







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateFast, Reliable Home Addition Contractor Across Alvin
Home additions in Alvin run anywhere from $85,000 for a modest bump-out to $240,000+ for a full second-story build, and the single biggest cost driver here isn’t lumber or labor. It’s the soil under your slab. Alvin sits on expansive clay that swells and shrinks with every wet-dry cycle the Gulf Coast throws at it, and a foundation spec that works fine in Friendswood can crack within two winters in Alvin if nobody ran a geotechnical report first. That’s the kind of thing we handle before we ever submit a permit, because we’ve watched too many homeowners get burned by contractors who treated Alvin like just another Houston suburb. Russ Delmar and the Lodgewick crew know the difference. Call (361) 326-2313 and we’ll put a written price in front of you before any work starts.

Why Lodgewick ADU Houston Is Alvin’s Preferred Home Addition Contractor

We’re part of the Kingswell family of home-service companies, founded in 2010, and every Alvin project runs under The Kingswell Guarantee: a written price first, a real arrival window, a clean job site, and a written guarantee delivered before the first nail goes in. That’s not marketing copy. It’s the same commitment we’ve made on garage conversions off Highway 35, second-story additions in Oak Hollow, and bathroom additions near Mustang Bayou. When an Alvin homeowner calls us, a live person answers. Always. You’ll talk to someone who knows your street, not a call center reading a script.
Our local reputation in Alvin comes down to two things: we show up when we say we will, and we don’t change the price at the door. The Kingswell Guarantee includes a 365-Day Done Right Promise. If something’s not right within a year, we come back and make it right. Free. That promise is in writing on every single project. We’re not the cheapest contractor in Alvin, and we’re fine with that. We’re the one who puts the number in writing and stands behind it.
Bathroom Addition Contractor in Alvin
A Bathroom Addition Contractor in Alvin is doing more than roughing in plumbing and tiling a shower. We’re calculating how a new slab tie-in behaves on expansive clay, verifying the wastewater line slope matches Brazoria County code, and making sure the wall assembly handles the humidity a Gulf Coast bathroom produces year-round. A full bathroom addition in Alvin typically runs $45,000 to $85,000 depending on fixture grade, whether we’re adding a tub or walk-in shower, and how far the new plumbing stack is from your existing line. That’s a real range, not a teaser number.
Soil-Sensitive Slab Work
Every bathroom addition in Alvin starts with a look at what’s under the floor. If the soil report shows high plasticity index clay, we spec a post-tension slab or piers rather than a standard pour. It costs more up front and saves you a cracked floor and a re-leveling bill later.
Ventilation That Actually Moves Air
A bathroom that fogs up and stays damp for hours is a mold problem waiting to happen in Alvin’s climate. We size the exhaust fan to the room’s cubic volume, not the cheapest unit on the shelf, and run the duct to the exterior with a damper. This is standard practice for us, not an upgrade pitch.
Bedroom Addition Contractor in Alvin
A Bedroom Addition Contractor in Alvin has to think about egress windows, HVAC load calculations, and whether the existing roofline can tie in cleanly or needs a cricket to shed water properly. A ground-floor bedroom addition in Alvin typically runs $60,000 to $130,000. The range depends on whether we’re converting conditioned space or building from the dirt up, ceiling height demands, and how much foundation engineering the soil report requires.
Foundation Engineering First
Our crew recently scoped a bedroom addition in the Oak Hollow subdivision off Highway 6, where we had to re-engineer the foundation after soil testing showed 4 feet of expansive clay. We switched to a post-tension slab and piered footings, which added 12 days to the permit phase but prevented future slab heave. The homeowner wasn’t thrilled about the timeline. They were glad someone caught it before the pour.
HVAC and Comfort Loads
Adding a bedroom changes your HVAC balance. We calculate the new room’s heating and cooling load and size duct runs accordingly, rather than tapping off the nearest trunk line and hoping for the best. In Alvin’s summer heat, a bedroom that can’t hold 74 degrees isn’t a bedroom. It’s a storage room with a bed in it.

Trusted Brands We Service in Alvin
Lodgewick ADU Houston works hands-on with leading prefab and panelized building systems, including Boxabl, Plant Prefab, and Tuff Shed structures. For Alvin homeowners, that means we can often trim weeks off a build by ordering factory-cut panels that arrive ready to set, rather than stick-framing every wall on site in Gulf Coast humidity. We know how these systems perform on clay soils and under Alvin’s 110 mph wind zone mandate, and we spec the right tie-downs and sheathing to match. If you’ve been researching a prefab addition or a Tuff Shed conversion, we can give you a straight answer about what works here and what doesn’t. Call (361) 326-2313 to talk it through.
Common Home Addition Contractor Problems We See in Alvin Homes
- Slab cracks from skipped soil reports. The most expensive mistake we see is a standard slab poured on Alvin’s expansive clay. Within two years, the slab heaves and cracks, doors stop latching, and the fix costs more than the original foundation. A geotechnical report is roughly $1,500 to $3,500. A re-leveled slab starts around $12,000. Do the math.
- Floodplain review surprises. Lots near Mustang Bayou or within Brazoria County’s mapped flood zones can trigger a floodplain development permit review that adds 3 to 6 weeks to the permit phase. Contractors who don’t check this early get stuck after demolition’s done and the homeowner’s family is living in a construction zone.
- Windstorm inspection misses. Alvin’s in a 110 mph wind zone, so any addition with a new roof plane or structural wall requires windstorm-rated roof ties and sheathing inspections. Skipping this or framing to outdated standards fails inspection and means tearing out work you already paid for.
- Contractor no-shows and price creep. This one’s not about soil or code. It’s about contractors who give a low verbal number to get the job, then hit you with change orders. The Kingswell Guarantee puts the price in writing before work begins. No exceptions. No door-price changes. It’s the only way we work.
Pricing for Home Addition Contractor in Alvin, TX
Here are honest ranges for Alvin’s market. A bump-out addition runs $45,000 to $90,000. A bathroom addition runs $45,000 to $85,000. A bedroom addition runs $60,000 to $130,000. A sunroom addition runs $40,000 to $95,000. A second-story addition runs $150,000 to $240,000. The variables are foundation engineering on clay soil, windstorm-rated framing, material grade, and permit fees. We give you a written line-item price before any work starts, and that number doesn’t change unless you change the scope. Estimates are free. Call (361) 326-2313 and we’ll walk your lot and give you real numbers, not a vague “somewhere between.”
We Also Serve Cities Near Alvin
Beyond Alvin, our crews regularly work in Manvel, Friendswood, Santa Fe, and Dickinson. If you’re in one of those areas and looking for a Home Addition Contractor who writes the price down before the work starts, call (361) 326-2313. We’ll tell you straight whether your project is something we take on and what it’ll cost.
Serving Alvin, TX - Our Local Coverage Area
We’re based in the Alvin area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Home Addition Contractor in Alvin
Maybe. Brazoria County reviews floodplain status on all substantial additions, and being away from a visible creek doesn’t automatically exempt you. Lots in FEMA Zone AE or near Mustang Bayou drainage paths usually trigger a floodplain development permit review. That review can add 3 to 6 weeks to your permit timeline. Call (361) 326-2313 and we’ll check your lot’s flood zone status before you commit to anything.
Alvin and Brazoria County typically complete residential addition permit reviews in 3 to 8 weeks, depending on floodplain status and whether a soil report or windstorm review is required. Houston proper often runs 6 to 12 weeks for comparable scope. Alvin can be faster, but floodplain reviews and windstorm inspections add time here that a Houston contractor might not anticipate. We build that into your schedule up front so you’re not surprised.
Usually no. The slab under a covered patio was poured as a non-conditioned exterior slab, often 4 inches thick with no vapor barrier or rebar to the same spec as living space. Conditioning the room changes the thermal and moisture profile, and Alvin’s expansive clay makes an underdesigned slab crack quickly. We’ll run a site check, and if the existing slab can’t be verified, we’ll price new footings and a proper slab tie-in. Call (361) 326-2313 for a free assessment.
Yes, a home addition increases your property’s assessed value in Alvin, and therefore your Brazoria County property taxes. The increase depends on the addition’s square footage and finished quality. A $60,000 bedroom addition might add $900 to $1,500 annually in property taxes at Alvin’s current rates, but you should confirm with the Brazoria County Appraisal District. We can’t give tax advice, but we can give you accurate finished-square-footage numbers to take to a tax professional.
Yes, if the addition includes any new roof plane, exterior wall, or structural connection. Alvin is in a 110 mph wind zone, and Brazoria County enforces windstorm-rated sheathing, roof ties, and inspection sequencing even on small additions. A bathroom addition that ties into the existing roofline still needs the roof tie inspection signed off before drywall goes up. We schedule these inspections in the right order so you don’t have to tear out finished work. Call (361) 326-2313 to talk through your specific scope.
Written by Russ Delmar, Owner at Lodgewick ADU Houston, serving Alvin since 2010.








