Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Before
After
Before
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AfterFast, Reliable Home Additions & ADU Across Round Rock
If you’re living in Round Rock right now, there’s a good chance your house was built fast, sold fast, and never quite fit the way your family actually lives. Maybe the kitchen table sits in the hallway because there’s no breakfast nook. Maybe your mother-in-law is moving in and the guest room doubles as an office, a gym, and a storage unit. Maybe you’ve priced a newer house and realized that in Williamson County’s market, you’d be paying $150,000 more for the same square footage you already own. A home addition in Round Rock typically runs between $45,000 and $130,000, and a well-built ADU can add real, usable square footage without leaving the neighborhood you know. Barrett & Sons Construction has been building additions and ADUs the right way since 1998, and we’d rather show you how we work than sell you on a brochure. Call (877) 610-1318 and let’s talk about what your house can become.
Why Barrett & Sons Construction Is Round Rock’s Preferred Home Additions & ADU Company
Tom Barrett started this company in 1998, and he still answers his own phone. That’s not a marketing line. It’s a fact you can test by calling (877) 610-1318 right now. His name, his address, and his license number are published and verifiable. In a city like Round Rock, where most homes were built by high-volume tract builders within the past 30 years, you’ve probably already met a contractor who quoted one number on the phone and handed you a different bill at the door. Barrett & Sons doesn’t work that way. Every scope, every allowance, every price change arrives as a written change order before any work happens. An allowance that isn’t on paper is a surprise waiting for a date.
We serve Round Rock directly, which matters when you’re planning an addition or ADU. This city’s homes share specific failure patterns because they were built in the same era, often by the same builders, on the same Blackland Prairie clay. A company that drives in from Austin occasionally won’t recognize a negative drainage problem on a Forest Creek lot the way a local crew will. Our Home Additions & ADU team knows these neighborhoods and what the soil does to them. Dispatch and scheduling are coordinated from our Austin office, but the crews work in Round Rock consistently. The permit inspector works for you, not for us. That’s why we like him. We pull permits on every eligible job and get inspections signed, because the last contractor most folks used told them permits were optional.
Ask anyone on your street, or look up the license number yourself. We’ve been doing this long enough that our reputation in Round Rock is built on the jobs we finished, not the ads we ran.
Our Home Additions & ADU Services in Round Rock
ADU Design & Permitting
Round Rock has seen a steady rise in ADU interest as home prices in Teravista and Forest Creek climb faster than most homeowners’ comfort levels. Whether you’re adding a rental unit or a long-term spot for aging parents, we handle the design work and pull the permits so you don’t sit in limbo with the city. ADU construction in the Round Rock area typically costs between $90,000 and $220,000. The range is wide because it depends on whether you’re converting existing space or building new from the slab up. But here’s the thing: a detached ADU on expansive clay soil needs a foundation designed for movement, not just a standard pour. We engineer for that.
Garage Conversion ADU
Garage conversions in Round Rock make particular sense in the 78664 and 78665 ZIP codes, where many homes from the early 2000s have oversized two-car garages that are used for storage anyway. A garage conversion in this market typically runs $30,000 to $80,000. The catch: these garages were rarely framed or insulated with living space in mind, and the concrete slab was poured without the vapor barriers you’d want under living space. We fix that as part of the scope, in writing, before the work starts. If you’re also weighing a Kitchen Remodeling in Round Rock project alongside the conversion, we can sequence the work so you’re not living in a construction zone twice. Or combine the ADU conversion with a Bathroom Remodeling in Round Rock to give the new unit a functional bath from day one.
New Detached ADU
A new detached ADU in Round Rock needs a foundation that holds up to Williamson County’s montmorillonite clay, which expands aggressively during wet seasons and shrinks sharply in droughts. This is not a theoretical concern. We see slab movement on existing homes all over the east-side subdivisions. A new detached ADU priced from $90,000 to $220,000 includes proper site grading, drainage correction, and a foundation engineered for the soil we’re actually building on. We don’t pour a generic slab and hope.
Junior ADU & Interior Conversion
If you have an unused formal dining room, a bonus room over the garage, or a walk-out basement space, a junior ADU might be the most cost-efficient path to extra living space. Interior conversions in Round Rock often run lower than new construction because framing and roofing already exist. But the existing house may have been built with builder-grade shortcuts in the 90s and early 2000s: undersized lintels, thin stucco detailing, and drainage grades that pitch toward the foundation. We identify those issues before we build on top of them. Converting interior space into a junior ADU often pairs naturally with a larger Round Rock addition when the family is growing and the house isn’t.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Round Rock
When we pour concrete for a new addition, lay pavers for the connecting patio, or run drainage lines around a new ADU foundation, we use materials you can look up by name. Belgard and Techo-Bloc for hardscape surfaces that hold up under Round Rock’s summer heat. Quikrete and Oldcastle products for concrete that’s mixed to spec for our clay soil conditions. We don’t stock mystery brands off the back of a van. For Round Rock customers, that means the materials we install have warranties you can actually enforce, and we know how they perform in this climate because we’ve been installing them here for decades.
Common Home Additions & ADU Problems We See in Round Rock Homes
- Negative drainage toward the foundation. In the east-side subdivisions built on former Williamson County farmland, original builder grading often left lots pitched toward the slab. After 15 to 20 years of clay-soil cycling, we regularly find that what the homeowner calls an addition actually requires regrading the perimeter and extending downspout drainage before any structural work can hold. That’s a site-prep cost most people never see coming.
- Slab movement from Blackland Prairie clay. Round Rock sits on the transition zone where heavy montmorillonite clay swells and shrinks with every wet season and drought cycle. That movement cracks flatwork, distorts door frames, and undermines any concrete work not engineered for the soil. We factor this into every addition and ADU foundation we design here.
- Builder-grade framing shortcuts from the boom years. Because the dominant housing stock in Round Rock was produced at volume between roughly 1995 and 2015, we see the same issues repeated across hundreds of nearly identical homes in Forest Creek, Teravista, and Stone Canyon. Undersized headers, minimal sheathing, and thin stucco detailing all show up when we open walls for an addition.
- Missing permits from prior work. More Round Rock homeowners than you’d expect discover that a previous owner added a room, a porch, or a garage conversion without permits. That creates real problems when you try to finance, insure, or sell the house later. We fix that by pulling permits for every new job and bringing unpermitted prior work into the inspection process where possible.
Pricing for Home Additions & ADU in Round Rock, TX
Here are straight numbers for the Round Rock market, based on what we’ve actually built in these ZIP codes. A standard room addition runs $45,000 to $130,000. A garage conversion ADU runs $30,000 to $80,000. A new detached ADU runs $90,000 to $220,000. These are not national averages. They’re calibrated for Round Rock’s labor market, material costs, and permit fees. What moves the number: foundation work on clay soil, drainage correction, sewer and utility tie-ins, and whether the existing framing can carry a second story. Summer temperatures topping 100°F compress concrete pour windows and accelerate moisture loss in framing lumber, which is why we schedule heavier structural work for favorable weeks. You’ll get a written line-item quote before we start, and if the scope changes, you’ll get a written change order before the change happens. Call (877) 610-1318 for your free estimate.
We Also Serve Cities Near Round Rock
If you’re just outside the Round Rock city limits, we regularly work in Hutto, Georgetown, Brushy Creek, and Pflugerville. The same clay soil issues, the same tract-home era, the same need for permits pulled and prices in writing. Home Additions & ADU in Round Rock is our primary market, but we know the surrounding cities well because the building stock is nearly identical and so are the problems.
Serving Round Rock, TX - Our Local Coverage Area
We’re based in the Round Rock 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 - Home Additions & ADU in Round Rock
We schedule initial consultations in Round Rock within a few business days, but for urgent structural concerns, we can usually get a crew member out sooner. Call (877) 610-1318 and our live phone person will get you on the schedule.
Yes. We work in Forest Creek, Teravista, Stone Canyon, and the east-side subdivisions across 78664, 78665, 78682, and 78683. If you’re unsure whether we cover your street, call us and ask directly. You’ll reach a person, not a voicemail box.
We don’t offer same-day emergency construction for planned additions. But if a failing foundation, a sagging beam, or a code violation is threatening your existing structure, call (877) 610-1318 and we’ll get someone out to assess it quickly. Safety issues don’t wait for a permit cycle.
Round Rock’s labor and material costs track close to Georgetown and Pflugerville, typically within a few thousand dollars on most projects. The bigger variable is soil condition and drainage, which can add $5,000 to $15,000 in site preparation on lots with known clay movement. We’ll show you exactly where your money goes in the written quote.
Every job comes with the 90-Day Done Right Promise, written on the contract. If something’s not done right, one call brings Tom back to make it right. That’s not a seasonal promotion. It’s how we’ve operated since 1998.
Call (877) 610-1318 to schedule your free estimate. Tom Barrett and his sons will walk the site with you, talk through what’s possible on your lot, and give you a written scope before you sign anything.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Round Rock and surrounding Central Texas communities since 1998.