ADU in Agoura Hills, CA
A Junior ADU & Interior Conversion in Agoura Hills typically runs $85,000-$165,000 all-in, while ADU Site Prep & Utilities add $15,000-$75,000 depending on hillside conditions and fire-zone requirements. Nearly every parcel here sits in a Very High Fire Hazard Severity Zone, so ignition-resistant construction and defensible-space compliance are built into every estimate we write. Call (820) 444-6584 for your free, written quote.
At Ellery ADU Studio, we’ve handled Junior ADU & Interior Conversion projects across Agoura Hills since our founding, and the 1970s-1990s housing stock here creates a predictable pattern: original 100-amp panels, galvanized plumbing, and oversized garages that look simple on paper but need serious infrastructure before they can legally house someone.
Why Agoura Hills Homes Are Different
Agoura Hills sits in the Santa Monica Mountains foothills, squarely inside the Diablo/Santa Ana wind corridor. After the 2018 Woolsey Fire burned through surrounding hillsides, the city tightened enforcement of Chapter 7A ignition-resistant standards. Every ADU here needs fire-rated roofing, ember-resistant vents, and specific exterior wall assemblies. Contractors working flatland Calabasas or Thousand Oaks don’t face this overlay.
The housing stock is mostly 1970s-1990s ranch and two-story tract homes on hillside and canyon-edge lots. Many have two- or three-car garages ripe for conversion, but original 100-amp electrical panels and aging copper or galvanized plumbing routinely require full upgrades. Sloped lots trigger soils reports and retaining-wall requirements that flat-lot builds avoid. LA County Fire audits defensible-space clearance at permit intake, and that review often surfaces unpermitted decks or sheds that must be removed before the ADU process moves forward.
Our Main Agoura Hills Services
Agoura Hills homeowners most often start with these three services, each with its own dedicated page.
ADU Design & Permitting in Agoura Hills
Our permit set is the core product, not an afterthought. In Agoura Hills, that means fire-zone documentation, defensible-space site plans, and Chapter 7A material specifications submitted complete the first time. We handle the LA County Fire audit at intake so you don’t face a surprise hold six weeks in. ADU Design & Permitting in Agoura Hills.
Garage Conversion ADU in Agoura Hills
Those oversized two- and three-car garages are ideal candidates, but we always verify slab thickness, panel amperage, and plumbing condition before quoting. A garage conversion ADU in Agoura Hills typically runs $120,000-$220,000 all-in when the infrastructure is sound. Garage Conversion ADU in Agoura Hills.
New Detached ADU in Agoura Hills
Detached units here face the full VHFHSZ requirement package plus hillside grading and drainage. We specify prefab systems from Cover, Dvele, or Mighty Buildings when the site allows, coordinated under our single contract. New Detached ADU in Agoura Hills.
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.
Junior ADU & Interior Conversion in Agoura Hills
A Junior ADU & Interior Conversion in Agoura Hills converts existing interior space - attached garages, basements, spare rooms, or above-garage areas - into permitted dwelling units under the owner’s primary residence. The 1970s-1990s housing stock here offers generous floor plans, but original systems and the VHFHSZ overlay mean every project needs fire-resistant assemblies and often a full electrical upgrade before we can submit. Junior ADU & Interior Conversion is our most called-about service in this city.
Room-to-ADU Conversion
Signs you need it
You have a ground-floor bedroom suite or wing with separate exterior access that sits unused, and you want rental income without new construction.
What it costs in Agoura Hills
Room-to-ADU conversions in Agoura Hills typically run $85,000-$145,000 all-in, including fire-rated separation, kitchenette, and dedicated meter where required.
How we do it
We verify the existing slab and framing can support residential loads, design the fire-rated separation assembly per Chapter 7A, produce the permit set, and build to the documented scope under our single contract.
Above-Garage ADU
Signs you need it
Your two-story garage has unfinished space above with headroom over 7 feet 6 inches and you want a separate rental unit without touching the main house.
What it costs in Agoura Hills
Above-garage ADUs in Agoura Hills typically run $110,000-$175,000 all-in, with fire-resistant exterior stairs and egress windows adding cost on hillside lots.
How we do it
We assess the garage framing and foundation for live loads, design the egress and fire-separation package, and coordinate the electrical service expansion with SCE.
What Junior ADU & Interior Conversion Costs in Agoura Hills
| Item | Typical range in Agoura Hills |
|---|---|
| Room-to-ADU conversion (all-in) | $85,000 - $145,000 |
| Above-garage ADU (all-in) | $110,000 - $175,000 |
| Electrical panel upgrade (200A) | $4,500 - $8,500 |
Does a Junior ADU need its own meter in Agoura Hills?
Not always - SCE allows sub-metering for Junior ADUs under 500 square feet, but we design for future separation. Call (820) 444-6584 and we’ll check your specific service.
Can I convert my basement in Agoura Hills?
Basement ADUs are rare here due to hillside drainage and egress requirements, but we evaluate each site individually. Call (820) 444-6584 for a free assessment.
ADU Site Prep & Utilities in Agoura Hills
ADU Site Prep & Utilities in Agoura Hills means grading, foundations, electrical service expansion, and utility extensions on hillside lots inside a Very High Fire Hazard Severity Zone. The 1970s-1990s housing stock here was built for single-family loads, so most ADU projects require infrastructure upgrades before construction can start. ADU Site Prep & Utilities is where hidden costs live, and where we document every line item upfront.
Electrical Panel Upgrade
Signs you need it
Your main panel is 100 amps, has no spare breaker spaces, or still uses a Zinsco or Federal Pacific enclosure.
What it costs in Agoura Hills
Electrical panel upgrades in Agoura Hills typically run $4,500-$8,500 for 200-amp service, including SCE coordination and permit.
How we do it
We verify load calculations for the ADU, specify the new panel and grounding per current code, pull the permit, and schedule SCE inspection.
Foundation & Grading
Signs you need it
Your lot slope exceeds 15 percent, the existing garage slab is cracked or under 4 inches thick, or soils reports are required at permit intake.
What it costs in Agoura Hills
Foundation and grading work in Agoura Hills typically runs $15,000-$45,000 for hillside retaining walls, drainage, and engineered fill.
How we do it
We engage a soils engineer, design the retaining and drainage package, excavate with erosion controls, and pour to the engineered spec.
What ADU Site Prep & Utilities Costs in Agoura Hills
| Item | Typical range in Agoura Hills |
|---|---|
| Electrical panel upgrade (200A) | $4,500 - $8,500 |
| Foundation & grading (hillside) | $15,000 - $45,000 |
| Plumbing lateral extension | $3,500 - $12,000 |
Will SCE require a service upgrade for my ADU?
Most 100-amp panels in Agoura Hills cannot handle an ADU load - we verify during our first site visit and include the upgrade in your written quote. Call (820) 444-6584 to schedule.
Do I need a soils report for a garage conversion?
Only if the garage sits on fill or the slope exceeds 15 percent - we flag this at intake so it doesn’t surprise you mid-permit. Call (820) 444-6584 for a free evaluation.
Brands We Service in Agoura Hills
We specify and coordinate prefab and modular systems from Cover, Dvele, Mighty Buildings, and Boxabl within our single contract, with parts and technical documentation stocked locally through our Los Angeles office. Most brand-specific coordination questions are resolved same-day. See our brands for full specifications.
Pricing for ADU in Agoura Hills, CA
| Service | Typical range in Agoura Hills |
|---|---|
| Room-to-ADU conversion | $85,000 - $145,000 |
| Above-garage ADU | $110,000 - $175,000 |
| Garage conversion ADU | $120,000 - $220,000 |
| New detached ADU | $180,000 - $350,000 |
| Junior ADU (JADU) | $65,000 - $115,000 |
| Electrical panel upgrade | $4,500 - $8,500 |
| Foundation & grading | $15,000 - $45,000 |
| Plumbing lateral extension | $3,500 - $12,000 |
| Gas line extension | $2,500 - $8,000 |
| Landscaping & hardscape (defensible space) | $5,000 - $18,000 |
What pushes price up in Agoura Hills: hillside retaining walls, Chapter 7A fire-resistant materials, and unpermitted structures found during defensible-space review. Under Haven Standard Clause 1, every project is quoted with a written price before any work begins - no call-for-pricing, no change orders without signed amendment.
Neighborhoods We Serve in Agoura Hills
We work across Agoura Hills, from the canyon-edge properties off Kanan Road to the ranch-style tracts near Reyes Adobe. Dispatch and scheduling are coordinated from our Los Angeles office; crews serve Agoura Hills locally with next-day availability for estimates.
- Old Agoura
- Malibu Junction
- Reyes Adobe
- Forest Cove
- Morrison Ranch
Service Area - Cities Near Agoura Hills
Our crews work throughout the western San Fernando Valley and Ventura County corridor. We also serve Calabasas, CA, Thousand Oaks, CA, West Hills, CA, and Simi Valley, CA with the same single-contract design-build model and written upfront pricing.
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 About ADU in Agoura Hills
Typically 4-6 months for a complete submittal, longer if defensible-space review surfaces unpermitted structures. We document the site plan with clearance measurements before filing to avoid that delay.
California law overrides HOA bans on ADUs, but design guidelines and architectural review still apply. We produce the documentation your HOA requires alongside the city permit set.
Chapter 7A materials and defensible-space compliance typically add 8-15 percent to a comparable non-VHFHSZ build. We itemize this in your written quote so you see the exact impact before signing.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Agoura Hills Customers Say
"Every allowance was itemised at the start, so the finish selections did not turn into a surprise at the end."
- Benedict H."The permit set and the build were one contract with one number. Our neighbours used two firms and spent a year watching them blame each other."
- Helena V."They walked us through setbacks and utility capacity before we paid anything, and told us one of our two options was not going to get approved."
- Mireille T.