Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Cover Home Additions & ADU: The Houston Owner’s Guide
Home additions and ADU construction in Houston typically run $45,000 – $130,000 installed, depending on square footage, foundation type, and finish level. Most owners discover they’ve outgrown their current footprint long before the first permit is pulled – a spare bedroom that became a home office, aging parents moving in, or a rental income opportunity that keeps getting put off. As a remodeling company that specializes in whole-home projects, we see the same pattern in neighborhoods from Meyerland to The Heights: the need arrives quietly, and by the time it’s urgent, the project scope has doubled. Trevor Nash and our crew have built enough additions across Houston to know that the soil under your slab tells us more about the project than the floor plan does.
Key takeaways:
- Home additions in Houston run $45,000 – $130,000; standalone ADUs start around $90,000 and top out near $220,000 for a fully finished unit
- Foundation work is the biggest cost driver – Houston’s expansive clay soil means pier-and-beam or slab decisions affect your final price by $8,000 – $20,000
- We write your price down before any work starts, and the 365-Day Done Right Promise backs the finished job in writing
- Permits, structural engineering, and utility connections are handled by our team – not left for you to chase
Which Cover Models This Applies To
When homeowners talk about “Cover” projects, they’re usually describing a home addition or accessory dwelling unit sized to their lot and their family structure – and the planning approach matters more than a model number. Unlike a cabinet line or countertop brand, there’s no single Cover catalog number to match. What we match instead is the existing roofline, foundation type, plumbing stack location, and electrical panel capacity. That’s the real compatibility question. A two-story addition over a pier-and-beam foundation in Montrose behaves completely differently than a single-story bump-out on a post-tension slab in Katy.
Our team also works with KraftMaid, Cambria, and Silestone products, so if your addition or ADU involves new cabinetry or quartz surfaces, we coordinate those specifications from the start rather than forcing a retrofit later. Independent note up front: Penhallow Remodeling Houston is not affiliated with Cover – we’re a local general contractor who builds additions and ADUs to Houston permitting standards and stands behind the finished structure.
Styles & brands we work with
Signs Your Cover Home Additions & ADU Is Failing
- Doors that stick or won’t latch cleanly. Houston’s clay soil expands and contracts with rainfall, and this movement shows up first at door frames and drywall corners. If doors that closed fine last summer now drag, the foundation or framing may be shifting more than normal.
- Hairline cracks that widen past a dime’s width. Surface cracks in drywall are cosmetic; cracks that run through brick, follow mortar joints, or keep reappearing after patching point to structural movement that a new addition must account for before you build.
- Uneven floors in the older section where new meets existing. The seam between original house and addition is the most vulnerable point in any Houston project. If your slab has settled at the transition, any new work will need leveling and possible piering first.
- Moisture or mildew along the baseboards of an existing addition. Poor drainage or a missing vapor barrier under the slab lets groundwater wick up through concrete. Fixing this before framing a new ADU saves you from trapping moisture inside the new walls.
- Roof leaks at the tie-in point. Where the new roofline meets the old is where flashing fails most often. Standing water after storms, stains on ceiling drywall, or daylight visible at the ridge are all signs the flashing was never installed properly and the underlying framing needs inspection.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
In Houston, a home addition runs $45,000 – $130,000 installed, while a full ADU with kitchen and bath starts at $90,000 and can reach $220,000. The number moves based on three things: foundation work (expansive clay means deeper piers or a slab designed to float), finish level (builder-grade trim versus custom cabinetry), and utility scope (whether we’re tapping into existing plumbing or running new sewer and electrical service).
| Project Type | Houston Installed Range |
|---|---|
| Single-room home addition | $45,000 – $85,000 |
| Primary suite addition | $70,000 – $130,000 |
| Garage conversion (finished) | $30,000 – $80,000 |
| ADU construction (full unit) | $90,000 – $220,000 |
Every project gets a written price before any work starts – not a range, not a verbal ballpark. That number includes permits, plans, materials, labor, and the cleanup. You’ll see every line item explained before you sign. The 365-Day Done Right Promise covers the workmanship in writing: if something fails within the guarantee period, we come back and fix it at no charge. If a repair fails after we’ve returned once, the second visit is also free. That’s been the Kingswell standard since 2004.
DIY or Call Us?
There are things you can check before calling: walk the perimeter after a heavy rain and note where water pools; mark any new foundation cracks with painter’s tape and the date so you can track movement; check that your downspouts extend at least four feet from the slab. Those observations help us diagnose what’s happening before we ever dig. What you shouldn’t do is jack up a settling slab, cut into load-bearing walls, or tie into your own electrical panel to add circuits for a new room. These are structural and life-safety trades – one wrong move with a load path, and you’ve turned a $50,000 project into a $150,000 repair. Framing, foundation work, and panel work belong to licensed pros with the tools to test the load before they change it. And to be blunt: Houston’s permitting office won’t sign off on work done by an unlicensed homeowner anyway.
If you’re seeing movement, moisture, or you’re ready to plan a for-real addition, call (254) 527-5340 and tell us what’s going on. We’ll set a time that works, walk the site, and give you a written number.
FAQs
Most additions take 3 to 6 months from permit approval to final walkthrough; ADUs run 5 to 9 months depending on utility work and finish level. The time is driven by foundation curing and Houston’s permit inspection schedule as much as by the framing crew. Call (254) 527-5340 for a timeline based on your project – estimates are free.
Yes – if the framing, slab, and roof structure are sound, we can reframe tie-ins, replace flashing, re-level floors, and correct drainage without tearing everything down. A full rebuild is only the right call when the structural core has failed or the original work was never permitted. We’ll tell you which you’re dealing with and put the number in writing.
We do. Permits, structural engineering stamps, and utility connection approvals are handled by our team for every project. If the work needs a third-party inspection, we schedule it and stand behind the result – a permit pulled and an inspection passed is part of the written guarantee.
Not unless you change the scope. The number on your written estimate is the number on your invoice. If you add square footage or upgrade materials mid-project, we’ll write a change order and you approve it before any new work starts. That’s the Kingswell Way – say the price before the work, and hold to it.
Give me the straight story on what you need, and I’ll give you the straight number on what it costs. Call (254) 527-5340 to schedule a free estimate for your Houston home addition or ADU.
Written by Trevor Nash, Owner, Penhallow Remodeling Houston at Penhallow Remodeling Houston, serving Houston and nearby areas.
