







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Perris, CA
Adding an ADU in Perris usually costs between $180,000 and $320,000 for a site-built one-bedroom unit, with prefab options from brands like Abodu and Cover starting around $160,000. That’s the honest ballpark before you tap call. Perris is different from most Inland Empire cities because of its mix of half-acre ranch lots and tight 2000s tract yards, plus older septic systems that can quietly derail a backyard project. We’re Benson ADU Builders, led by Troy Eastman, and we put every price in writing before work starts. Call (831) 231-0809 to talk through your lot.
Why Perris Homes Are Different

Perris wasn’t built all at once. The housing stock jumps from 1950s and 60s ranch homes on oversized lots to 1990s and 2000s stucco subdivisions with compact, uniform yards. That split changes everything about how an ADU gets designed and permitted. An older half-acre lot near the Perris Valley Channel might have an abandoned septic tank or leach lines that failed a perc test decades ago, and the city will want that resolved before a detached unit gets approved. A newer tract home off Nuevo Road usually has a small side yard, which pushes the design toward a JADU, a junior ADU carved from existing square footage inside the house, rather than a standalone structure.
The climate adds its own layer. Perris summers run hot and dry, with Santa Ana winds kicking dust across the flats, and some winters bring enough rain to test drainage in the lower-lying streets. That means an ADU here needs high-reflectance roofing, extra ceiling insulation, properly sized HVAC, and tight air sealing. It also means we check the grade and drainage pattern before we ever draw a foundation. None of this is generic California ADU content. It’s what we see on Perris lots every week.
Our Main Perris Services
Most Perris homeowners call us about one of three projects: building a new ADU from the ground up, adding square footage to the main house, or converting an existing room or garage into usable living space. Each has its own dedicated Perris page with specifics.
ADU Builders in Perris
Backyard homes are the big one in Perris right now, partly because the city is actively pushing for more affordable rental units and partly because so many older lots have the room. We handle detached ADUs, garage conversions, and JADUs. On pre-1980 lots we check for abandoned septic tanks early, because a buried tank nobody knew about can push a permit back by months. We build both site-built and prefab units, including Abodu, Cover, and Dvele models, so you’re not locked into one manufacturer. Full details are on the ADU Builders in Perris page.

Home Addition Contractor in Perris
Some Perris homes should grow instead of getting a separate unit. A home addition works when a family needs a larger kitchen, a second living area, or an extra bedroom attached to the main house. On the older ranch lots, additions often tie into existing slab foundations and need careful insulation and roof tying to handle the summer heat. On newer stucco homes, the work is usually about matching the exterior so the addition doesn’t look bolted on. See the Home Addition Contractor in Perris page for scopes, timelines, and pricing.

Room Addition Contractor in Perris
A room addition is the smaller cousin: one room, not a wing. Perris homeowners use these for a home office, a nursery, a den, or a fourth bedroom. In the older ranch neighborhoods, a single-room addition often costs less than reworking the entire floor plan, and it can be permitted faster than a full ADU because the setbacks and utility requirements are lighter. The Room Addition Contractor in Perris page breaks down what a single room costs to add here and what the typical timeline looks like.

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 Perris
We build with and service prefab ADUs and materials from James Hardie, Abodu, Cover, and Dvele. Parts and panels for these systems are stocked regionally, so a Perris project isn’t waiting on a container from out of state. More detail is on our brands page.
Pricing for ADU Company in Perris, CA
| Service | Typical range in Perris |
|---|---|
| Detached ADU (site-built, 1 bed) | $180,000 – $320,000 |
| Detached ADU (prefab, 1 bed) | $160,000 – $250,000 |
| Garage conversion ADU | $90,000 – $150,000 |
| JADU (junior ADU inside existing home) | $60,000 – $110,000 |
| Home addition (kitchen or family room bump-out) | $120,000 – $220,000 |
| Full master suite addition | $150,000 – $280,000 |
| Single room addition (office, bedroom, den) | $60,000 – $140,000 |
| Site work / septic abandonment / utility tie-ins | $8,000 – $30,000 |
What pushes a Perris price up is usually septic abandonment on the old ranch lots, grading fixes on low-lying parcels, or extra insulation and a bigger HVAC unit for the summer. What doesn’t push it up is a contractor changing the number after work starts. Our price is written before we begin, and the 365-Day Done Right Promise stays behind it.
Neighborhoods We Serve in Perris

We run crews across the whole Perris valley, from the older ranch streets west of the 215 to the newer subdivisions east of the lake. The lot type matters more than the neighborhood name, but here are a few areas we’re in regularly.
- North Perris, near the Perris Valley Channel
- Historic downtown Perris and the surrounding grid
- The ranch-lot streets south of Nuevo Road
- Newer subdivisions east of Lake Perris
- Streets around Perris High School and the fairgrounds
Most of these areas are within a short drive of our Inland Empire scheduling office, so estimates and site visits don’t involve a long wait.
Service Area – Cities Near Perris
Benson ADU Builders also serves homeowners in Moreno Valley, CA, Riverside, CA, Grand Terrace, CA, and Loma Linda, CA. If you’re just over the city line, call us. The written-price promise and the 365-day guarantee follow the same way.
Serving Perris, CA - Our Local Coverage Area
We’re based in the Perris 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 Perris

Most Perris homeowners get an estimate visit within a few business days of calling. Scheduling runs through our Inland Empire office, and crews are dispatched locally, so we aren’t driving in from outside the region. Call (831) 231-0809 and a live person picks up.
Some of the newer Perris subdivisions have HOAs with design-review rules, and the city checks for old septic systems on pre-1980 lots. Neither has to stop the project. We flag both issues in the written estimate so there are no surprises later. Call (831) 231-0809 for a free look at your lot.
No. The price we put in writing before work starts is the price you pay, unless you add scope yourself. That’s the Relay Visibility Guarantee, and the 365-Day Done Right Promise sits behind it. Call (831) 231-0809 to schedule your free estimate.
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 Perris 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."Communication was the best part. I always knew what was happening that week without having to ask."
- Dolly N."Garage conversion into a guest suite. I could see the permit status in the app, which made it painless."
- Rick F.




