility run length, geotechnical review, grading |
| Carport Conversion | $195,000-$275,000 | Full wall construction, energy compliance, slab condition |
Every quote we issue in West Hills is a written price under Haven Standard Clause 1: no door-side upsells, no scope creep, no “we discovered something” letter three weeks in. If we missed something in our own review, that’s our cost, not yours. Call (971) 497-2402 for a written quote. If you already have an estimate from another firm, bring it in and we’ll review it line by line at no charge.
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.
Serving West Hills, CA - Our Local Coverage Area
We’re based in the West Hills 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 West Hills
Yes, if your garage sits inside the VHFHSZ that covers much of West Hills, LADBS requires a full Class A roof assembly regardless of the current roof’s condition. A roof that looks fine can still be a composition shingle assembly rated lower than Class A, and the inspector will check at final. This means the roof line item on a West Hills garage conversion is often $10,000-$18,000 higher than the same conversion in Canoga Park because the entire assembly, not just the top layer, must meet Class A. We confirm your parcel’s fire-zone status in the first week so this is priced from the start, not discovered at inspection. Call (971) 497-2402 for an exact quote on your specific garage.
Almost never. A kitchenette with an induction cooktop, a mini-split heat pump, and a tankless water heater will draw more than a 100-amp panel can safely supply alongside the main house’s existing load. We run a service load calculation on every West Hills project before we quote, and the 200-amp upgrade is priced as a required line item when we know it’s needed, typically $4,000-$6,500 depending on the service drop location. Skipping this calc is how you trip the main breaker after drywall is up. Call (971) 497-2402 and we’ll check your panel and meter before you spend a dollar on drawings.
The wind corridors are exactly why the VHFHSZ designation exists here. Santa Ana winds push embers miles ahead of a fire front, and those embers enter homes through eave and foundation vents. That’s why LADBS requires 1/16-inch ember-resistant mesh on every vent in a new ADU within the zone. The requirement applies regardless of whether your house has burned or ever will: it’s a building code requirement, not a risk assessment. On one West Hills conversion, the inspector flagged our foundation vents until we swapped the standard screens for the 1/16-inch mesh, and the final sign-off came the same day. We specify the mesh in the permit set so the inspector sees it on paper before they see it in person. Call (971) 497-2402 to confirm whether your parcel is in the zone.
A geotechnical investigation. Canyon-adjacent lots in West Hills sit on soil that LADBS will not accept on a standard foundation detail, because the hillside can contain expansive clay, undocumented fill, or both. The geotech report tells the structural engineer what the soil will support and whether deeper footings, pier support, or a revised foundation design is required. This review typically costs $3,500-$7,000 and adds 2-4 weeks before permit application. We won’t quote a hillside West Hills garage conversion without it, because a quote built on assumptions is a change order waiting to happen. Call (971) 497-2402 and we’ll tell you whether your specific lot triggers the review.
Yes. A partition conversion is one of the more common requests we get from West Hills homeowners on the larger ranch lots, where the garage doubles as a workshop or storage for equipment. We frame a fire-rated separation wall between the ADU and the remaining garage space, give the ADU its own entry, panel circuit, water heater, and HVAC, and keep your workshop side functional throughout construction. The ADU portion must still meet every VHFHSZ requirement, including ember-resistant venting and the Class A roof if your parcel is in the zone. Partition conversions with a full bath in West Hills run $135,000-$195,000. Call (971) 497-2402 for a written quote on your specific layout.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving West Hills since 2015.