A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Calabasas, CA
An ADU in Calabasas is a different project than an ADU in most of Los Angeles County. The hillside lots, oak tree protections, HOA design rules, and fire-zone requirements shape everything: where the unit can sit, how the foundation gets engineered, what materials the city will approve, and what the final number on the written estimate looks like. We’re Seedling ADU Builders, and we work with Calabasas families on attached and detached ADUs, garage conversions, and home additions that have to clear a higher bar than most. If you’re trying to figure out what’s possible on your lot, call us at (805) 309-3462 for a free estimate and we’ll walk through it with you.
Why Calabasas Homes Are Different
Calabasas stacks several layers of constraint onto any ADU. First is the terrain. In hillside neighborhoods like Mulholland Heights, foundation work often means drilling into bedrock or designing for expansive soils that move with the seasons. That’s a geotechnical conversation before it’s a floor-plan conversation. In flatter communities like Calabasas Park and The Oaks, the constraints are quieter but real: HOA aesthetic standards, dark-sky lighting rules that require shielded low-lumen exterior fixtures, and oak tree ordinances that can limit where a structure can go at all.
The housing stock matters too. Many Calabasas homes were built between the 1980s and early 2000s, and a good number of them need seismic retrofitting or electrical panel upgrades before an attached ADU or garage conversion can pass inspection. The hot, dry summers near the Santa Monica Mountains mean the city and the fire marshal both care about fire-resistant siding, defensible space, and HVAC that’s actually sized for the unit. None of this is impossible. It just means the plan has to be specific from the first conversation, and the written price has to account for it honestly.
Our Main Calabasas Services
These are the three projects Calabasas homeowners call us about most often. Each one has its own page with local pricing and a closer look at what the job involves.
Home Addition Contractor in Calabasas
Home additions in Calabasas frequently land on hillside lots where the foundation has to be engineered for slope stability before framing can begin. We handle attached and detached additions, from a new primary suite to a full second-story build, and we coordinate the geotechnical work, city submittals, and fire-resistant material choices that Calabasas requires. Every addition starts with a written price, and the crew that shows up is background-checked and in uniform, with shoe covers and drop cloths standard inside your home. See Home Addition Contractor in Calabasas for full pricing and what to expect.
Garage Conversion Contractor in Calabasas
Garage conversions are often the fastest path to a rental unit or in-law suite on a flat Calabasas lot, but plenty of older garages hide surprises: undersized footings, outdated electrical, or a roof that wasn’t built to carry a conditioned space. We open the walls, tell you exactly what’s there, and give you a written price before work starts. In neighborhoods under HOA review, we also handle the aesthetic requirements so the conversion reads as part of the original house. Learn more on our Garage Conversion Contractor in Calabasas page.
ADU Builders in Calabasas
A detached ADU in Calabasas is a new home on your lot, and it deserves to be treated that way. We build site-constructed units and also work with prefab brands like Abodu, Cover, and Dvele where the lot and the city approval path make factory-built a smarter choice. Whether you’re planning a one-bedroom rental or a two-bedroom unit for family, the process starts with a written price and ends with the 365-Day Done Right Promise: if it’s not done right, we make it right. Details are on the ADU Builders in Calabasas page.
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.
Brands We Service in Calabasas
We work regularly with the prefab and panelized brands serious ADU buyers in Calabasas research before calling anyone: Abodu, Cover, and Dvele for factory-built units, plus James Hardie siding and trim where fire-resistant exterior materials are required. For a closer look at what each brand offers and how they compare, see our brands.
Pricing for ADU Company in Calabasas, CA
| Service | Typical range in Calabasas |
|---|---|
| Detached ADU (studio, site-built) | $165,000 – $235,000 |
| Detached ADU (1-bedroom, site-built) | $210,000 – $310,000 |
| Detached ADU (2-bedroom, site-built) | $260,000 – $390,000 |
| Attached ADU (permitted interior conversion) | $110,000 – $175,000 |
| Garage conversion (studio, finished) | $95,000 – $160,000 |
| Garage conversion (1-bedroom, finished) | $125,000 – $195,000 |
| Prefab ADU (studio, delivered and set) | $135,000 – $210,000 |
| Prefab ADU (1-bedroom, delivered and set) | $175,000 – $265,000 |
| Prefab ADU (2-bedroom, delivered and set) | $225,000 – $340,000 |
| Seismic retrofit (foundation bolting and bracing) | $4,000 – $12,000 |
| Electrical panel upgrade (200A, permit included) | $3,500 – $6,500 |
In Calabasas, the biggest price movers are hillside foundation work, oak tree mitigation, fire-resistant material upgrades, and HOA design review. Those are real costs, and the right time to learn about them is before you commit, not after the crew arrives. Every Seedling project in Calabasas gets a written price before any work starts, with no surprise line items added later.
Neighborhoods We Serve in Calabasas
We serve Calabasas neighborhoods from the hillsides along Mulholland Drive down to the flatter streets of Calabasas Park and The Oaks. Crews arrive on schedule and work clean, so your yard and driveway don’t look like a staging area during the build.
- Mulholland Heights
- Calabasas Park
- The Oaks
- Calabasas Hills
- Old Topanga
Service Area – Cities Near Calabasas
Our team serves Calabasas and the surrounding communities across the western San Fernando Valley and Santa Monica Mountains. If you’re in West Hills, CA, Topanga, CA, Canoga Park, CA, or Agoura Hills, CA, we can help with your ADU, garage conversion, or addition and give you the same written-price process.
Serving Calabasas, CA - Our Local Coverage Area
We’re based in the Calabasas 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 Company in Calabasas
Most Calabasas ADUs take 6 to 10 months from first conversation to final inspection. Hillside foundation work, geotechnical review, oak tree reports, and HOA approval can all add weeks. We’ll give you a written timeline with your written price so you can plan around it.
If your home is in a community like The Oaks or Calabasas Park, you’ll likely need design review from your HOA before the city permit is issued. We prepare the elevation drawings, material samples, and lighting specs the board asks for, and we build that step into the schedule and the price.
Yes. We coordinate the geotechnical work, foundation design, and fire-resistant material selection that hillside and wildfire-zone lots in Calabasas require. It’s part of our standard process, not an add-on, and it’s included in the written estimate from the start. Call (805) 309-3462 to schedule a free estimate and we’ll review your specific lot.
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 Calabasas Customers Say
"Built a backyard unit for us. For a months long project the crew kept the site remarkably tidy, swept daily, and were respectful of our neighbors and our dog. Beautiful result."
- Charlotte Vey"They converted our garage and were so mindful that we were living right there through it. Quiet hours respected, site swept, nothing left out where the kids play. Lovely work."
- Eugene Park"Quality ADU. Communication was good overall, with one quiet stretch during the inspection wait where I had to check in. Once moving again they were tidy and quick to finish."
- Noelle Friedman
