A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted Home Addition Contractor for San Antonio Homeowners
Adding square footage to your San Antonio home comes down to one question: who will treat your house the way you would? Floors protected, schedules respected, no surprise line items after the crew shows up. That is exactly where our Home Addition Contractor in San Antonio team begins. Since 2001, our crews have built room additions, sunrooms, second stories, and garage conversions across San Antonio, Alamo Heights, and Terrell Hills and every one of those projects started with a written price before a single tool left the truck. Ben Ortega leads our San Antonio team, and the 365-Day Done Right Promise backs every completed job in writing. If it is not done right, we make it right. Call (210) 981-6358 for a free estimate.
Sunroom Addition
A sunroom addition in San Antonio adds a year-round living space that captures Hill Country light without forcing your family through a full home remodel. Homeowners in neighborhoods like Timberwood Park and Scenic Oaks choose sunrooms when they want a breakfast nook, play space, or reading room that feels connected to the yard. Seedling ADU San Antonio prices sunroom additions from $45,000 to $85,000 depending on glazing, foundation work, and whether you choose a prefab or stick-built shell. Our crew works with James Hardie siding and energy-efficient glazing so the room stays usable through July heat and the rare January freeze.
Glass Selection and Climate Control
San Antonio summers punish poorly glazed sunrooms. We spec low-E double-pane glass with proper ventilation and ceiling fans as standard, because a sunroom that hits 110 degrees in August is not a room anyone uses. Shade orientation matters, and we review how afternoon sun hits your lot before recommending window placement.
Foundation and Flooring Choices
Slab-on-grade sunrooms cost less than raised foundations, but drainage patterns in areas like our Home Addition Contractor in Helotes service area and Fair Oaks Ranch can shift that math quickly. We check your existing roofline, soil movement, and downspouts before quoting, and we protect your existing floors with drop cloths and shoe covers the entire time our crew walks through your home.
Room Addition Contractor
A room addition contractor in San Antonio handles the planning, permitting, and building of any ground-floor living space added to your home, whether it is a home office, playroom, guest suite, or expanded family room. Most San Antonio homeowners call us when their family has outgrown the original floor plan but moving is off the table because of school districts, lot value, or the cost of buying up in a tight market. Seedling ADU San Antonio prices room additions from $60,000 to $150,000 depending on square footage, plumbing, electrical runs, and finish level. Every quote is written before work begins, and the price on that page is the price you pay.
Permitting and Lot Setbacks
San Antonio permits for room additions move faster when the drawings are right the first time. We pull permits for every ground-floor addition, handle the inspections, and keep you informed when the inspector signs off. Setback rules vary by zip code, and we check your plat before we quote so there are no surprises after framing starts.
Matching Existing Home Details
An addition that looks stapled on hurts resale value. We match your roofline pitch, brick or siding profile, window style, and trim details so the new space reads as original construction. In older neighborhoods around San Antonio, that often means sourcing matching brick or stucco textures, which we do before we break ground.
Second Story Addition Contractor
A second story addition contractor in San Antonio builds upward when the lot cannot grow outward, which is common in compact inner-loop neighborhoods and in Terrell Hills and Alamo Heights where side setbacks eat into usable yard space. Second-story additions run $150,000 to $350,000 in San Antonio depending on structural reinforcement, stair placement, and plumbing runs to a new upper bathroom. Seedling ADU San Antonio manages the engineering, the temporary roof weatherproofing, and the sequence of work so your family can stay in the house while the upper level goes up.
Structural Assessment Before You Commit
Not every slab and frame is built to carry a second floor. We review your original plans, crawl space or slab condition, and wall framing before quoting, because the cost difference between a supported and unsupported second story is the difference between a clean build and a tear-out. If your home needs reinforcement, you will know that cost before work starts, not after a lumber delivery shows up.
Protecting the Lower Level During Construction
Building up means living under a work zone, and we plan for that. Dust barriers, nightly clean-up, a photo of the clean-up before the crew leaves, and pet-safe materials where we have a choice. Our crew communicates what is happening each morning before it touches anything, so you are not walking into a surprise staircase hole with kids in the house.
Garage Addition Contractors
Garage addition contractors in San Antonio build attached or detached garages when the original home either lacks one or needs a larger one for extra vehicles, a workshop, or storage. A standard two-car attached garage addition in San Antonio runs $40,000 to $75,000, while a detached garage with a finished interior space above it lands between $70,000 and $120,000. Seedling ADU San Antonio handles the slab, framing, electrical, and garage door installation, and we quote the full job in writing before the first concrete truck arrives.
Detached Workshop and Storage Options
A garage is more than parking in San Antonio. We build detached garages with extra depth for a workbench, storage loft framing, and wider bays for full-size trucks, which matters when your driveway is in Cibolo or Floresville where HOA rules and lot lines vary. If the garage doubles as a shop, we spec the electrical panel capacity for future tools from day one.
Attached Garage Tie-In and Roofline
Attached garages need to match the house or the whole street looks off. We match roof pitch, fascia board width, and siding material so the garage reads as part of the original home. We also review how the new garage affects your existing driveway slope and drainage, which prevents a new garage from turning into a puddle after a heavy San Antonio storm.
Bathroom Addition Contractor
A bathroom addition contractor in San Antonio adds a new full or half bath to a home that has too few bathrooms for the number of people living in it, a common pinch point in three-bedroom, one-bath homes across mid-century San Antonio neighborhoods. Bathroom additions run $30,000 to $65,000 depending on whether the new bath ties into existing plumbing or needs a new drain line, vent stack, and water supply run. Seedling ADU San Antonio quotes the plumbing, tile, fixture, and electrical work as one written price so you know the full cost before we open the first wall.
Plumbing Runs and Venting Reality
A bathroom in the wrong place costs two or three times more than a bathroom near an existing stack. We walk your house to find the nearest drain location and vent route before we quote, and if the best spot is across the slab, we tell you that cost honestly. No surprise change orders after the concrete saw comes out.
Finish Level and Daily-Use Durability
Family bathrooms in San Antonio need surfaces that survive kids, humidity, and hard water. We steer clients toward dense porcelain tile, properly sloped shower pans, and exhaust fans that actually move air. The Cedarwell Care Promise applies inside your house: shoe covers, drop cloths, and a clean-up photo before we leave each day, because bathroom demo dust travels.
Bedroom Addition Contractor
A bedroom addition contractor in San Antonio adds a sleeping room, typically when a family grows or an aging parent moves in and needs a ground-floor suite. A standard bedroom addition runs $50,000 to $90,000 in San Antonio depending on closet size, egress windows, and whether an attached bath is part of the plan. Seedling ADU San Antonio builds bedrooms that meet current egress code, which matters for resale and safety, and we leave the room ready for paint and furniture on the day we hand over the key.
Egress Windows and Code Compliance
A bedroom without a proper egress window is not a bedroom on paper and cannot be listed as one. We size egress windows to code, position them for natural light, and handle the inspections so your new bedroom counts legally. This is a detail cheap contractors skip, and it surfaces later at resale in the worst way.
Ground-Floor Guest and In-Law Suites
San Antonio families adding a bedroom often add it for an aging parent or a returning adult child. We plan for wider doorways, grab-bar blocking in the walls, and a closet layout that works for someone who is not eight years old. If the room needs an attached bath, we price that honestly as part of the same written estimate, not as an add-on later.
Brands We Service
We work with James Hardie fiber cement siding and trim on nearly every addition we build in San Antonio, because Hardie holds its paint and resists the humidity swings that chew up cheaper siding in this climate. We also finish room additions with James Hardie panel profiles that match your existing exterior, so the new space looks original from day one.
For clients who want a faster build or a factory-built shell, we work with Plant Prefab and Boxabl for additions that ship as engineered modules and get finished on-site by our crew. Whether you have a James Hardie exterior, a Plant Prefab shell, or any other make, we have the crew and the process to build it right.
Signs You Need a Pro Right Now
- Your family has outgrown the floor plan. Kids sharing rooms, a home office in the dining room, or a parent moving in are all signs the square footage is no longer working. A room addition solves this without the cost and disruption of a move, but it needs a contractor who plans the space for how your family actually lives.
- You priced a move and it does not make sense. San Antonio property values in established neighborhoods keep climbing, and selling means paying transfer costs, a new mortgage rate, and a new school district. Adding square footage to a home you already like often lands cheaper per square foot than buying up.
- Your garage is full and the cars are in the driveway. Storage creep is a signal the home runs out of room before the family does. A garage addition or a converted space restores order, but only if it is built with the right slab, electrical, and door sizing for your vehicles.
- Bathroom lines form every morning. One bathroom for four or five people stops being a quirk and starts being a daily bottleneck. A bathroom addition adds real daily function, and in San Antonio’s older homes, it typically pays back at resale.
- You have talked about adding a room for over a year. The longer a home addition waits, the more material and labor prices shift. A written estimate from Seedling ADU San Antonio gives you a real number to plan around instead of a vague “someday” that keeps sliding.
Our Process, Step by Step
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Free on-site walkthrough. We walk your San Antonio home, measure the space, check the lot, and listen to how your family needs the addition to function. You get a written price after this visit, not a range with fine print.
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Written estimate and scope review. Ben Ortega reviews every estimate before you see it. The price covers materials, labor, permits, and finish work. We sit down and walk you through it line by line so there are no surprises.
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Permits and drawings. We prepare the drawings and pull San Antonio permits for your addition. We handle the inspections and keep you posted when each one passes. Setbacks, egress, plumbing, and structural loads are all checked before work starts.
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Construction with the Cedarwell Care Promise. Our background-checked, uniformed crew arrives in marked vehicles, lays drop cloths across every path through your home, and puts on shoe covers at the door. We use pet-safe products where there is a choice, keep noise near bedrooms to reasonable hours, and send you a photo of the clean-up before the crew leaves each day.
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Walkthrough and 365-Day Done Right Promise. We walk the finished addition with you and build a punch list if anything needs attention. Every job is backed in writing by the 365-Day Done Right Promise: if it is not done right, we make it right.
How Much Does Home Addition Contractor Cost in San Antonio?
A typical home addition in San Antonio runs $30,000 to $350,000 depending on the type of space and the complexity of the work. Here is how common projects break down in this market:
- Sunroom addition: $45,000 – $85,000
- Room addition (single ground-floor room): $60,000 – $150,000
- Second story addition: $150,000 – $350,000
- Garage addition (attached two-car): $40,000 – $75,000
- Bathroom addition: $30,000 – $65,000
- Bedroom addition: $50,000 – $90,000
What moves the price: whether the addition ties into existing plumbing and electrical or needs new runs, foundation type, roof intersection complexity, finish level, and whether the lot conditions require extra engineering. Clay soils in parts of San Antonio can require deeper footings, which is a known local cost driver we price honestly. The way to avoid overpaying is to get a written, line-item price before work starts and to work with a contractor who does not write change orders for things that should have been in the first quote. Your free estimate from Seedling ADU San Antonio includes the full scope, the permit plan, the Home Addition Contractor Maintenance Checklist for San Antonio Homeowners, and the 365-Day Done Right Promise in writing. Call (210) 981-6358 to schedule yours.
Our Service Area Near San Antonio
Seedling ADU San Antonio builds home additions across San Antonio and the surrounding Hill Country communities, including New Braunfels, Selma, Boerne, Helotes, Fair Oaks Ranch, Terrell Hills, Universal City, Cibolo, Floresville, Timberwood Park, and Scenic Oaks. We also serve as a Home Addition Contractor in New Braunfels for families up the I-35 corridor and a Home Addition Contractor in Selma for households near Randolph AFB. From our home base in San Antonio, we bring the same written pricing and Cedarwell Care Promise to every project, and you can read more about what we do on our Home Addition Contractor in San Antonio page.
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.
Frequently Asked Questions About Home Addition Contractor in San Antonio
A Home Addition Contractor in Universal City or San Antonio is a licensed builder who plans, permits, and constructs new living space attached to your existing home. In San Antonio, that work includes sunrooms, ground-floor room additions, second stories, garage additions, and new bathrooms or bedrooms. Seedling ADU San Antonio handles every step, from drawings and permits to the finished trim, with a written price before work starts. Call (210) 981-6358 to talk through what your lot can support.
A typical ground-floor room addition in San Antonio takes 8 to 16 weeks from permit approval to final walkthrough, depending on plumbing and electrical scope. Second-story additions run longer, often 4 to 6 months, because of structural work and roof sequencing. We give you a written schedule with your estimate and update you as inspections pass. Call (210) 981-6358 for a timeline specific to your project.
Home additions in San Antonio range from about $30,000 for a simple bathroom addition to $350,000 for a full second story. Sunrooms run $45,000 to $85,000, single room additions $60,000 to $150,000, and garage additions $40,000 to $120,000 depending on size and finish. Your written estimate from Seedling ADU San Antonio includes permits, materials, labor, and the 365-Day Done Right Promise. Call (210) 981-6358 for an exact quote.
Yes, we use James Hardie fiber cement siding and trim on most of the additions we build in San Antonio, especially when the existing home already has Hardie or a similar profile. James Hardie holds paint and resists the humidity and heat swings this region throws at siding. We also work with Plant Prefab and Boxabl for factory-built addition shells. Call (210) 981-6358 to discuss materials for your addition.
If an addition or structural issue developed mid-project or a previous contractor left work unfinished, call us. Our live person answers 24/7 during active builds, so you are never chasing a voicemail tree when something needs attention. If it is an active safety issue with framing, electrical, or gas lines, a trained professional should assess it before anyone re-enters the space. Call (210) 981-6358 and we will walk you through next steps.
Every completed addition from Seedling ADU San Antonio is covered by the 365-Day Done Right Promise in writing. If something is not done right within the first year, we come back and make it right. That covers our workmanship on the addition, the finishes, and the details we touched inside your home. Call (210) 981-6358 and we will walk you through exactly what the promise includes.
Clear the construction path, move breakable items away from shared walls, and keep pets in a closed room or with a sitter during work hours. Our crew handles the rest: drop cloths on every floor path, shoe covers at the door, pet-safe products where there is a choice, and a clean-up photo before we leave each day. We will tell you what to expect in writing before the first day. Call (210) 981-6358 to schedule your free estimate and prep walkthrough.
Schedule Your Home Addition Contractor Service in San Antonio Today
Adding a room, a bathroom, or a second story changes how your family lives for years. Get a written price before work starts, a crew that protects your floors and air quality, and a 365-Day Done Right Promise in writing. Call Seedling ADU San Antonio at (210) 981-6358 to schedule your free, no-obligation estimate. Ben Ortega and our San Antonio team are ready to walk your home and hand you a real number.
Written by Ben Ortega, Owner at Seedling ADU San Antonio, serving San Antonio and surrounding Hill Country communities.
