Fast, Reliable Garage Conversion ADU Across Agoura Hills
A garage conversion ADU in Agoura Hills typically runs $125,000-$195,000 all-in, from measured drawings through final county inspection, and most projects move from signed contract to permit submittal in 6-10 weeks. Because Agoura Hills contracts with LA County Public Works Building & Safety rather than operating its own building department, your permit routes through the Calabasas district office, where plan checkers apply both state ADU law and a Wildland-Urban Interface fire-hardening overlay that doesn’t exist in city-run jurisdictions like neighboring Thousand Oaks. We know this county process. Our Garage Conversion ADU team has routed dozens of Agoura Hills projects through the Calabasas office, and we scope the fire-resistive compliance report, the panel upgrade, and the drainage plan before we quote, not after. Call (805) 301-9518 to schedule your free estimate.
Why Ellery ADU Studio Camarillo Is Agoura Hills’s Preferred Garage Conversion ADU Company
We’ve designed, permitted, and built garage conversion ADUs across Agoura Hills since 2015 - the year California’s ADU laws shifted - and our dispatch and scheduling are coordinated from our Los Angeles office with crews serving Agoura Hills locally. Our 900+ ADU projects statewide include conversions in Old Agoura, Morrison Ranch, and the hillside tracts off Kanan Road, where county WUI requirements and 100-foot defensible-space rules are routine scope items for us, not surprises for the homeowner.
Our Agoura Hills clients receive what every Ellery 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 before construction begins. We don’t ask you to trust us. We document what we find, quote what we scope, and warrant what we build.
A live person answers our phones 24/7. If you already have a written estimate from another firm, we’ll provide a Free Second Opinion, line item by line item.
Our Garage Conversion ADU Services in Agoura Hills
Attached Garage Conversion
Attached garage conversions are the most common ADU we permit in Agoura Hills. The 1970s-1990s tract housing stock here - ranch and California contemporary homes on 7,000-15,000 square foot lots - typically includes a two-car garage sharing a wall with the main house. That shared wall simplifies utility tie-ins but complicates fire separation: the county requires a one-hour rated assembly between dwelling units, and in Agoura Hills’s High Fire Hazard Severity Zone, that assembly must also meet Chapter 7A ignition-resistant standards with ember-resistant vents. We specify the wall type, the vent model, and the compliance report in our permit set before we quote. A typical attached garage conversion in Agoura Hills runs $125,000-$165,000 all-in.
Detached Garage Conversion
Detached garage conversions in Agoura Hills face a constraint that flatland cities don’t: the 100-foot defensible-space rule. If your detached garage sits on a slope or near a hillside, county staff will measure the clearance zone before approving siting. We’ve seen detached conversions rejected because a slab was poured without a grading plan, pushing drainage toward the slope or leaving the structure inside the clearance zone. We survey the drainage pattern and the defensible-space envelope before we draw. Detached conversions here typically run $140,000-$195,000, with grading and drainage work scoped separately if needed.
Garage JADU
A Junior ADU - a garage conversion of 500 square feet or less, owner-occupied, with efficiency kitchen and no separate utility meter - can be the right tool for Agoura Hills homeowners who want rental income without the full cost of a standalone ADU. The county applies the same Chapter 7A fire-hardening to JADUs as to full ADUs, so the ember-resistant vents and one-hour wall assembly still apply. But the smaller footprint and shared utilities reduce the scope. Typical Garage JADU projects in Agoura Hills run $95,000-$135,000. On a 1980s tract house off Kanan Road in Old Agoura, we converted an attached two-car garage where the original 100-amp panel and slab-on-grade stem walls wouldn’t support the planned kitchenette and bath load, so we coordinated a panel upgrade and a one-hour wall assembly with Chapter 7A ember-resistant vents before the county plan check. Because the lot backs onto a 100-foot defensible-space slope, we repositioned the garage’s west-facing window and re-graded the apron so drainage ran away from the new living space. The county accepted the package with a fire-resistive compliance report attached, and the conversion closed out as a permitted JADU.
Garage Partition & Bathroom Add
Some Agoura Hills homeowners don’t need a full ADU - they need a conditioned workshop, a guest suite, or a bathroom added to an existing garage space. We still permit these as habitable space, which means the county still checks Chapter 7A compliance on any new exterior wall, roof, or vent penetration. The scope is smaller, but the documentation standard is identical. We quote these as fixed-scope projects with a written price, typically $45,000-$85,000 depending on whether we’re adding a sewer lateral, upgrading electrical, or both.
Carport Conversion
Carport conversions in Agoura Hills require full enclosure, which triggers the same WUI fire-hardening as a garage conversion plus new foundation work where posts previously sat. The county will want to see how the new slab ties to existing drainage and whether the enclosed volume sits within the defensible-space zone. We scope the foundation, the enclosure assembly, and the compliance report as a single package.
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 Coordinate in Agoura Hills
Ellery specifies and coordinates prefab and modular systems from Abodu, Cover, and Dvele within the same single-contract design-build model we apply to site-built work. For Agoura Hills garage conversions that include exterior cladding replacement - common when a garage door opening is infilled with a wall assembly - we often specify James Hardie fiber-cement products for their Chapter 7A ignition-resistant rating and their compatibility with the one-hour wall assemblies county plan checkers expect. Every material choice is documented in the permit set, not decided in the field.
Common Garage Conversion ADU Problems We See in Agoura Hills Homes
- County plan check rejects the submittal as incomplete because no fire-resistive construction compliance report was filed. The Calabasas district office requires a CCR documenting Chapter 7A compliance for every wall, roof, and vent assembly in the WUI zone. City-permitted neighbors in Thousand Oaks skip this step. We file the CCR with the initial submittal, not after rejection.
- Original 100-amp panel and older slab-on-grade footings can’t carry the added load. A kitchenette, bathroom, and mini-split draw more than a garage door opener and a few outlets. We verify panel capacity and slab condition during our initial site visit, and we scope the upgrade in the written quote - not as a change order after permit.
- Detached garage conversions fail defensible-space or drainage review. A slab poured without a grading plan can push runoff toward a slope or leave the structure inside the 100-foot clearance zone. We survey before we draw, and we coordinate with a grading engineer when the site requires it.
- Santa Ana wind exposure and summer heat loads are underestimated in mechanical design. South- and west-facing hillside garages in Agoura Hills see interior temperatures above 95°F without proper attic ventilation and correctly sized HVAC. We size mechanical systems for the actual heat load, not the square footage alone.
Pricing for Garage Conversion ADU in Agoura Hills, CA
| Project Type | Typical Range (All-In) |
|---|---|
| Garage JADU (attached, ≤500 sq ft) | $95,000 - $135,000 |
| Attached Garage Conversion (full ADU) | $125,000 - $165,000 |
| Detached Garage Conversion | $140,000 - $195,000 |
| Garage Partition & Bathroom Add | $45,000 - $85,000 |
| Carport Conversion | $110,000 - $160,000 |
These ranges include measured as-built drawings, the full permit set, all county fees, construction, and final inspection. What moves a project toward the high end: panel upgrades, foundation work, grading and drainage plans, and hillside access constraints that limit equipment staging. Every project receives a written line-item quote before any work starts - Haven Standard Clause 1 - and the scope is locked at signing under Clause 5 (No Surprises). No door-side upsells. No scope creep. Call (805) 301-9518 for your exact quote; estimates are free.
We Also Serve Cities Near Agoura Hills
Our crews work throughout the western San Fernando Valley and Ventura County corridor, including Garage Conversion ADU in Agoura Hills and neighboring Westlake Village, Oak Park, Calabasas, and Thousand Oaks. Each city has its own permitting authority and fire-zone overlay, and we scope accordingly - county process for Agoura Hills and Calabasas, city process for Thousand Oaks and Westlake Village.
Serving Agoura Hills, CA - Our Local Coverage Area
We’re based in the Agoura 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 Agoura Hills
Yes. Because Agoura Hills sits almost entirely in a High or Very High Fire Hazard Severity Zone and contracts with LA County Building & Safety, every garage conversion ADU requires a CCR documenting Chapter 7A compliance for exterior walls, roof assemblies, and vents. We prepare and file this report with your initial permit submittal. Call (805) 301-9518 to confirm your property’s FHSZ status and scope the compliance work.
The county’s WUI overlay adds material and documentation costs that Thousand Oaks’s city-run building department does not require: ember-resistant vents, Class A roofing, one-hour exterior wall ratings, and the fire-resistive compliance report itself. Site conditions in Agoura Hills - hillside drainage, defensible-space constraints, and older electrical panels - also drive scope. We itemize these differences in your written quote so you see exactly what you’re paying for. Call (805) 301-9518 for a line-item breakdown.
Yes, if the garage is attached to your primary residence, the converted space will not exceed 500 square feet, and you commit to owner occupancy of either the main house or the JADU. The county still applies Chapter 7A fire-hardening, but the smaller footprint and shared utilities reduce cost. Typical Garage JADU projects in Agoura Hills run $95,000-$135,000. Call (805) 301-9518 to assess whether your garage qualifies.
If your garage sits on or near a hillside, county staff will verify that the structure and any new landscaping remain outside the 100-foot clearance zone required by state defensible-space law. For detached garages, this can constrain siting and require re-grading. We survey the clearance envelope and drainage pattern during our initial site visit and coordinate with a grading engineer when needed. Call (805) 301-9518 to schedule that survey.
The original slab-on-grade footings in 1970s-1990s Agoura Hills tracts were sized for vehicle loads, not habitable space with a kitchen and bath. The stem walls may need reinforcement. Original electrical panels - often 100-amp - can’t support the added circuits for HVAC, kitchen appliances, and bathroom GFCI outlets. We inspect both during our first visit, document what we find with photos, and scope any upgrades in your written quote. Call (805) 301-9518 to schedule that inspection; estimates are free.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Agoura Hills since 2015.