Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Cambria Home Additions & ADU: The San Francisco Owner’s Guide
Adding square footage to a San Francisco home with Cambria surfaces throughout typically runs $53,100 to $153,400 for a full addition, and $106,200 to $259,600 for a standalone ADU. We stock Cambria-compatible materials and install them on our own home addition and ADU projects across San Francisco, from the Richmond District down to the Excelsior. What usually brings a homeowner to this page: they’ve gotten a bid from another contractor, the numbers shifted once demo started, and now they want a written price for a Cambria-finished addition that won’t move at close-out.
We give you exactly that. Straight number, real scope, no surprises at close-out.
Which Cambria Models This Applies To
Cambria runs its product line in series rather than model numbers the way an appliance manufacturer would. The practical difference for a San Francisco addition or ADU is thickness and finish. Cambria slabs come in 1 cm, 2 cm, and 3 cm thicknesses, with 3 cm being the standard for kitchen islands, bathroom vanities, and wet bars in new construction. Design series like the Coastal, Marble, and Quartz collections all use the same structural specs, so compatibility is about profile and edge detail, not a specific line.
Where we see homeowners get tripped up: 2 cm Cambria with a laminated edge looks identical to 3 cm from across the room, but it needs a plywood substrate underneath and will not hold up as a freestanding island overhang. If you’re matching an existing Cambria counter to a new ADU kitchen, we measure the slab thickness and the edge profile before we quote. On the OEM-versus-aftermarket question, Cambria does not sell repair parts or touch-up kits through retail channels, so any “OEM” patch material sold online is not coming from Cambria. We use Cambria-sourced slabs for new work and manufacturer-approved fabrication methods for seams and cutouts.
Styles & brands we work with
What “Cambria Home Additions & ADU” Actually Covers
This page covers the full scope of work where Cambria material gets installed as part of a larger structural project. In San Francisco that means:
- Attached home additions – new bedrooms, expanded kitchens, family rooms built onto the existing structure. Cambria goes in at the countertops, island, and often a wet bar or laundry fold.
- Detached ADUs – backyard units with a full kitchen and bath, where Cambria typically lands on the kitchen counters, bathroom vanity, and sometimes a shower bench or window sill.
- Garage conversions – turning a San Francisco garage into living space, which brings its own set of code requirements for ceiling height, egress, and insulation before any finish surface goes in.
- Interior remodels that expand the footprint – bump-outs and dormer additions where Cambria ties into the existing kitchen or bath.
We also work with KraftMaid and Wellborn cabinetry, Silestone, and Kohler fixtures on these projects, so the Cambria surface lands on a documented, warrantied base rather than whatever the cabinet shop had in the yard.
Signs Your Home Addition or ADU Plan Is Heading Off the Rails
Most homeowners don’t discover a problem with their addition or ADU project until the wrong piece is already ordered or the wrong sub is already scheduled. Here’s what we see on San Francisco job sites:
- The written quote doesn’t itemize the Cambria slab cost. If the countertop line just says “Cambria” with no slab thickness, square footage, or edge profile, you don’t have a price. You have a placeholder. That’s how a $53,100 addition becomes a $62,000 invoice at cabinet install.
- Your contractor can’t tell you how the slab gets into the ADU. San Francisco backyards are tight. A 3 cm Cambria slab for a 10-foot island weighs over 400 pounds and doesn’t bend around the corner of a 1920s garage. If nobody has measured the access path, the slab is getting cut on site, and that changes the seam layout and the price.
- The ADU kitchen layout ignores the Cambria jumbo slab size. Cambria sells jumbo slabs roughly 132 inches by 65 inches. Design an island longer than that without accounting for a seam, and you’ve just added fabrication cost and a visible joint nobody wanted.
- The addition framing doesn’t account for the counter overhang. A 3 cm Cambria overhang longer than 12 inches needs steel or corbel support built into the cabinetry or framing before drywall goes up. Retrofitting support after the fact means cutting into finished walls.
- Nobody pulled the permit for the gas line to the ADU range. You can spec Cambria all day, but if the gas rough-in wasn’t inspected before the counters went in, the whole kitchen island has to come back out to expose the wall. That’s a real cost and a real delay, and we’ve seen it more than once in the Outer Sunset.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
In San Francisco, a full home addition with Cambria surfaces runs $53,100 to $153,400. A detached ADU with a Cambria-finished kitchen and bath runs $106,200 to $259,600. The spread comes from structural scope: a ground-floor bump-out on a concrete slab costs far less than a second-story addition over a balloon-framed 1910s house in the Richmond, where the existing framing has to be brought up to current shear requirements before any finish work starts.
Every Bradford Remodeling quote includes the Cambria slab cost by square footage and thickness, fabrication, edge profile, sink cutout, and install labor as separate line items. You’ll see the structural line, the rough-in line, and the finish line as separate numbers. No allowances, no “to be determined” columns. The written price you sign is the price you pay, and the 365-Day Done Right Promise covers the completed work in writing for a full year. If a seam separates or a cabinet pulls away inside that window, we return and correct it at no charge.
DIY or Call Us?
For a home addition or ADU, DIY means one of two things, and both go badly. First: you pull the permit as owner-builder and coordinate subs yourself. In San Francisco, that means managing DBI inspections, scheduling around the city’s plan-check backlog, and coordinating Cambria fabrication with a structural timeline you’re learning in real time. Most owner-builders land 30 percent over budget and six months late, and that’s before we talk about the finish details that make or break the final product.
Second: you attempt finish work like Cambria countertop install yourself. A 3 cm slab is not a drywall patch. Wrong lift technique, wrong support, or a bad seam and you’ve damaged a $4,000 to $8,000 slab that cannot be repaired. This is not a weekend project. Call us at (831) 610-5598 for a written quote and let our crew handle the structural, the rough-in, and the Cambria install under one scope and one guarantee.
FAQs
A typical attached addition runs 4 to 7 months from permit submittal to final inspection; a detached ADU runs 6 to 10 months depending on plan-check timing at DBI and site access. The Cambria slab itself is fabricated off-site and installs in one day once the cabinets set. Call (831) 610-5598 for a timeline tied to your specific scope and neighborhood.
Seam separation can be re-glued and re-polished. A cracked slab cannot be structurally repaired, and a chip near an edge can be filled but will always read in the light. For an addition or ADU, we spec the slab thickness and support correctly the first time so repair never becomes the conversation.
Cambria countertops on an ADU kitchen and bath typically land between $2,360 and $7,670 installed, depending on square footage, slab thickness, and edge profile. That number sits as its own line item on a Bradford quote, separate from framing, drywall, and rough-in. Call (831) 610-5598 and we’ll price your specific layout.
We order Cambria per project from Cambria’s fabrication partners, which means your slab is selected for your job and your measurements, not pulled from a warehouse remnant and made to fit. This also keeps your warranty chain clean: manufacturer specs, manufacturer fabrication standards, documented install.
No. The written price is fixed before demo, and The Garrison Standard requires every line item in writing before any tool hits the job. The only way a number changes is if you change the scope, and that gets documented as a written change order with its own price before any new work begins.
Written by Curtis Lane, Owner, Bradford Remodeling Co – San Francisco, CA at Bradford Remodeling Co San Francisco, serving San Francisco and nearby areas.
