A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in San Marino, CA
An ADU in San Marino typically costs between $180,000 and $420,000 when built on one of the city’s large estate lots, and the process usually takes 9 to 14 months from design approval to final inspection. We’re Benson ADU Pasadena, and we handle ADU construction, home additions, and room additions across San Marino with a written price before any work starts. This page is your city overview: what makes San Marino jobs different, what things cost here, and how to reach us at (626) 658-3527 when you’re ready for a real number.
Why San Marino Homes Are Different
San Marino is not a typical tract-home city. The housing stock runs large and stately, mostly built between the 1920s and 1950s in Mediterranean, Spanish Colonial, and English Tudor revival styles. Most lots are oversized, and many properties still have detached garages set well back from the street. That changes how an ADU gets designed and built here. In San Marino, ADU work centers on matching the grandeur of the city’s large, architecturally significant estates while meeting stringent local design review and setback rules that demand ADUs be invisible from the street.
The climate helps. Warm, dry summers and mild winters mean construction can proceed year-round without weather shutdowns. But the heat matters for design. An ADU here needs real insulation and cooling capacity, not a window unit as an afterthought. We also see homeowners asking for shaded outdoor areas attached to the unit, which fits both the climate and the way San Marino properties are landscaped. Mature trees and hedges are common, and they often become part of the plan, hiding the ADU from view and preserving the estate feel. Design review in San Marino is strict, and matching roof tiles and exterior finishes is often the difference between approval and a redesign.
Our Main San Marino Services
San Marino homeowners call us most often for two things: a new ADU on the property or a home addition that respects the original architecture. Both start with the same Benson process: a written price, a clear scope, and no surprises at the door. Here’s what each involves here.
ADU Builders in San Marino
An ADU in San Marino is usually a detached unit tucked behind the existing garage or screened by mature landscaping, built to match the main house’s roof line and exterior finishes. The estate setback and design review rules are strict, so the unit often ends up being a carefully designed secondary structure rather than a visible addition. We build with prefab brands like Abodu, Cover, and Dvele when speed and precision matter, and we do site-built work when the design review board wants a closer architectural match. Every project gets a written price before work begins. ADU Builders in San Marino
Home Addition Contractor in San Marino
Home additions in San Marino mean extending a Spanish Colonial or English Tudor without making the addition look like an afterthought. The job often involves matching roof tiles, stucco texture, window styles, and even the way the original structure meets the ground. Because many homes are from the 1920s to 1950s, we plan for surprises inside the walls: older framing, outdated electrical, and foundation work that adds cost and time. We handle the full scope, from design coordination to permit-ready drawings to final inspection, with real-time tracking on every phase. Home Addition Contractor in San Marino
Room Addition Contractor in San Marino
A room addition in San Marino is often a single-purpose space: a home office, a guest suite, a gym, or a ground-floor bedroom for an aging parent. These projects run smaller than full additions but still face the same design review expectations. On a Tudor, that means the addition has to read as part of the original massing, not a box bolted onto the back. We price these as fixed-scope projects with a written quote, and we use James Hardie cladding or matching stucco depending on the house. Room Addition Contractor in San Marino
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 San Marino
We’re authorized to build with Abodu, Cover, and Dvele prefab systems, and we source James Hardie cladding for additions that need a durable, low-maintenance exterior. That means San Marino homeowners get curated options instead of a single take-it-or-leave-it product. See our brands for a full look at what we stock and install.
Pricing for ADU Company in San Marino, CA
| Service | Typical range in San Marino |
|---|---|
| Detached ADU (1-bed, prefab) | $180,000 – $260,000 |
| Detached ADU (2-bed, site-built) | $280,000 – $420,000 |
| Garage conversion ADU | $150,000 – $240,000 |
| Above-garage ADU | $220,000 – $350,000 |
| JADU (junior ADU, attached) | $90,000 – $150,000 |
| Full home addition (400 – 600 sq ft) | $180,000 – $320,000 |
| Primary suite addition | $140,000 – $240,000 |
| Room addition (single room) | $70,000 – $140,000 |
What pushes price up in San Marino is usually design review: matching roof tiles, custom stucco work, and architectural detailing on a Tudor or Spanish Colonial cost more than a standard finish. A steep or complicated lot can also add grading and drainage scope. Whatever the number lands at, you’ll see it in writing before any work starts, and that price does not change at the door.
Neighborhoods We Serve in San Marino
We work across San Marino, including the estate neighborhoods that make this city what it is. If you’re within the city limits, we’re already covering your street.
- The estates around Lacy Park
- Homes near Huntington Drive
- Neighborhoods south of the Huntington Library
- Streets off Orlando Road
- Properties near Valentine School
Response time for a San Marino estimate is typically within a few business days, and scheduling is coordinated from our Los Angeles office with crews serving San Marino locally.
Service Area – Cities Near San Marino
We also work in the cities around San Marino. If you’re just across the border, the same written-price process applies. Our nearby service area includes San Gabriel, CA, Pasadena, CA, South Pasadena, CA, and Monterey Park, CA.
Serving San Marino, CA - Our Local Coverage Area
We’re based in the San Marino 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 San Marino
We schedule San Marino estimates within a few business days of your call. The estimate includes a written price broken into line items, not a verbal range that shifts later. Call (626) 658-3527 and a live person answers, day or night.
Yes. San Marino has strict design review and setback rules, and most ADUs must be invisible from the street. We handle the design coordination and permit-ready drawings as part of the job, and we quote the process out in writing before you commit.
No. Every project gets a written price before work begins, and we hold to that number unless you change the scope. If a covered repair fails within 365 days, the Done Right Promise means we return and fix it.
Ready to see what an ADU or addition looks like on your San Marino property? Call Benson ADU Pasadena at (626) 658-3527 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 San Marino Customers Say
"Room addition off the kitchen. Framing, drywall, and paint all done well."
- Wade L."Fixed quote and clear change orders approved by text."
- Trina M."Photos of each milestone, which I loved. Slab, framing, roof dry-in, each one came with a few pictures by text."
- Gwen D.
