







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Terrell Hills, TX
Seedling ADU Builders helps Terrell Hills homeowners add accessory dwelling units, convert aging detached garages into rentable casitas, and expand their homes without disrupting the streetscape this city works so hard to protect. Terrell Hills is different from most of San Antonio: our crews navigate a separate set of zoning and design standards here, and the homes themselves, mostly 1920s to 1950s estate-style builds on oversized lots, require a careful hand. If you’re weighing an ADU or conversion in Terrell Hills, call (210) 981-6358 for a free estimate and a written price before anything begins.
Why Terrell Hills Homes Are Different

Terrell Hills has its own building codes and zoning, distinct from surrounding San Antonio. The city’s regulations were written to preserve the early-20th-century estate character, which means ADU work here often involves stricter setback requirements, lot coverage limits, and design review than in nearby municipalities. A detached garage or servant quarters built in 1940 can’t simply be converted without checking how the original structure sits on the lot relative to today’s rules.
The older homes also bring practical challenges. Many original detached garages in Terrell Hills have outdated electrical panels that can’t carry a modern mini-split and kitchen appliances without a service upgrade. The clay soil under much of the city expands and contracts with moisture, so any foundation work on a conversion or new ADU slab needs extra attention to drainage and compaction. And the mature oak and pecan trees that give Terrell Hills its character also determine shading, cooling loads, and where a prefab module can physically be set. We plan around all of it before crews arrive.
Our Main Terrell Hills Services
Most Terrell Hills calls to our team are about one of two projects: converting a historic detached garage into a livable unit, or adding a custom ADU or home addition while respecting the city’s design standards. Here is how each works in Terrell Hills.
Home Addition Contractor in Terrell Hills
Home additions in Terrell Hills almost always involve working against an original 1940s or 1950s home, matching rooflines, exterior materials, and window proportions so the new wing doesn’t look stapled on. The city’s design review process can be exacting, and we prepare documentation that speaks the city’s language before submission. Foundation work on Terrell Hills clay soils usually means engineered piers or added drainage, and we quote that as part of the written price, not as a surprise after demolition starts. Home Addition Contractor in Terrell Hills covers the full process.

Garage Conversion Contractor in Terrell Hills
Many Terrell Hills homes have detached garages set far back on the lot, often original to the home and architecturally interesting. Converting one into an income-producing casita or a private guest suite means preserving the exterior look while completely rebuilding the interior: new electrical service, insulation, plumbing, and usually a new roof membrane. Because the city limits impervious cover, we often keep the existing footprint exactly where it is rather than expanding outward. Garage Conversion Contractor in Terrell Hills explains what your specific garage can become.

ADU Builders in Terrell Hills
New detached ADUs in Terrell Hills are built to fit the lot, not the other way around. We work with prefab manufacturers that allow precise module sizing, which matters when a backyard has mature oaks, a pool, or utility easements that limit where a unit can sit. Terrell Hills is one of the few San Antonio-area cities where a new ADU must often be reviewed for architectural compatibility, and we handle that review as part of the job. ADU Builders in Terrell Hills walks through the options.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Terrell Hills
We spec and install ADUs and materials from our brands, including Boxabl, Plant Prefab, Tuff Shed, and James Hardie siding. Turnaround depends on the model and site prep, but we give Terrell Hills families a realistic schedule in writing before any deposit changes hands.
Pricing for ADU Company in Terrell Hills, TX
| Service | Typical range in Terrell Hills |
|---|---|
| Detached ADU (prefab, turnkey) | $150,000 – $280,000 |
| Detached ADU (stick-built) | $200,000 – $350,000+ |
| Garage conversion to ADU | $95,000 – $160,000 |
| Garage conversion to livable space (no kitchen) | $70,000 – $110,000 |
| Home addition (primary suite, 400 sq ft) | $120,000 – $200,000 |
| Home addition (two-room bump-out) | $90,000 – $150,000 |
| Electrical service upgrade (100A to 200A) | $3,500 – $6,000 |
| Foundation repair / leveling (per project, common on older Terrell Hills garages) | $5,000 – $15,000 |
| Mini-split HVAC for ADU (single zone) | $6,000 – $12,000 |
| Site prep, drainage, and utility trenching | $8,000 – $25,000 |
Prices in Terrell Hills trend toward the upper end when the project involves a historic exterior that must be preserved, significant foundation work on shifting clay, or a lot where mature trees limit crane and equipment access. Whatever the number is, you receive it in writing before any work begins, and it does not change unless you change the scope.
Neighborhoods We Serve in Terrell Hills
We work throughout Terrell Hills, including the streets closest to the city’s commercial edge and the deeper estate lots that back up toward the old golf course and Salado Creek. Our crews coordinate with the city directly and typically schedule initial site visits within a few business days. Neighborhoods we regularly serve in Terrell Hills include:
- Terrell Hills central (north of Terrell Hills City Hall)
- Oversized estate lots along Elizabeth Road and Eldon Road
- Homes near the Terrell Hills / Alamo Heights boundary
- Lots bordering Salado Creek on the east side of the city
- The southern residential streets near Harry Wurzbach
Service Area – Cities Near Terrell Hills
While this page covers Terrell Hills specifically, our crews also serve homeowners across San Antonio, TX, New Braunfels, TX, Selma, TX, and Boerne, TX. Each city has its own permitting path, and we know which one applies before we quote.
Serving Terrell Hills, TX - Our Local Coverage Area
We’re based in the Terrell Hills 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 ADU Company in Terrell Hills

Yes. Terrell Hills has its own zoning and building codes, and most ADU, garage conversion, and addition projects require city permits, often including design review because of the city’s estate-character standards. We prepare and submit the application package for you, and the permit path is included in our written price. Call (210) 981-6358 to confirm what your specific project needs.
Most Terrell Hills ADU and garage conversion projects take 4 – 9 months from permit submission to final inspection. The range depends on the city’s design-review queue, weather windows for foundation work, and whether the existing structure needs electrical or structural upgrades. We give you a written schedule before work starts and update it honestly as the project moves.
Yes. Every Seedling ADU Builders crew in Terrell Hills operates under the Cedarwell Care Promise: shoe covers and drop cloths inside the home, pet-safe products where there is a choice, a photo of the clean-up before the crew leaves, and a live person available by phone 24/7. That is our standard on every project, not an add-on. Call (210) 981-6358 for a free estimate.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Terrell Hills Customers Say
"Junior ADU conversion inside the house. They were incredibly clean about it, plastic walls, floor protection, daily cleanup, all with a toddler in the home. Couldn't have asked for more care."
- Marcus Oyelaran"They converted our garage and were so mindful that we were living right there through it. Quiet hours respected, site swept, nothing left out where the kids play. Lovely work."
- Eugene Park"Garage conversion into a studio. They sealed off the work area so dust didn't get into the house, and cleaned up every day before leaving. Calm, careful team to have around."
- Darnell Hobbs





