Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Cambria Home Additions & ADU: The San Jose Owner’s Guide
Cambria home additions and ADU construction in San Jose typically runs $53,100 to $153,400 depending on square footage, site prep, and finish level. Bradford Remodeling Co San Jose performs full-scope additions and accessory dwelling units with a written price before any work starts, and we install Cambria surfaces as part of the finish package when the design calls for it. Most San Jose homeowners reach out after realizing their existing space simply won’t carry the load anymore, whether that’s a growing family, aging parents moving in, or a rental unit that needs to start paying for itself.
Here’s the straight read on how this works, what it costs, and where Cambria fits into the picture.
Which Cambria Models This Applies To
Cambria is a quartz surface line, not a structural component, so the brand comes into play at the finish stage of a home addition or ADU: countertops, bath vanities, shower surrounds, and backsplash applications. Every Cambria slab we specify runs roughly 3 centimeters thick (about 1.25 inches), which is standard for countertop spans without extra substrate support. The product line spans dozens of design series, from the darker tones in the Brittanica line to the veined patterns in the Marble and Coastal collections.
Here’s the compatibility gotcha most San Jose owners don’t see coming: Cambria slabs are non-porous quartz and heavier than natural stone per square foot. That weight matters on kitchen islands and peninsula overhangs in additions, where the framing plan has to account for dead load before the countertop crew even measures. A 10-foot island run can add several hundred pounds to the floor system, which is exactly why we coordinate the structural drawings with the finish schedule early, not after drywall goes up.
One more spec to know: Cambria’s warranty is tied to authorized fabrication and installation, so if you’re matching a slab in an existing kitchen with new counters in an ADU, the dye-lot consistency between batches is tight but not exact. We order slabs from the same series and inspect the visual match before fabrication starts. Bradford Remodeling Co San Jose is an independent contractor, not affiliated with Cambria, but we work with their authorized fabricators so every slab carries the manufacturer’s written warranty.
Styles & brands we work with
Signs Your Cambria Home Additions & ADU Is Failing
- Seam separation at countertop joints. Quartz seams rely on epoxy, and when an addition settles or shifts slightly, a hairline gap opens at the seam line. This is almost always structural movement underneath, not an adhesive failure. In San Jose’s clay-heavy soils around Willow Glen and the east foothills, seasonal expansion and contraction makes this more common than people expect.
- Chipping along the edge profile. Cambria is tough but brittle at a sharp edge. A dropped cast-iron pan or a ladder bumped during the addition’s finish work can take a chunk out of an eased or beveled edge. Small chips can sometimes be filled; larger breaks usually mean section replacement.
- Cracked slab at the sink cutout. The narrow front and back rails on either side of an undermount sink are stress points. If the cabinet underneath shifts, or if the installer overtightened the sink clips, a crack starts there and runs. We see this on older ADU kitchen counters where the cabinet boxes have sagged from moisture exposure.
- Visible flex when you press down on an overhang. A Cambria overhang longer than 12 inches without corbels or a steel support bracket will deflect slightly under hand pressure. If you can feel the countertop move, the support structure underneath wasn’t built to the span. That’s a framing correction, not a countertop repair.
- Dull spots that won’t polish out. Quartz doesn’t need sealing like granite, but aggressive cleaners, especially anything acidic or abrasive, can etch the resin binders over time. If a section of the counter looks flat or hazy next to the original finish, the surface has been compromised and needs professional restoration or replacement.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
The full picture on a San Jose home addition runs $53,100 to $153,400. That range covers design, structural engineering, permits, foundation work, framing, electrical and plumbing rough-in, insulation, drywall, flooring, finishes, and the Cambria surface package. At the lower end, you’re looking at a simple bump-out or single-room addition with modest finishes. At the upper end, a full ADU with a kitchen, bath, separate entrance, and utility connections.
| Scope | San Jose Installed Range |
|---|---|
| Home Addition (full scope) | $53,100 – $153,400 |
| ADU Construction (permitted, utilities connected) | $106,200 – $259,600 |
| Garage Conversion (existing structure) | $35,400 – $94,400 |
| Countertop Installation (Cambria, per project) | $2,360 – $7,670 |
| Kitchen Remodel (within addition/ADU) | $16,520 – $53,100 |
What drives the spread: site access for equipment, soil conditions that affect foundation depth, whether the existing electrical panel has capacity for an ADU subpanel, and how much trenching is required for sewer and water lines. We put every number in writing before a single tool comes out. That’s The Garrison Standard: a line-item price, signed, no numbers that move at the door. If the scope holds, the price holds.
All work is covered by our 365-Day Done Right Promise. If anything we installed fails within one year, Bradford Remodeling Co San Jose returns and corrects it at no charge. That includes the Cambria installation work we direct.
DIY or Call Us?
Cambria countertop installation is not a weekend project. The slabs weigh roughly 16 pounds per square foot, a single kitchen run can weigh several hundred pounds, and fabrication requires wet-cutting with diamond tooling. A wrong cut means a ruined slab, and slabs aren’t cheap. Your time and money are better spent on the parts of the project you can genuinely handle: clearing the work area, documenting your existing layout with measurements and photos, and getting your material selections dialed in before the crew shows up.
Where DIY really goes wrong on additions and ADUs is the structural and utility side. Concrete formwork, load-bearing wall removal, electrical panel work, and sewer connections require permits and inspections. Get any of it wrong and you’re looking at failed inspections, re-work costs, or worse. We’re not saying you can’t own the project. We’re saying the parts that can hurt you or your house deserve a professional. Call (669) 272-2637 and we’ll give you a straight number.
FAQs
Cambria quartz carries a lifetime limited warranty from the manufacturer when installed by an authorized fabricator, and we’ve seen installations from the early 2000s that still look right. What shortens the lifespan in San Jose specifically is structural settling underneath and harsh cleaning products on the surface. Keep the countertop supported properly and clean it with mild soap and water, and it will outlast the project it was installed in.
Yes, certain damage can be repaired: small chips can be filled with color-matched epoxy, and light scratches can be buffed to blend with the surrounding finish. Cracks that run through the full slab thickness, seam failures that keep reopening, and heat damage that causes discoloration typically require section or full replacement. The only way to know which category yours falls into is a visual inspection. Call (669) 272-2637 and we’ll look at it honestly.
A typical single-room addition in San Jose runs 3 to 5 months from permit approval to final inspection. A full ADU with kitchen and bath runs 5 to 9 months. The permitting phase alone can take 4 to 12 weeks depending on the city’s current backlog and whether your lot has any planning restrictions. We give you a written schedule at contract signing, and Curtis Lane walks the site personally at every major milestone.
We order Cambria slabs per project from authorized fabricators in the Bay Area, which means your slab arrives matched to your specific design and cut list. We stock common tools and hardware for installation work, but countertop slabs are job-specific. Lead time from slab selection to installation is typically 2 to 4 weeks.
Straight number, written scope, done when we said done. Call Bradford Remodeling Co San Jose at (669) 272-2637 to schedule your free estimate. We also work with KraftMaid cabinetry, Silestone surfaces, and Kohler fixtures on addition and ADU projects.
Written by Curtis Lane, Owner, Bradford Remodeling Co at Bradford Remodeling Co San Jose, serving San Jose and nearby areas.
