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
Most ADU projects in Calabasas run $180,000 – $320,000 for a detached unit before site work, and the city’s hillside lots, HOA overlays, and strict hillside-grading rules mean the right builder matters more here than almost anywhere in the San Fernando Valley. We’re Sutton ADU Builders, and we give Calabasas homeowners a written price before any work starts, plus a 365-Day Done Right Promise in writing. If you’re weighing an ADU, garage conversion, or room addition in Calabasas, call (472) 248-8213 and we’ll walk you through what your specific lot will actually require.
Why Calabasas Homes Are Different
Calabasas isn’t one housing market; it’s several stacked on top of each other. The Oaks and guard-gated communities like Mountain View Estates run on HOA architectural review that can add 30 – 60 days before permits even start. Older ranch-style homes off Mulholland Highway and Las Virgenes Road often sit on lots with meaningful slope, which changes foundation design and can add $15,000 – $40,000 in grading and retaining work before a single wall goes up. The climate plays a role too: Calabasas sits against the Santa Monica Mountains, so summer heat and Santa Ana wind exposure affect insulation choices, window placement, and exterior materials. We look at fire-hardening requirements in hillside zones, because Calabasas Fire Department and LA County now require specific eave, vent, and siding details in wildfire-risk areas. Homes near Lake Calabasas and Hidden Hills-adjacent streets often have mature oaks with protected root zones, which can shift where an ADU can legally sit. None of this is impossible. It just means the plan has to respect the lot before the estimate means anything.
Our Main Calabasas Services
Most Calabasas homeowners call us about one of three things: adding square footage to the existing house, building a separate ADU in the yard, or converting underused interior space into a proper room. Here’s how each one works in Calabasas.
Home Addition Contractor in Calabasas
A home addition in Calabasas usually means extending the footprint of the main house, often for a larger kitchen, a primary suite, or a second living area. On flat lots in neighborhoods like Calabasas Park, the foundation and framing move quickly. On hillside lots off Stunt Road or Piuma Road, the same addition needs pier work and possibly retaining walls, which changes both cost and schedule. We walk the lot, check the setback (the required gap between your new structure and the property line), and give you a written number before any work begins. Home Addition Contractor in Calabasas
ADU Builders in Calabasas
Detached ADUs in Calabasas are common on larger lots, especially in areas where the main house is close to the property line and a garage conversion isn’t possible. We work with prefab and modular lines like Abodu, Cover, and Dvele, which can shorten the on-site build time considerably, and we also handle stick-built ADUs where a custom footprint is needed. Calabasas hillside grading and HOA review are the two variables that most affect schedule here, and we’ll give you a straight answer on both before you commit. ADU Builders in Calabasas
Room Addition Contractor in Calabasas
A room addition in Calabasas often means converting a garage, attic, or underused bonus space into a bedroom, office, or rental-ready suite without changing the home’s footprint. These projects tend to move faster than additions because the shell already exists, but Calabasas homes built in the 1970s and 1980s often need electrical panel upgrades and insulation brought to current code. We’ll tell you exactly what your existing structure needs before quoting, and the price we give you is the price on paper. Room Addition Contractor in Calabasas
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 with several ADU product lines Calabasas homeowners ask about most, including Abodu, Cover, and Dvele. We handle the site prep, foundation, utility connections, and finish work for these systems, and we can source parts locally to keep the schedule moving. See our brands page for the full list.
Pricing for ADU Company in Calabasas, CA
| Service | Typical range in Calabasas |
|---|---|
| Detached ADU (400 – 600 sq ft, prefab) | $180,000 – $260,000 |
| Detached ADU (600 – 900 sq ft, stick-built) | $260,000 – $320,000 |
| Garage conversion to ADU | $120,000 – $180,000 |
| Room addition (200 – 400 sq ft) | $90,000 – $150,000 |
| Primary suite addition (400 – 600 sq ft) | $160,000 – $240,000 |
| Foundation and site prep (hillside lots) | $15,000 – $40,000 additional |
| HOA review and architectural submission support | $2,500 – $6,000 |
| Electrical panel upgrade (if required) | $3,500 – $7,000 |
Hillside grading, retaining walls, and HOA-mandated material changes are the three things that most often push a Calabasas quote upward. Every price we give is written down before work starts, so what you approve is what you pay. Call (472) 248-8213 for a free estimate on your specific lot.
Neighborhoods We Serve in Calabasas
We work across Calabasas, from the guard-gated communities to the older hillside streets and the flat lots near the 101. Typical response time for an estimate visit in Calabasas is within 2 – 4 business days.
- The Oaks of Calabasas
- Calabasas Park
- Mountain View Estates
- Mulholland Highway corridor
- Las Virgenes Road area
Service Area – Cities Near Calabasas
If you’re close to Calabasas but across a city line, we can help there too. We serve Woodland Hills, CA, West Hills, CA, Topanga, CA, and Canoga Park, CA with the same written-price and 365-Day Promise standard. When you call, we’ll confirm which location handles your address.
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 projects move from signed agreement to permit submission within 2 – 4 weeks, depending on HOA architectural review and site access. A hillside lot with grading questions will take longer than a flat Calabasas Park lot. Call (472) 248-8213 and we’ll give you a realistic schedule for your address.
Yes. Calabasas has HOA communities with their own architectural standards, and we prepare the drawings, submittals, and documentation they require. We also coordinate city permits and inspections. The goal is one written number that reflects the full permitting path, so nothing surprises you later.
We serve Calabasas, Hidden Hills-adjacent streets, and the surrounding cities including Woodland Hills, West Hills, Topanga, and Canoga Park. If you’re not sure whether your home falls in our service area, call (472) 248-8213 and we’ll confirm in about two minutes.
If you’re considering an ADU, room addition, or full home addition in Calabasas, the next step is simple: call (472) 248-8213 for a free estimate. We’ll give you our honest read on your lot, a written price, and a real person to talk to every time you call.
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
"Backyard ADU for my mother. The project manager showed ID and walked me through the permit steps, the foundation plan, and the schedule. Moved her in on time."
- Margaret C."Insulated the walls and ceiling properly. It stays comfortable even in July."
- Tamika W."They handled the drawings and the permit paperwork for us. All I had to do was pick the finishes."
- Rosa M.
