Frequently Asked Questions - ADU in San Antonio, TX
Straight answers on ADU costs, timelines, permits, and what it's actually like to build one in San Antonio. If your question isn't here, call (430) 258-2928 and we'll get you an answer along with a free written estimate.
Pricing & Cost FAQs
An attached or detached ADU in San Antonio typically runs $180 to $320 per square foot, so a 600-square-foot unit usually lands between $110,000 and $190,000. Your final number depends on foundation type, utility connections, finish level, and whether you're converting a garage or building from scratch. In neighborhoods like Alamo Heights and Terrell Hills, steeper slopes and mature trees can add site-prep costs that a flat lot in Live Oak wouldn't have. We put every price in writing before work starts, so there are no surprises once framing begins. Call (430) 258-2928 for a free estimate specific to your lot.
A garage conversion in San Antonio usually costs $80,000 to $140,000 depending on the condition of the slab, existing electrical, and plumbing tie-ins. Older homes in Castle Hills and Windcrest sometimes need panel upgrades, which adds to the total. The foundation is often already there, which keeps costs below a full ground-up build. We inspect the existing structure and give you a written line-item price before any work starts. Call (430) 258-2928 to get your exact number.
A garage conversion is generally the least expensive path because the shell, roof, and slab already exist. The next tier is a prefab or modular unit, where factory construction keeps framing waste down. Full custom detached construction costs the most because everything, from foundation to roof, is built on your site. In Schertz and Converse, where lots tend to be bigger, a detached prefab unit can be a strong value. We'll walk you through side-by-side pricing for each option so you can compare actual numbers, not vague ranges.
Yes, building an ADU increases your property's assessed value in Bexar County, which raises your property tax bill. The Bexar Appraisal District will reassess your home after the permit is closed and the structure is on the appraisal roll. That said, most San Antonio homeowners find the rental income from the ADU more than offsets the tax increase. We recommend talking to a local tax advisor before you commit. We'll give you the construction numbers; your accountant can give you the tax picture.
ADUs in San Antonio generally appraise for 60 to 80 cents on the dollar of construction cost, and monthly rental income in desirable pockets like Alamo Heights or near Lackland AFB often ranges from $900 to $1,400 for a one-bedroom. That makes the payback period attractive for many owners, especially with steady military and medical-center rental demand. The key is building at a square-foot cost that matches your neighborhood rents. We'll help you price both sides before you commit. Call (430) 258-2928 to talk numbers.
Adding a full bathroom and kitchenette inside an ADU typically accounts for $35,000 to $60,000 of the total build, driven by plumbing rough-ins, fixtures, cabinetry, and countertops. In older San Antonio neighborhoods, cast-iron waste lines sometimes need replacement, adding cost. We recommend budgeting for PEX supply lines and a dedicated water heater for the unit. Written pricing covers every fixture and finish before we order materials, so you know exactly what each upgrade costs.
We don't offer in-house financing, but we're glad to supply a detailed written estimate that most banks, credit unions, and HELOC lenders in San Antonio will accept for a construction loan application. Many local owners use a home equity line against their existing mortgage. The estimate breaks down every phase so your lender sees exactly where the money goes. Call (430) 258-2928 and we'll get that document to you fast.
Service & Process FAQs
The ADU process with our team starts with a free site visit and written scope, then moves through design, city permit submittal, foundation and utility work, framing, mechanicals, finishes, and final inspection. Every step has a documented price before we start it. You'll get photo updates of the work as it progresses and a live arrival time when our crew is headed your way. The city of San Antonio requires a building permit for any ADU, and we handle that paperwork for you. Expect the full process to run roughly four to seven months depending on scope.
You need a building permit from the City of San Antonio Development Services Department, and depending on your lot, a zoning verification and possibly a tree or drainage review. If your property has a homeowners association, in places like Terrell Hills or Windcrest, HOA approval is a separate step you'll want to start early. Our team pulls every permit, coordinates inspections, and walks you through anything the city flags. We don't start construction on an unpermitted ADU, and we recommend you never hire a builder who suggests skipping permits.
A garage conversion typically finishes in three to five months. A ground-up detached ADU usually takes five to seven months from first permit submittal to final inspection. San Antonio's permitting review times move at their own pace, and weather delays, especially during spring rains, can shift the schedule. We keep you updated with photos at every milestone so you're never wondering what's happening on your own lot. Call (430) 258-2928 and we'll give you a realistic timeline for your specific project.
It depends on your HOA's covenants. Some HOAs in San Antonio, including several in Alamo Heights and Terrell Hills, restrict ADUs entirely or cap their size. Others require design review before you even apply for a city permit. We'll help you read your HOA documents and figure out what's possible before you spend anything. In most cases, we recommend getting written HOA approval first, then submitting city permits, so you don't pay for plans that get rejected. Call (430) 258-2928 and we'll walk through it together.
We handle the design in-house, including the drawings needed for permit submittal in San Antonio. Most ADUs don't require a separate architect unless you're doing something structurally unusual, like building on a steep hillside lot in Bulverde or adding a second story. Our design process focuses on practical layouts, efficient plumbing stacks, and natural light. You'll see the plan and the price before anything is built. Call (430) 258-2928 to talk about what you're imagining for your space.
Yes, you can absolutely include a full kitchen in your San Antonio ADU. Most homeowners building a rental unit want a kitchenette at minimum, and a full kitchen is common in detached units built for long-term tenants. The city treats an ADU with a kitchen as a separate dwelling unit, so it triggers its own utility metering considerations. We'll design the kitchen around your budget and use every square foot efficiently. Written pricing covers the cabinetry, counters, and appliances you select.
San Antonio ADUs typically tie into the main house's water and sewer service through a new branch line, while electricity can be a subpanel off the main panel or a separate meter depending on whether you plan to rent the unit. CPS Energy and SAWS have specific requirements for secondary dwelling units, and we coordinate with both utilities during the build. If your existing panel doesn't have spare capacity, which we see often in older Kirby and Leon Valley homes, a panel upgrade will be part of the written scope. We'll explain every connection in plain English before work starts.
Brands & Parts FAQs
Yes, we can install a prefab ADU from manufacturers like Boxabl or Plant Prefab on a properly prepared San Antonio lot. Prefab units require the same foundation, utility stubs, and permits as site-built units, but the module itself arrives mostly finished. The tradeoff is lead time; factory production slots fill up, so you'll want to plan ahead. Our team handles the site work and finish connections, and we'll give you a written price that includes the module, delivery, and installation. Call (430) 258-2928 to compare prefab and stick-built numbers.
We build with durable, low-maintenance materials suited to the San Antonio climate: engineered siding, metal roofing, and fiber cement products like James Hardie. The sun and humidity here demand materials that won't warp, fade, or attract termites. We also detail flashing and ventilation carefully, because our hot, humid summers are harder on a small structure than people expect. A Tuff Shed might work for storage, but a conditioned living space needs real building science behind it. We'll show you material samples and prices before you choose.
We don't recommend converting a Tuff Shed into habitable space in San Antonio. Tuff Sheds are built as storage structures, not living spaces, and bringing one up to city residential code requires replacing or reinforcing nearly everything: framing, insulation, electrical, plumbing, and foundation. By the time you're done, you've spent close to what a purpose-built ADU would cost, and the result is still a compromise. If you want a shed-style aesthetic, we can design a small unit with that look that actually meets code. Call (430) 258-2928 and we'll show you the comparison.
Licensing & Insurance FAQs
Every pro working under the Benson ADU name is required to hold the license and insurance their state and trade require. We carry the coverage our clients expect, and we're glad to provide proof of insurance before any project starts. The City of San Antonio permiting process also verifies contractor credentials as part of the application. We're fully transparent about who's on your property and what coverage applies. Call (430) 258-2928 and we'll send over our documentation.
Troy Eastman leads our San Antonio team. Troy is the person you'll meet at your first site visit, and he's the one accountable for your project from first sketch to final inspection. He's built the local crew around the same visible-pricing and photo-update standards the Benson brand is known for. When you call (430) 258-2928, our live coordinator gets you connected with Troy and the local team fast. No phone tag, no runaround.
Emergency & Response FAQs
Yes, we can assess and repair ADU storm damage or leaks in San Antonio, and we'll get you a written repair price before any work starts. We're available Monday through Friday from 7:00 AM to 7:00 PM and Sunday from 7:00 AM to 7:00 PM. If your unit has active water intrusion, document what you can, shut off power to affected areas if it's safe, and call (430) 258-2928 during our hours. We'll schedule a visit and send you photo updates of the repair as it happens.
While you're waiting for repair, contain the water with buckets or a tarp if you can reach the area safely. Move electronics and furniture away from the leak and shut off power to the affected room at the breaker panel if water is near outlets or fixtures. Roof work is dangerous, and we don't recommend climbing onto a wet or steep roof yourself. Call (430) 258-2928 and we'll get you on the schedule with a written price before we touch anything.
Warranty & Guarantees FAQs
Yes, every Benson ADU project is covered by The Relay Visibility Guarantee, which gives you a live arrival time, photo updates of the work before and after, and a written price before anything starts. On top of that, we stand behind our workmanship with a workmanship warranty, and the exact term and coverage is written into your contract before you sign. You'll know exactly what's covered, for how long, and how to reach us if something needs attention. That's the standard we work to.
No, the price you approve in writing is the price you pay unless you ask us to change the scope. If something unexpected comes up during construction, like hidden damage behind an old garage wall in Castle Hills, we stop, document it with photos, and give you a written change order before doing anything else. You approve the change or you don't; nothing happens without your sign-off. That's the Relay Standard: the price is in writing before work starts, and it stays that way.
If something isn't right after your ADU is finished, call us and we'll send someone back to look at it. Every project is covered by a workmanship warranty with the terms spelled out in your contract. Plus, the photo documentation from our build process means there's a record of every phase, making it easy to pinpoint what needs attention. We want the phone call. We'd rather fix something quickly than leave you with a problem that erodes trust. Call (430) 258-2928 and we'll take care of it.
If your existing ADU in San Antonio needs work and the original builder is out of the picture, we can assess the issue and give you a written repair price. We can't honor another company's warranty, but we can absolutely fix the problem, permit the repair if needed, and stand behind our own work going forward. Most repair jobs on existing ADUs are straightforward: drywall, flooring, roof leaks, or cabinet and fixture issues. Send us photos at (430) 258-2928 and we'll tell you what we're looking at.
Written by Troy Eastman, Owner at Benson ADU San Antonio, serving the San Antonio area with written pricing and visible progress since 2006.
Still Have Questions?
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(430) 258-2928