A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across San Marino
A home addition in San Marino typically runs $180,000 to $450,000 for a second-story addition, and $120,000 to $280,000 for a garage addition, depending on square footage, custom millwork, and how much design review coordination your property requires. Most San Marino additions take 6 to 12 months from permit to final inspection, and the variables that actually move the calendar are lead times on custom materials, not labor. We’re Benson ADU Pasadena, and we build additions throughout San Marino, from the Huntington Drive corridor to the quiet estate streets south of Lorain Road. Call (626) 658-3527 for a written price before any work begins.
Why Benson ADU Pasadena Is San Marino’s Preferred Home Addition Contractor
San Marino is a different animal than Pasadena or South Pasadena. The city’s design review board holds every exterior change to a standard most contractors only encounter on historic landmark registrations. We know that going in, so our proposals include the right roof tile match, the right window proportions, and the right setback strategy before you ever pay a deposit.
Homeowners here have told us the same thing for years: what they want most is a contractor who will manage the architect, the designer, the city, and the material vendors without making them chase anyone. That’s the job. Troy Eastman runs our crew planning and site supervision, and he’s built a process where you get real-time tracking on your addition, photo updates at every milestone, and a digital invoice you can pay from your phone. No surprises at the door.
Every project we take on in San Marino carries a written price before work starts, a 365-Day Done Right Promise, and a written guarantee stamped on the project file. If something isn’t right within a year, we make it right. That’s not marketing language. It’s the contract.
Second Story Addition Contractor in San Marino
A second story addition in San Marino runs $180,000 to $450,000 and typically takes 8 to 14 months, because city review, structural engineering, and material procurement all move on their own timelines. A Home Addition Contractor who hasn’t worked inside San Marino’s design restrictions will quote you fast and then stall when the board asks for revised elevation drawings. We plan for that review from day one.
Adding a second story above a detached garage is common here, especially on oversized lots where the existing footprint can’t expand outward without eating into mature landscaping. Foundations built for a 1940s two-car garage almost always need structural upgrading before they’ll carry a second floor, so we bring in a structural engineer early and include that cost in your written price.
Design review coordination
San Marino requires ADUs and additions to be invisible from the street where possible, which means your second story may need to sit behind the existing roofline or use matching clay or composite roof tiles to blend in. We handle the submittal package, respond to city comments, and schedule the review hearings so you don’t have to.
Long-lead material ordering
Custom millwork, leaded glass, and specialty siding often run 14 to 20 weeks lead time in today’s supply chain. We order those items before we break ground and lock your price in writing at that point, so you never see a mid-project change order because a vendor raised prices.
Garage Addition Contractors in San Marino
Garage additions in San Marino run $120,000 to $280,000, with most projects falling in the $160,000 to $220,000 range once you factor in design review, custom exterior finishes, and foundation work. Garage Addition Contractors who don’t know San Marino will propose a visible structure with off-the-shelf siding and hit a wall at permit review. We don’t.
Most San Marino homes built between the 1920s and 1950s have detached garages set well back from the street, which makes them ideal candidates for conversion into an ADU, a workshop, or extended living space. The challenge isn’t the structure. It’s making the new addition look like it grew there.
Tucked-behind-garage placement
San Marino’s design review strongly favors ADUs and additions tucked behind existing detached garages or screened by mature landscaping. On a recent project near Lacy Park, we placed a home office above the garage, completely hidden from the street by a mature magnolia. The city approved it on the first submittal because the elevation drawings showed zero visual impact from the curb.
Matching the estate’s roofline
Clay tile, slate-look composite, and Spanish Colonial profiles all show up on San Marino homes. Your addition needs to match, not approximate. We source matching materials through our approved vendor network, including James Hardie cladding and specialty millwork, and we confirm availability before we write your final price.
Trusted Brands We Service in San Marino
We build with and source from brands homeowners can research on their own: Dvele, Cover, Boxabl, and Mighty Buildings, plus James Hardie cladding and materials. For San Marino clients, that means you’re not stuck with whatever generic materials the contractor’s usual lumberyard happens to stock. You get curated options, with lead times and costs spelled out before you commit. On a recent second-story addition near Lacy Park, our crew coordinated with the homeowner’s architect to add a second-story addition above a detached garage, using custom English oak millwork and matching clay roof tiles. We ordered the James Hardie siding and specialty leaded glass from our approved vendors before breaking ground, locking the price in writing so the six-month lead time didn’t inflate the final cost.
Common Home Addition Contractor Problems We See in San Marino Homes
- Design review denial for visible ADUs. Contractors unfamiliar with San Marino propose additions with standard asphalt shingles or builder-grade siding, and the design review board rejects them. Your addition needs matching roof tiles and finishes that read as original to the estate.
- Blown schedules from custom millwork lead times. Custom English oak millwork, leaded glass, and specialty cabinetry routinely run 16 to 20 weeks lead time. Contractors who wait until framing starts to order them end up pushing completion dates by months. We order before ground breaks.
- Clashing architectural styles. San Marino has a concentration of Spanish Colonial, Tudor revival, and Mediterranean homes. A contractor who doesn’t coordinate with your architect or designer can easily spec finishes that fight the home’s original style instead of extending it.
- No heat mitigation in the design. San Marino’s Mediterranean climate means warm, dry summers, and a poorly insulated second story becomes unusable by August. We size HVAC, insulation, and window placement for heat waves, not just the average summer day.
Pricing for Home Addition Contractor in San Marino, CA
Here’s what we tell San Marino homeowners before any site visit: a second-story addition runs $180,000 to $450,000. A garage-based ADU or addition runs $120,000 to $280,000. A bump-out addition for a kitchen or bath runs $80,000 to $180,000. What moves the number is square footage, foundation work, custom millwork scope, and how much of the existing roofline has to be matched. San Marino design review adds planning time, not inflated labor. You get a written line-item price before any work starts, and that price doesn’t change unless you change the scope. Call (626) 658-3527 for your exact quote. Estimates are free.
We Also Serve Cities Near San Marino
Our crews handle home additions throughout San Marino and the surrounding cities, including San Gabriel, Pasadena, South Pasadena, and Monterey Park. If your property sits near the San Gabriel border or just south in San Gabriel proper, we can still help. Dispatch and scheduling are coordinated from the brand’s Los Angeles office, and crews serve San Marino locally every week. Call (626) 658-3527 for a written quote.
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 Home Addition Contractor in San Marino
San Marino requires additions to match the existing home’s roof tiles, window proportions, and exterior finishes closely enough to pass design review, and the city is stricter about this than neighboring Pasadena. You’ll need matching clay or composite roof tiles and exterior finishes that read as original to the property. We handle the design review submittal and respond to city comments so your permit doesn’t stall. Call (626) 658-3527 and we’ll walk through your specific elevation requirements.
Custom millwork, leaded glass, and specialty cabinetry typically run 14 to 20 weeks lead time from order to delivery, and that schedule runs independently of framing and drywall. We order all long-lead items before we break ground and lock your price in writing at that point, so vendor price increases never show up as change orders. Call (626) 658-3527 for a written schedule and price before you commit.
Yes, and it’s one of the most common additions we build in San Marino because the garage is already set back from the street, which makes it easier to satisfy the city’s requirement that ADUs be invisible from the curb. You’ll need a structural engineer to verify the foundation can carry a second floor, and we include that cost in your written quote. Call (626) 658-3527 to schedule a site walk.
We coordinate directly with your architect or designer from the first meeting, matching roof tile profiles, window proportions, and exterior finishes to your home’s revival style instead of forcing a generic modern box onto a Tudor or Spanish Colonial estate. On a recent Tudor near Lacy Park, we matched custom English oak millwork and clay roof tiles so the addition reads as original to the home. Call (626) 658-3527 to talk through your home’s specific style.
Yes, every addition we build in San Marino is designed for the city’s hot, dry summer stretches, with insulation and HVAC sizing that work when temperatures climb into the high 90s, not just on an average summer afternoon. We also plan shaded outdoor areas and window placement to reduce afternoon heat gain. Call (626) 658-3527 for a written plan that covers comfort as well as design review.
Written by Troy Eastman, Owner at Benson ADU Pasadena, serving San Marino home additions with written pricing and the 365-Day Done Right Promise.
