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 San Antonio
Home additions in San Antonio typically run $180 – $420 per square foot depending on whether you’re going up with a second story, out with a ground-floor bump-out, or converting a garage into living space. Our Home Addition Contractor team at Seedling ADU San Antonio works across Bexar County, from the bungalows of Beacon Hill to the sprawling lots of Stone Oak. We’re headquartered here in San Antonio, dispatching local crews who know what these houses look like behind the drywall. Call (210) 981-6358 to schedule a free estimate, and you’ll get a written price before any wall is opened.
Why Seedling ADU San Antonio Is San Antonio’s Preferred Home Addition Contractor Company
San Antonio homeowners keep calling us back for one reason: we write down what the job will cost before the first tool comes off the truck. That matters here more than most cities, because the housing stock across Jefferson, Monte Vista, and Beacon Hill hides things behind plaster and shiplap that a drive-by quote will miss. Our crews have opened enough 1920s and 1940s San Antonio bungalows to know what a permit-triggered inspection will flag.
Ben Ortega leads our San Antonio operation, and his approach is uncomplicated. Written pricing upfront, a clean-up photo before the crew leaves, and shoe covers on every pair of boots that crosses your threshold. The 365-Day Done Right Promise backs every addition, garage conversion, and second-story build we finish. If something isn’t right, we make it right, in writing, for a full year after completion. San Antonio customers also get a live person on the phone 24/7 during their build, not a voicemail tree.
We work in San Antonio’s older neighborhoods every week. That means we know the inspectors, we know the permit office’s expectations for historic district work, and we know that a home near Woodlawn Lake built in 1940 will open up differently than a 1980s tract house off Loop 1604. Local knowledge is the difference between a contract that holds and a contract that grows a second head.
Second Story Addition Contractor in San Antonio
A Second Story Addition Contractor in San Antonio has to contend with a specific reality: many of our inner-ring homes were framed when 2×6 ridge beams and knob-and-tube wiring were standard, and neither is going to pass a modern structural or electrical inspection. Going up is often the smartest way to add bedrooms without sacrificing yard space, which is why it’s so popular in neighborhoods like Jefferson and Monte Vista where lots are tighter and front setbacks are protected.
What Opening the Ceiling Reveals
On a recent second-story addition in Beacon Hill, our crew opened up a 1920s bungalow on West Woodlawn Avenue and found knob-and-tube wiring feeding three rooms and a sagging 2×6 ridge beam in the attic. The permit triggered a full rough-in inspection, so we scoped the rewire and a flush-beam replacement before any drywall came down. The new space passed final on the first visit. That’s how we work: the surprise gets priced and approved in writing before we touch it, never after.
The San Antonio Cost Picture
Second-story additions in San Antonio run $220 – $420 per square foot. The range is wide because the structural reinforcement, the rewire, and the stairwell connection vary dramatically by house age. A 1990s build in Alamo Ranch needs far less than a 1925 Craftsman in Alta Vista. But here’s the thing: we write a repair allowance into the contract before we open the roof, so you’re planning for the fix, not reacting to it.
Garage Addition Contractors in San Antonio
Garage Addition Contractors in San Antonio have a unique opportunity in this city: many inner-ring neighborhoods, including Jefferson and Beacon Hill, retain original alley-loaded garage access from the 1920s and 1940s. That’s a code-friendly pathway to add square footage without touching the front elevation. No zoning fight, no historic design review drama, just a garage conversion or garage-top addition that preserves the street view your neighbors already know.
Alley-Loaded Opportunity
If your home faces a protected front setback but your garage opens onto an alley, you can convert that garage to living space or build above it with far fewer hurdles than a front-facing addition would trigger. Monte Vista’s historic design guidelines are strict about the front. They’re quiet about the back. Smart San Antonio homeowners are using that to their advantage.
What a Garage Addition Costs Here
Garage conversions and garage-top additions in San Antonio run $150 – $280 per square foot for a conversion and $200 – $350 per square foot when you’re adding a second level. Foundation work matters more than most people expect, especially on the expansive clay soils in San Antonio’s outer rings. We review the slab before we quote, not after we start.
Trusted Brands We Service in San Antonio
Seedling ADU San Antonio works directly with Plant Prefab, Abodu, and James Hardie materials, which means San Antonio homeowners aren’t limited to whatever a builder prefers to sell. If you’ve been researching prefab panels or fiber-cement siding for your addition, we can quote those products specifically. We keep local familiarity with these systems so the turnaround on specifications, lead times, and installation details is handled by people who’ve done it here, in this climate, on these lots.
Common Home Addition Contractor Problems We See in San Antonio Homes
- Flat-price quotes on pre-1960 bungalows that don’t survive first contact. We’ve seen too many San Antonio families get a handshake number, only to find a surprise change order for knob-and-tube rewire after the walls are open. Our contracts carry a written repair allowance so the price moves only when you approve it in writing.
- Edwards Aquifer recharge zone violations on the northwest side. Adding roof area near Helotes or along the I-10 corridor without a compliant stormwater plan can fail drainage inspection. We scope the drainage plan before the permit application goes in, not after the roof is on.
- Front-facing additions that hit a historic district wall. In Monte Vista and parts of Jefferson, a front addition can stall in design review for months. An alley-loaded garage conversion often clears without a fight. We’ll tell you which path is more realistic on your lot before you commit emotionally or financially.
- Expansive clay that shifts slabs in the outer rings. Homes built in the 1970s-1990s across San Antonio’s outer neighborhoods sit on clay that swells and contracts. A room addition without a foundation review can separate at the seam within two seasons. We bring in a soils assessment whenever the lot history warrants it.
Pricing for Home Addition Contractor in San Antonio, TX
Here’s what families in San Antonio should expect, in real numbers. Ground-floor room additions run $180 – $300 per square foot. Bathroom additions run $220 – $380 per square foot. Sunroom additions run $150 – $250 per square foot. Bump-out additions run $160 – $280 per square foot. Second-story additions run $220 – $420 per square foot. Garage conversions run $150 – $280 per square foot.
The spread reflects what’s inside your walls, not what we feel like charging on a given day. A 1985 home in Cibolo needs less hidden work than a 1920s foursquare in Beacon Hill. Every project gets a written price before any work starts, plus the 365-Day Done Right Promise after the final walkthrough. Call (210) 981-6358 for your free estimate.
We Also Serve Cities Near San Antonio
Our crews serve Home Addition Contractor in San Antonio and the surrounding communities, including Universal City, Helotes, Cibolo, and Floresville. If you’re on the edge of Bexar County and wondering whether we’ll come out, the answer is yes, and the consultation is free.
Serving San Antonio, TX - Our Local Coverage Area
We’re based in the San Antonio 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 San Antonio
Yes, in most cases, because a permit-triggered rough-in inspection will flag active knob-and-tube wiring, and San Antonio code requires it be decommissioned in any area opened for the addition. The cost of that rewire is something we scope before walls come down, not after. Call (210) 981-6358 to get a written number on your specific home.
Yes, if the addition stays within the existing footprint and respects the front elevation, a second-story addition can often proceed without a setback variance. The key is keeping the front roofline and porch character intact. We’ve steered several Jefferson homeowners through this exact review. Call (210) 981-6358 and we’ll walk your lot with you.
Yes, especially on the expansive clay soils common across San Antonio’s outer neighborhoods, where slabs shift seasonally even when they look intact from the outside. A foundation review before a room addition is a few hundred dollars that can prevent a seam separation that costs thousands to fix. We include this in our written quote when the lot and house age call for it.
An alley-loaded garage can often be converted to a garage apartment or rebuilt as a two-story addition with a far lighter review than a front-facing build, because the alley access preserves the front elevation the city protects. Near Woodlawn Lake, we’ve seen these pass where a front-facing addition stalled. Call (210) 981-6358 and we’ll tell you what your specific lot can support.
Any added roof area in the recharge zone, common on San Antonio’s northwest side near Helotes and the I-10 corridor, must include a stormwater plan that keeps runoff on your lot or routes it to a compliant system. Failure there fails the drainage inspection, full stop. We design that plan into the permit package from the first draft. Call (210) 981-6358 for an estimate that includes it.
Call (210) 981-6358 to schedule your free estimate. We’ll walk your San Antonio lot, talk through what the permit will trigger, and hand you a written price before any work starts.
Written by Ben Ortega, Owner at Seedling ADU San Antonio, serving San Antonio’s homeowners.
