







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 Selma
A home addition in Selma typically runs $110,000 – $230,000 for a thoughtfully built room or casita, and the real variable isn’t labor hours; it’s how carefully the foundation is engineered for our clay soil and whether the price for custom materials is locked in writing before anyone orders anything. That’s the work we do. Seedling ADU San Antonio serves Selma homeowners from Retama Springs to the neighborhoods along Evans Road, and we bring the same written-price discipline to a bump-out as we do to a full detached casita. If you’re planning an addition, call (210) 981-6358 and we’ll walk your lot with you before you spend a dollar.
Why Seedling ADU San Antonio Is Selma’s Preferred Home Addition Contractor Company

Selma homeowners call us because we talk about what actually happens on their lot: where the foundation joints go, how long the millwork takes, what the HOA will ask about exterior materials. We’ve coordinated additions in neighborhoods across Selma, and the same concerns come up: clay soil that moves, newer slab-on-grade homes that need careful structural ties, and schedules driven by specialty material lead times rather than crew availability.
Our Selma customers routinely mention three things after the job closes. First, the written price held; there were no surprise line items when custom cabinets or architectural glass arrived. Second, the crew left the home the way our Cedarwell Care Promise requires: shoe covers and drop cloths inside, pet-safe products where there’s a choice, and a photo of the clean-up before the crew pulled away. Third, a live person answered the phone whenever they called during the build. Not a voicemail tree. Ben Ortega, who leads our team, holds every Selma project to that standard personally.
We’re the Home Addition Contractor team Selma families call when they want the addition to feel like it was always part of the house, not a box bolted onto the back of it.
Second Story Addition Contractor in Selma
Second Story Addition Contractor work in Selma means engineering a new second floor onto a slab-on-grade home built after 2000, and that starts with a structural assessment of the existing slab and framing. Most Selma homes from that era can carry a partial second story, but the foundation needs a close look because our clay-heavy soil has been expanding and contracting under the slab since the day the concrete cured. We specify the reinforcement and any needed footing upgrades before we ever talk about floor plans.
What the structural work involves
We open walls at load points, verify the framing and slab condition, and work with a licensed structural engineer to design the tie-in. On a Selma slab that has seen 20 years of clay-soil movement, we often add steel columns and deeper pier supports at the new load path. The goal is a second story that doesn’t transmit movement down into the original first-floor walls.
What it costs and how long it takes
A second-story addition in Selma runs $180,000 – $320,000 depending on square footage and whether you’re adding a primary suite or two bedrooms and a bath. The schedule is usually 14 – 20 weeks. The honest variable is material lead time: custom stair railings, windows sized to match your existing openings, and engineered lumber all sit in someone’s queue. We order those first, after the price is fixed in writing.
Garage Addition Contractors in Selma

Garage Addition Contractors in Selma handle two different jobs: a detached garage addition with living space above it, or an attached garage bump-out that extends the existing footprint. On Selma’s 0.15 – 0.5 acre lots, the detached version usually makes more sense; there’s room, and the HOA covenants in many Selma subdivisions are written to allow it. The slab work is the critical part. We design the new garage slab with movement joints that accommodate our expansive clay rather than fighting it.
Detached garage with a home office or suite above
This is a popular Selma pattern: a two-car garage with a finished room above for an office, a guest suite, or a rental. Because it’s detached, the existing home’s foundation isn’t disturbed, and the new slab can be engineered independently with its own deep perimeter beams. Figure $90,000 – $160,000 for a two-bay version with a finished room above, including electrical and HVAC to the upper level.
Attached garage bump-out
When the addition attaches to the home, we tie the new slab to the existing slab with steel dowels and a movement joint at the transition. The seam is the failure point on this job; cutting corners there means cracks that run from the garage floor into the house slab. $70,000 – $120,000 is the honest range for a one-bay attached bump-out in Selma, finished with hardi-trim and a door that matches the house.
Trusted Brands We Service in Selma
For Selma additions we work regularly with James Hardie siding and trim, because it holds paint and resists our humidity better than most alternatives, and we use Tuff Shed structures when a simple, well-built garage or studio shell fits the budget better than full custom framing. On the prefab side, Boxabl and Plant Prefab are options we’ve specified for Selma homeowners who want a manufactured casita delivered and set on the engineered slab we’ve already prepared. We don’t sell you the brand we prefer to sell; we show you what fits your lot and your HOA’s exterior materials requirements, then price it in writing before anything is ordered.
Common Home Addition Contractor Problems We See in Selma Homes
- Clay-soil slab movement telegraphing into the addition. Selma’s expansive clays swell after rain and shrink in summer. If the new slab isn’t isolated with movement joints and engineered beams, cracks start in the addition and walk right into the original slab.
- Long-lead materials priced after the contract is signed. Custom millwork, architectural glass, and specialty windows have six-to-ten-week lead times. If the price isn’t fixed before ordering, the homeowner absorbs whatever the millshop or glass fabricator charges on delivery day.
- HOA architectural review not completed before foundation work starts. Some Selma HOAs require exterior material approval before any site work. Skipping that step means redoing elevations or, worse, stopping a poured foundation while the review committee meets.
- Slab plumbing conflicts in additions that include a bath or kitchenette. Because most Selma homes are slab-on-grade, adding a drain line means cutting a trench through the existing slab. Rerouting is possible, but it has to be planned and priced before the first cut, not discovered mid-job.
Pricing for Home Addition Contractor in Selma, TX
Here are the numbers Selma homeowners should plan around. A simple room addition like a guest bedroom or office bump-out: $110,000 – $170,000. A bathroom addition with a slab trench for the drain: $70,000 – $110,000. A garage addition, attached or detached: $70,000 – $160,000. A full second-story addition: $180,000 – $320,000. A detached casita with a separate entrance: $140,000 – $260,000 depending on finishes. What moves the number within these ranges is square footage, foundation work required by the clay soil, and your material choices. Custom rift-sawn oak cabinets cost more than painted shaker, and architectural glass pocket doors cost more than a standard French door. We’ll give you a written, line-item price before we order a single long-lead item. Call (210) 981-6358 for a free estimate and we’ll walk the actual scope on your lot.
We Also Serve Cities Near Selma
Our crews work throughout the I-35 corridor and the Hill Country edge. We serve Selma plus San Antonio, New Braunfels, Boerne, and Helotes, with local crews familiar with each area’s soil conditions and HOA patterns. If you’re in a neighboring city and planning an addition, the same written-price promise and the same Care Promise apply.
Serving Selma, TX - Our Local Coverage Area
We’re based in the Selma 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 Selma
Selma’s expansive clay soils require foundation designs with movement joints and deeper perimeter beams to accommodate seasonal swelling and shrinking, and skipping that engineering leads to slab cracks that run from the addition into the original home. We design every Selma slab addition as a separate island tied with dowels at the seam, never as a continuous pour that fights the soil. Call (210) 981-6358 and we’ll explain what your specific lot needs.
Custom millwork, architectural glass, and specialty windows drive the schedule; a custom cabinet order from the San Antonio millshops we work with is routinely a six-week lead time, and glass pocket door systems can run eight. That’s why we fix your price in writing before ordering those materials, so the only schedule variable is the supplier’s queue, not your budget. We coordinate the order dates so your addition doesn’t stall waiting on a single item.
Many Selma subdivisions, including Retama Springs, have permissive HOA covenants that specifically allow detached ADUs for multi-generational living, but approval is never automatic and exterior materials usually need architectural review committee sign-off. We prepare the HOA submittal package for you: elevations, finish schedules, and lot placement drawings that give the committee what it needs to approve without resubmission. Call (210) 981-6358 to start that paperwork early.
Yes, most Selma slab-on-grade homes built after 2000 can carry a partial second story, but it requires a structural assessment of the existing slab and framing plus steel columns and pier supports at the new load path. Our licensed structural engineers design the tie-in so the second story doesn’t transmit movement into the first-floor walls. We’ll tell you early if your specific house needs deeper footings, and we’ll price that work in writing before we start.
We coordinate directly with your architect and designer from the first site walk; we handle the structural and HOA constraints, they handle the vision, and we manage the long-lead material orders so the custom pieces arrive when the framing is ready. Our job is to make their drawings buildable on your specific Selma lot and to keep the budget fixed while they refine finishes. Bring us in early, before drawings are complete, and we’ll flag foundation and HOA issues while they’re still cheap to fix on paper.
Planning an addition in Selma? Call (210) 981-6358 for a free estimate. We’ll walk your lot, talk about your soil, your HOA, and your long-lead materials, and give you a written price before anything gets ordered.
Written by Ben Ortega, Owner at Seedling ADU San Antonio, serving Selma homeowners with written pricing and the 365-Day Done Right Promise.









