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Cambria Home Additions & ADU: The San Francisco Owner’s Guide
Most families don’t start with “home addition” in mind. They start with a Cambria countertop that’s suddenly in the wrong place because the kitchen doesn’t hold everyone anymore, or a bedroom that worked when the kids were little and now can’t fit a single overnight guest. And somewhere in that conversation is the real question: what would it actually cost, in San Francisco, with permits, with a contractor who writes the price down before anything gets torn out?
For a home addition tied to Cambria surfaces and cabinetry, expect to invest $53,100 – $153,400 depending on square footage, foundation work, and how much of the existing room needs to be rebuilt around the new Cambria slab. On ADU construction in San Francisco, the range runs $106,200 – $259,600, which includes the countertop, the cabinets, the plumbing, the electrical, and the paperwork. We’ll walk you through exactly what moves that number.
Which Cambria Models This Applies To
Cambria isn’t one product. It’s a family of quartz surfaces with different series, and each series has its own finish, thickness, and edge style. The good news is that home additions and ADUs don’t need you to match an exact Cambria design from ten years ago. Cambria still produces many of its classic series, and if your original design has been retired, there’s usually a current equivalent within a shade or two. When we’re planning an addition around an existing Cambria countertop, we measure the slab thickness (most Cambria tops run 2 cm or 3 cm), the edge profile, and the finish (Cambria’s matte and high-gloss finishes read differently under San Francisco’s coastal light, which matters if you’re adding on a kitchen wing that gets morning sun from the bay side).
One compatibility detail worth knowing: Cambria slabs are quarried in a single plant in Minnesota and are remarkably consistent from batch to batch, but color drift does happen across production years. If the addition calls for new Cambria adjacent to an older slab, we photograph the existing surface in daylight, send those photos to the Cambria distributor, and have the new slab moved so the veining direction lines up. That’s the kind of thing that shows up in the finished room and never in a quote from someone who doesn’t handle Cambria regularly.
We also stock and work with KraftMaid cabinets, Silestone and Kohler fixtures, so the addition coordinates with the rest of the house rather than looking like an afterthought.
Styles & brands we work with
Signs Your Cambria Home Additions & ADU Is Failing
An addition doesn’t fail like a furnace fails. It fails in small, specific ways that add up to a room that doesn’t work the way it should. Here’s what we see most often in San Francisco homes:
- The countertop seam opens up or the slab shifts. This usually traces back to the original install or the cabinet structure underneath. Cambria is dense, but if the sub-base was never leveled for the weight, the slab can settle. In older San Francisco homes with sloped floors (very common in the Sunset and Richmond districts), leveling matters even more.
- Doors start sticking or not closing cleanly. Additions move differently than original construction. If the foundation separates from the original house, doors are the first thing to tell you. This is a structural warning, not a cosmetic one.
- The room never holds its temperature. Fog-belt homes need proper insulation and vapor management. An addition that’s always cold or always damp usually means someone cut corners in the walls, not the windows themselves.
- Water pools near the base of exterior walls. Grading and drainage in San Francisco’s hills are unforgiving. If water sits against the addition after rain, the problem is drainage design, and it will find its way inside eventually.
- Permits were never pulled on the original addition. We see this in older San Francisco homes more than people expect. It shows up at resale, with an inspector, or when someone tries to add onto the addition. It’s fixable, but it changes the plan and the price.
See the difference
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After
Before
After
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AfterReplacement Cost & What’s Included
For San Francisco, a home addition linked to Cambria surfaces and cabinetry runs $53,100 – $153,400. An ADU runs $106,200 – $259,600. The range reflects square footage, foundation condition, plumbing and electrical scope, and whether you’re adding Cambria to just the kitchen or to additional surfaces like a laundry counter or an island.
What’s included in our written price: the permits pulled in your name, the Cambria slab (delivered and installed), the cabinets, the flooring transitions, the paint, the clean-up, and a photo of the finished job before the crew leaves. You get the written price before any demolition starts, and you get the 365-Day Done Right Promise when the project is finished. If it’s not done right, we make it right. There’s no separate charge for drop cloths or shoe covers on your stairs. There’s no charge for asking questions before anything is moved.
- Home Addition (typical scope): $53,100 – $153,400
- ADU Construction (permits, Cambria, cabinetry, finish work): $106,200 – $259,600
- Garage Conversion (Cambria + cabinetry where applicable): $35,400 – $94,400
DIY or Call Us?
You can check a few things yourself: whether water pools against the addition after rain, whether the Cambria seam is still tight, whether doors close cleanly. Those observations help us plan the first site visit. But the actual construction of an addition or an ADU in San Francisco is not a weekend project and not a series of videos away. Foundation work, shear wall requirements, plumbing vents, and slab handling all carry real risk. A Cambria slab for an island can weigh a few hundred pounds. A wrong lift with a few hundred pounds of quartz on an uneven floor can end with an injury and a broken slab that no one is replacing for free.
If you’re reading this because something already isn’t right with an existing addition, call us at (831) 480-4497. We’ll come look, tell you honestly whether it’s a small correction or a larger structural problem, and write it down before anything starts.
FAQs
A properly permitted and constructed addition should last as long as the original house, and that’s the truth for homes throughout San Francisco. The Cambria surface itself carries a manufacturer lifetime warranty, and the workmanship is covered by our 365-Day Done Right Promise. What shortens the lifespan of an addition here is not materials; it’s shortcuts. Undersized foundations and skipped drainage details show up within the first three rainy seasons. Call (831) 480-4497 if the work was done recently and you’re seeing signs of settling or water entry.
Often, yes. The answer depends on whether the foundation is still sound and whether the original work was permitted. We’ll tell you what can be salvaged and what can’t, and we’ll tell you before any work is scheduled. Call us at (831) 480-4497 and we’ll take a look.
A modest home addition in San Francisco typically runs three to five months depending on permitting and inspection schedules. An ADU can run four to eight months. That includes time for Cambria templating and slab delivery, which has to be scheduled after cabinetry is set. We set quiet hours during the day so children can nap and remote work can happen, and we keep you informed about what happens each week before it happens.
We order Cambria directly from the distributor for each job, by project. That means you’re never choosing from someone’s leftover slab, and the surface arrives matched to your measurements. We do stock and install other named brands on the same projects, including KraftMaid and Silestone, so the full room comes together from one crew and one plan.
No. The written price you receive before work starts is the price, unless you ask to change the scope. If you add a window or move a wall, we’ll reprice it in writing before that change is made. That’s the rule on every Elmstead Remodeling San Francisco project, and it’s the way I’ve written estimates for years. Tell me what the room needs to do, and we’ll figure out the rest from there.
If you’re weighing an addition or an ADU with Cambria surfaces in San Francisco, start with the free estimate. Call (831) 480-4497 and someone will pick up, answer your questions, and schedule the first visit. No voicemail tree, no waiting until Monday.
Written by Graham Stein, Owner, Elmstead Remodeling San Francisco at Elmstead Remodeling San Francisco, serving San Francisco and nearby areas.
