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Cambria Home Additions & ADU: The Austin Owner’s Guide
We handle Cambria-forward home additions and ADU construction across Austin, with full-project pricing that typically runs $45,000 – $130,000 for additions and $90,000 – $220,000 for a permitted ADU, depending on square footage, foundation type, and how much Cambria surface area you’re planning to install. Most Austin homeowners call us because an existing addition is showing stress at the seam where new framing meets old, or because they bought a Cambria slab for a kitchen island and realized the base cabinetry underneath was never built to carry that much weight. Here’s what you actually need to know before you spend another dollar on a patch that won’t hold.
Key takeaways:
- Cambria surfaces are not the weak point in most failed Austin additions. The structure under them is.
- A home addition priced under $45,000 in Austin is usually a red flag: someone is leaving out permits, engineering, or both.
- We write the price before we pull a single permit, and the number on day one is the number on the final invoice.
- Every project carries a 365-Day Done Right Promise in writing, plus Cambria’s own lifetime warranty on the surface itself.
Which Cambria Models This Applies To
Cambria doesn’t make “addition-specific” slabs, which is exactly where Austin homeowners get into trouble. Every Cambria design works in an addition or ADU. The issue is slab thickness and overhang limits, not the color series. Cambria sells slabs in 2 cm and 3 cm thicknesses. For a kitchen island in a new ADU, we almost always order 3 cm, because a 2 cm slab needs a continuous substrate (the support layer underneath) and edge lamination to hold its line. In Austin’s humidity swings, a 2 cm slab on the wrong base will telegraph cracks at the seam within two years, especially in unconditioned ADU spaces where temperature swings daily.
Penhallow Remodeling Austin is an independent contractor. We’re not a Cambria dealer or affiliate, but we order directly from Cambria’s distribution network and install to their spec so the lifetime warranty stays intact. If you’re matching an existing Cambria edge profile in an addition, measure the overhang before you call anyone: Cambria’s standard unsupported overhang is 14 inches for 3 cm. Beyond that, you need corbels, brackets, or steel reinforcement. We’ve pulled slabs off cabinets in South Austin where someone skipped that step and the whole run had dropped a quarter inch at the outer edge.
Styles & brands we work with
Signs Your Cambria Home Addition or ADU Is Failing
- Hairline cracks at inside corners of windows in the new addition. This means the foundation connection between old structure and new is settling unevenly. The countertops and tile are usually the last thing to show it, but they will.
- Cambria slab pulling away from the backsplash or drywall seam. Movement, not adhesive failure. The addition’s floor framing or the cabinet base is shifting with Austin’s seasonal soil expansion. The black clay out here swells when wet and shrinks when dry, and additions bolted to older slabs feel every cycle.
- Gaps between the addition’s exterior and the original house where caulk keeps splitting. The seam is supposed to be a control joint. If it’s opening beyond 3/8 inch, the addition wasn’t tied to the main structure the way Austin code requires, or the piers weren’t set deep enough.
- Doors inside the addition that stick in summer and close fine in winter. Humidity movement, yes, but also a sign the addition’s roof load isn’t transferring the way the engineer drew it. This will show up in cracked Cambria seams eventually.
- ADU floor feels springy underfoot around the Cambria island or peninsula. Floor joist spacing or span was undersized for point loads. A Cambria island can weigh 600 to 900 pounds, and on 2×8 joists at 24 on center in an ADU, that weight is right at the limit before deflection starts cracking tile and grout around it.
Replacement Cost & What’s Included
In Austin, a full home addition with Cambria kitchen surfaces, new cabinetry, flooring, and all permitting runs $45,000 – $130,000. A detached ADU with Cambria in the kitchenette and bath runs $90,000 – $220,000. What moves the number: square footage ($180 – $320 per square foot for additions in Austin right now), site access (tight lots on the east side or in Travis Heights cost more for concrete and material handling), foundation type (pier and beam versus slab), and how much Cambria you’re running. One ten-foot island with a waterfall edge in Cambria can push $6,000 with fabrication, and that’s before the cabinets under it.
What’s included when we quote it: engineering stamps, city of Austin permits, demo and haul-off, framing, electrical, plumbing rough-in, drywall, paint, flooring, cabinet set, Cambria fabrication and install, and a written 365-Day Done Right Promise on the labor. If something fails because of our work inside that year, we come back and fix it at no charge, no service call, no re-inspection fee. That’s in writing, every job.
See the difference
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AfterDIY or Call Us?
If you’re just trying to figure out whether your existing addition or ADU is structurally sound before you spend anything, there are two things you can safely check yourself. First, look at the caulk line where the addition meets the house: if it’s split clean down the middle and the gap is wider than a nickel, that’s settlement. Second, step on the floor in front of your Cambria island and watch for movement in the seam where slab meets cabinet. No movement, no creak, no problem. Anything beyond that, and honestly even that, you should call us.
This is not a caulk-and-paint situation. Foundation movement under an addition or ADU in Austin carries real risk: a roof tie-in that fails during a storm, a gas line that shifts, an electrical panel that pulls away from a settling wall. Home additions are permitted, engineered work for good reason. If you’ve got movement, call us at (325) 225-5429 and we’ll tell you what we’re looking at before we ever send a crew.
FAQs
Cambria quartz carries a lifetime warranty against manufacturing defects, and in practical terms the surface will outlast the structure around it. The limiting factor in Austin is the addition itself: if the foundation is stable, the Cambria will look the same in 20 years as it did on install day. If the addition moves, no surface survives. That’s why we’d rather fix the structure first and set the slab last.
Yes, when the issue is a single point of failure, like undersized floor joists under a heavy Cambria island or a rotted rim joist at the exterior seam. We shore it up, sister in the correct lumber, and level the cabinets before reinstalling the slab. When the foundation itself is moving badly, a repair is just rent. You’ll need helical piers or deeper footings, and that’s a bigger number. We’ll tell you straight which one you’re looking at. Call (325) 225-5429 and we’ll walk the site and give you a written answer.
Most additions run 8 to 14 weeks from demo to final trim. ADUs run 12 to 20 weeks depending on utility runs and site grading. Cambria fabrication, once the cabinets are set, is templated digitally and installed within two weeks. Permitting with the city of Austin is the variable we can’t always shorten, and anyone who quotes you a faster number is probably skipping a step.
No, and no honest contractor does. Cambria is made to order in Minnesota and shipped to fabricators, so there’s always a two to three week lead on fabrication after templating. What we do keep on hand is the structural material behind the slab: cabinet bases rated for stone, steel overhang brackets, and substrate systems that meet Cambria’s install spec. The surface is the easy part. The load path under it is the work.
Get a Written Price Before You Decide
If your addition or ADU is showing cracks, movement, or just wasn’t built right the first time, call us at (325) 225-5429. Trevor’s line is the same one you’ll hear a real person answer, day or night. Tell us what you need, we’ll tell you what it costs, and we’ll go from there. The estimate is free, it’s written, and it’s the number we stand behind until the job is done and the guarantee takes over. KraftMaid, Silestone, and Kohler products are part of our regular material list too, so if the fix involves more than Cambria, we’ve got that covered as well.
Written by Trevor Nash, Owner, Penhallow Remodeling Austin at Penhallow Remodeling Austin, serving Austin and nearby areas.
