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
Benson ADU Builders handles accessory dwelling units, home additions, and room additions across Chatsworth, CA. Most of the homes here were built between the 1950s and 1980s, which means flat lots, generous setbacks, and floor plans that actually make sense to extend. The big local variables are the heat, the clay-heavy soil, and a patchwork of hillside and flatland parcels that change how we approach foundation work and grading. Call (903) 568-7222 to talk through what’s possible on your lot.
Why Chatsworth Homes Are Different
Chatsworth sits at the far northwest corner of the San Fernando Valley, and the terrain shifts fast. Homes south of the 118 are mostly on flat, rectangular lots with straightforward access for equipment and materials. Once you get north of the freeway toward the Santa Susana Pass, lots get wider, slopes show up, and retaining walls become part of the conversation. That matters for an ADU: a flat lot in a neighborhood like Lake Manor or west of Topanga Canyon Boulevard is a very different job than a hillside parcel off Santa Susana Pass Road, where grading, drainage, and a geotech report often come before the first permit application.
Construction here is older than people expect. A large share of Chatsworth housing stock dates back to the 1960s and 1970s, which means original panel boxes, cast-iron drain lines, and roof framing that rarely matches today’s shear-wall requirements. Any addition that ties into the existing structure usually triggers electrical and plumbing upgrades, and we budget for that from the first conversation instead of discovering it mid-project. The soil is a known factor too: expansive clay means we often pour deeper footings than we would in other parts of the Valley, particularly for ADUs that carry a second story or a heavy prefab module.
Our Main Chatsworth Services
Most Chatsworth homeowners reach out for one of two things: a detached or attached ADU, or a ground-up addition that expands the main house. Here’s how each one works.
ADU Builders in Chatsworth
Building an ADU in Chatsworth usually means a detached unit in the rear third of the lot, between 400 and 1,000 square feet, often paired with a simple kitchen and a studio-style floor plan. The local permitting angle is forgiving: California state ADU law overrides a lot of local restrictions, which helps on older lots that were platted before today’s setback rules existed. We build both prefab and site-built ADUs, and the prefab route speeds things up considerably once foundations are in. Flat-lot access on streets like Lassen or Mason means crane placement and material staging are rarely a fight. For the full breakdown of cost and process, see our ADU Builders in Chatsworth page.
Home Addition Contractor in Chatsworth
A home addition in Chatsworth is usually a bedroom-and-bath wing, a second-story primary suite, or a family room extension that eats into the backyard. The structural reality here is that most existing homes need a foundation tie-in that meets current seismic standards, plus an electrical panel swap if the house still has its original 100-amp service. On flat lots, crews can usually dig and pour without shoring issues. On sloped lots north of the 118, expect more engineering, possible retaining walls, and a longer foundation phase. Our full process, including timeline and inspection milestones, is on the Home Addition Contractor in Chatsworth page.
Room Addition Contractor in Chatsworth
Room additions are the smaller sibling: a single office, a mudroom, a hobby studio, or a guest bedroom that doesn’t need plumbing. Because the scope is tight, these jobs are often the most cost-effective way to add real square footage without disrupting the whole house. In Chatsworth, the main considerations are roof-tie complexity and whether the addition crosses any side-yard setback lines on older parcels. A single room addition typically runs a much shorter construction schedule than a full wing, and we quote the entire job with a written price before any work begins. Details are on the Room Addition Contractor in Chatsworth 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 Chatsworth
We’re authorized to build with Abodu, Cover, and Dvele prefab systems, and we often spec James Hardie siding for additions and ADUs where the design calls for a low-maintenance exterior. Panels and components are drop-shipped to the Chatsworth job site with a lead time we confirm before you commit. See our brands for a full rundown on each option.
Pricing for ADU Company in Chatsworth, CA
These are planning figures for Chatsworth projects, reflecting the scope of work and local conditions. No surprises at the door: every Benson ADU Builders project starts with a written price before any work begins.
| Service | Typical range in Chatsworth |
|---|---|
| Prefab ADU (studio, 400 – 600 sq ft) | $150,000 – $225,000 |
| Prefab ADU (1-bedroom, 600 – 800 sq ft) | $225,000 – $315,000 |
| Prefab ADU (2-bedroom, 800 – 1,000 sq ft) | $315,000 – $410,000 |
| Site-built ADU (studio, 400 – 600 sq ft) | $175,000 – $260,000 |
| Site-built ADU (1-bedroom, 600 – 800 sq ft) | $260,000 – $360,000 |
| Site-built ADU (2-bedroom, 800 – 1,000 sq ft) | $360,000 – $460,000 |
| Garage conversion ADU (400 – 600 sq ft) | $90,000 – $160,000 |
| Home addition (bedroom + bath, 300 – 500 sq ft) | $120,000 – $200,000 |
| Home addition (family room, 300 – 500 sq ft) | $100,000 – $175,000 |
| Room addition (single room, 150 – 300 sq ft) | $55,000 – $110,000 |
What pushes Chatsworth prices upward is almost always site work: slope correction, retaining walls, soil reports, and upgraded foundations on clay-heavy ground. Homes with original electrical panels and cast-iron plumbing also carry higher tie-in costs than newer builds. Whatever the final scope, the written price you approve is the price we build to.
Neighborhoods We Serve in Chatsworth
We work across the entire Chatsworth area, from flatland neighborhoods south of the 118 to hillside parcels off Santa Susana Pass Road. Scheduling depends more on current crew availability in your area than distance, and most Chatsworth projects begin site visits within a few business days of the first call.
- Lake Manor
- Chatsworth Lake
- Rancho Susana
- Northeast Chatsworth
- West of Topanga Canyon Boulevard
Service Area – Cities Near Chatsworth
Beyond Chatsworth, our crews regularly cover surrounding San Fernando Valley communities. We serve Porter Ranch, CA to the north, Northridge, CA to the east, and Canoga Park, CA along with Reseda, CA farther into the Valley. If you’re on the edge of the service area, call and we’ll confirm coverage on your street.
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
Once you approve a written price and we file for permits, site visits and preliminary grading typically begin within a few weeks. Prefab ADUs often move faster than site-built because modules arrive pre-constructed. Call (903) 568-7222 for a current schedule based on your exact project.
ADUs in Chatsworth follow California state ADU law, which limits what cities and HOAs can restrict. You still need city building permits, and some HOA-governed neighborhoods require design review, but state law generally prevents HOAs from banning ADUs outright. We handle the permit package as part of every project.
Yes, and it’s the biggest local variable. Flat-lot builds on Chatsworth’s southern side usually need standard footings, while hillside lots can require geotech reports, retaining walls, and deeper concrete work. We factor all of that into the written price before you sign anything. Call (903) 568-7222 to get an exact quote for your lot, free.
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
"Booked a consult online and met the project manager two days later. Weekly progress updates arrived by text with photos. ADU finished on schedule."
- Hannah W."Clean, quiet crew. They respected the neighbors, kept noise to working hours, and swept the driveway every evening."
- Hope C."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N.
