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Cambria Home Additions & ADU: The Houston Owner’s Guide
Cambria home additions and ADU projects in Houston typically run $45,000 to $130,000 for the full build, with Cambria quartz countertops adding $2,000 to $6,500 per surface depending on slab selection and linear footage. Most Houston homeowners call us when they’ve outgrown their current footprint and want to stay in their neighborhood rather than move. You’re likely here because you’re weighing whether to expand, convert, or build a separate unit, and you want a real number before you get too far down the road.
Which Cambria Models This Applies To
Cambria quartz surfaces come in over 180 designs across a handful of finish families: standard polish, matte, and high-gloss. For home additions and ADUs, the compatibility question isn’t really about model numbers, it’s about slab size, thickness, and the edge profile your fabricator cuts. Cambria slabs run 55.5 inches by 122 inches, which matters when you’re planning an island in a converted garage or a long run of counter in an addition. The two thicknesses we spec most often are 2cm and 3cm. A 3cm slab can carry its own weight across a 24-inch cabinet span without extra plywood underlayment; 2cm usually needs a support layer, which affects your cabinet height and your final labor number. As an independent contractor, Penhallow Remodeling Houston isn’t affiliated with Cambria, but we install their product regularly. When a homeowner asks whether to use OEM Cambria slabs or a comparable quartz from Silestone or Caesarstone, we walk them through what we’ve seen hold up in Houston’s humidity and heat. For a kitchen island in a new addition, Cambria’s larger slab format means fewer seams, and fewer seams means fewer places for water to get in over time.
Styles & brands we work with







Signs Your Cambria Home Additions & ADU Is Failing
Most homeowners don’t realize something’s wrong with an addition or ADU until a small problem has already been costing them money. Here’s what we see on service calls around Houston:
- Hairline cracks around island overhangs. Cambria quartz is tough, but a 12-inch unsupported overhang with heavy daily use will eventually show stress. The fix is almost always adding steel support brackets or corbels before the crack spreads into the slab.
- Doors and windows binding or sticking. In Houston the clay-heavy soil around neighborhoods like Meyerland expands and contracts with moisture. If your addition wasn’t built on piers or with proper slab reinforcement, the structure shifts and the doors tell you first.
- Humidity pooling in corners or on the underside of the ceiling. Additions with underpowered HVAC returns or missing vapor barrier in the crawlspace turn into sweatboxes by August. You’ll see condensation before you see mold.
- Cold spots along the new wall’s baseboard. This usually means the insulation was skipped or compressed behind the drywall during a low-bid addition. Your AC runs harder and your floors never feel right.
- Grout or caulk separation at the Cambria backsplash seams. This is often the first visible sign of the structure settling unevenly. If you re-caulk and it splits again within a year, the slab is moving, not the caulk.
Any one of these is worth a look. Taken together, they usually mean the original build cut a corner somewhere.
See the difference
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After
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AfterReplacement Cost & What’s Included
For Houston homeowners, a full home addition starts around $45,000 for a modest bump-out and runs to $130,000 or more for a large room with plumbing, electrical, and a new roofline. An ADU is a bigger lift: $90,000 to $220,000 when you account for the separate foundation, utility connections, and the City of Houston permitting process. Cambria countertop work inside those projects adds $2,000 to $6,500 per surface, depending on linear footage, edge profile, and slab thickness. What drives the number up or down is usually the foundation work Houston soil demands, the distance from your existing plumbing stack, and the quality of insulation you choose. Every Penhallow Remodeling Houston estimate is a written price before any work starts. That price includes the Cambria material, fabrication, install, the substrate underneath it, and a written 365-Day Done Right Promise. If the work fails inside that window, we come back and fix it at no charge.
DIY or Call Us?
You can safely check for visible cracks, test your doors and windows for binding, and look for condensation or caulk separation. Those are diagnostic, and they tell you what you’re dealing with. What you shouldn’t do is attempt to relevel a settling addition, re-cut Cambria slabs on-site, or run new electrical to an ADU yourself. Cambria is engineered stone and it requires diamond tooling and correct seam adhesive work. A visible crack near an electrical outlet or a gas line inside an ADU is genuinely dangerous, and that’s a call you should make to a trained professional before anything else. Give us the straight story on what you need, and we’ll give you the straight number on what it costs. Call (254) 527-5340 if you want us to look at it.
FAQs

Cambria quartz is rated to last 25 to 30 years or longer with normal use, and its non-porous surface resists the humidity and moisture problems that warp laminate and stain natural stone in Houston’s climate. The countertop will generally outlast the cabinetry underneath it, which is why proper substrate prep matters more than the slab itself.
Small chips and scratches can sometimes be filled and polished by a fabricator, but structural cracks across a seam or stress fractures from slab movement usually require replacing the affected section. The honest answer depends on where the crack is and whether the underlying cabinet or floor is still moving.
Most single-room additions take 8 to 14 weeks from permit approval to final walkthrough, while a full ADU with its own kitchen and bath typically runs 5 to 9 months. Houston weather and soil conditions can push foundation work, but we write a defined arrival window and a finished scope into every contract.
We order Cambria slabs per project from our local Houston fabricator partner, which keeps your slab matched to the specific design, finish, and thickness your layout calls for. We also work with KraftMaid, Silestone, and Kohler products in the same projects, so your addition’s materials come from recognized trade brands backed by their own warranties alongside ours. Call (254) 527-5340 for an exact quote on your Cambria addition or ADU, and we’ll give you a written number you can hold us to.
Written by Trevor Nash, Owner, Penhallow Remodeling Houston at Penhallow Remodeling Houston, serving Houston and nearby areas.


