







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Chatsworth, CA
Fielding ADU Builders handles ADU construction, garage conversions, and room additions in Chatsworth, CA, with a written price before any work starts. Chatsworth’s mix of 1950s and 1960s ranch homes, larger horse-property lots south of the 118, and newer hillside builds north of Devonshire means most projects need real attention to grading, setbacks, and how the structure sits on the land. If you’re weighing an ADU in Chatsworth, call (361) 315-4177 and we’ll walk you through what your lot can support.
Why Chatsworth Homes Are Different

Chatsworth is one of the hotter, drier corners of the San Fernando Valley. Summer temperatures routinely push past 100 degrees, which changes how we detail insulation, roof venting, and window placement on any attached or detached addition. A poorly vented Chatsworth ADU becomes an oven by July; we size HVAC and eave overhangs for that reality, not for a generic Southern California average.
The housing stock splits roughly three ways. South of Devonshire and east of Topanga Canyon, you’re working with mid-century ranch layouts, often on flat pads with mature trees. West toward the Santa Susana Pass and north into the hills, lots get steeper, retaining walls enter the picture, and the city’s hillside grading rules apply. Some neighborhoods, especially around the Chatsworth Reservoir area and the equestrian-zoned pockets, carry extra conditions: horse-keeping easements, larger side-yard separations, and sometimes HOA architectural review. That changes the timeline and the paperwork. We account for it before the price goes in writing.
Our Main Chatsworth Services
Three services drive most of the calls we get from Chatsworth homeowners: room additions, garage conversions, and full ADU construction. Each has its own dedicated Chatsworth page below.
Room Addition Contractor in Chatsworth
Adding square footage to an existing Chatsworth home usually means extending a rear or side elevation while keeping the original roofline functional. On many of the ranch footprints around Mason Avenue and Lassen Street, the addition ties into older framing, so we spend time at the start verifying what’s behind the stucco. Foundation condition, ceiling height, and how the existing electrical panel is loaded all get checked before the price is set. Room Addition Contractor in Chatsworth page covers scopes, timelines, and what a rear extension typically costs in this market.

Garage Conversion Contractor in Chatsworth
Chatsworth garages from the 1960s and 1970s were built for two cars and a workbench, not for human occupancy. Converting one into a rental unit or in-law suite means upgrading the slab, adding insulation to walls that never had any, and often replacing a flat roof that’s been baking in Valley heat for 50 years. The city also requires bringing the conversion fully into current residential code, including egress windows and fire separation from the main house. Garage Conversion Contractor in Chatsworth covers the process in detail.

ADU Builders in Chatsworth
Backyard ADUs in Chatsworth range from prefab units placed with a crane to stick-built detached structures on hillside lots. The prefab path, using brands we service like Abodu and Cover, works well on flat pads; the conventional path gives more flexibility when the grade is uneven or the access is tight. Lot coverage, setback variance, and utility trenching all vary by parcel. ADU Builders in Chatsworth has the full scope, including what to expect on a hillside lot.

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 Chatsworth
We service ADU platforms from Abodu, Cover, and Dvele, along with conventional builds using James Hardie siding. Parts for these systems are ordered direct from the manufacturer and staged at our Los Angeles office before delivery to your Chatsworth site. See our brands page for the full list and what each platform does best.
Pricing for ADU Company in Chatsworth, CA
Below are the ranges we typically quote in Chatsworth before permit fees. These are working numbers based on current labor and material costs in the northwest Valley, not national averages.
| Service | Typical range in Chatsworth |
|---|---|
| Detached ADU (prefab, 400 – 600 sq ft) | $180,000 – $300,000 |
| Detached ADU (stick-built, 400 – 600 sq ft) | $220,000 – $380,000 |
| Detached ADU (stick-built, 600 – 800 sq ft) | $290,000 – $450,000 |
| Detached ADU (stick-built, 800 – 1,000 sq ft) | $370,000 – $560,000 |
| Attached ADU (junior unit, converted space) | $110,000 – $210,000 |
| Garage conversion (finished ADU, 400 – 500 sq ft) | $130,000 – $210,000 |
| Garage conversion (new garage + ADU above) | $260,000 – $380,000 |
| Room addition (ground-floor extension, 250 – 400 sq ft) | $90,000 – $160,000 |
| Room addition (second-story, 400 – 600 sq ft) | $160,000 – $280,000 |
| Room addition (primary suite, 300 – 450 sq ft) | $130,000 – $220,000 |
Hillside lots north of the 118 reliably push the upper end of these ranges: retaining walls, deeper footings, and longer utility runs all add cost. Whatever the number ends up being, it goes in writing before any work starts. The price you approve on day one is the price on the final invoice.
Neighborhoods We Serve in Chatsworth

We work across all of Chatsworth, from the flatter ranch-home pockets south of Devonshire to the hillside parcels near the Santa Susana Pass. Our crews arrive from the Los Angeles office and cover the full Chatsworth zip code.
- Chatsworth West (west of Topanga Canyon)
- Chatsworth North (hillside lots north of the 118)
- Devonshire Corridor (central Chatsworth)
- Chatsworth Lake area (near the reservoir)
- Mason Avenue corridor (east Chatsworth)
Most estimates in Chatsworth are scheduled within a few business days of your call. Site visits for hillside parcels may take a little longer to arrange because we line up survey and grading review before we walk the property.
Service Area – Cities Near Chatsworth
Beyond Chatsworth, our crews cover neighboring communities in the northwest Valley and along the 118 corridor. If your property is in Porter Ranch, CA, Northridge, CA, Canoga Park, CA, or Reseda, CA, we can handle the same scope of work with the same written-price policy. Each city has its own page with local conditions and pricing details.
Serving Chatsworth, CA - Our Local Coverage Area
We’re based in the Chatsworth 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 Chatsworth

Most Chatsworth projects move from signed contract to first day of work within 6 to 10 weeks, depending on permit queue and whether the parcel needs hillside or grading review. Prefab ADUs from Abodu or Cover can shorten that window because the unit is fabricated off-site while site work proceeds. Call (361) 315-4177 to get a realistic timeline for your specific lot.
If your Chatsworth home sits in an HOA, you’ll typically need architectural committee approval before the city will issue permits, especially in the gated communities north of the 118. We prepare the submittal package, but the HOA review clock is outside our control. Budget an extra 3 to 6 weeks if your community requires it.
Yes, we cover the full Chatsworth zip code, including hillside parcels near the Santa Susana Pass and the equestrian-zoned areas. For hillside work, we bring in a grading and drainage review before pricing so the written quote reflects the actual site conditions, not a flat-lot assumption. Call (361) 315-4177 for a free estimate.
Reed Calloway leads Fielding ADU Builders. Every project gets a written price before work begins, and every project is backed by the Garrison Standard: a one-year written guarantee covering workmanship defects. If something fails inside that year, we come back and fix it at no charge. Call (361) 315-4177 to schedule your free estimate in Chatsworth.
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 Chatsworth Customers Say
"Garage conversion with a new bath and kitchenette. Permit was handled by them. Inspection passed first time."
- Sheila B."Honest feedback on what the lot could fit. Told me up front what would fit on the lot and what the setbacks would allow."
- Rita C."Clear price breakdown. Change orders were all in writing."
- Hal P.



