Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Georgetown
A home addition in Georgetown, TX typically runs $45,000 to $130,000, while a detached ADU lands between $90,000 and $220,000 depending on foundation conditions and finish level. The wildcard here isn’t the lumber package or the flooring, it’s what’s under the grass. Georgetown straddles the Balcones Escarpment, so the same square footage can cost two very different amounts depending on whether your lot sits on limestone ledge in 78628 or expansive clay in 78626. We’ve been building and remodeling in Williamson County long enough to know which one you’re likely dealing with before the first shovel goes in. Call (877) 610-1318 and we’ll walk your lot with you before quoting a number we’d have to change later.
Why Barrett & Sons Construction Is Georgetown’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998 and still answers his own phone. His sons run the crews. When we say someone named Barrett will be on your Georgetown job site, we mean it, most days it’s two of them. That’s the difference between us and a national outfit that sends a rotating cast of strangers to Wolf Ranch one week and Morningstar the next.
Georgetown homeowners have a specific kind of skepticism, and they’ve earned it. They’ve been burned by phone quotes that turned into door-knock surprises. Our contract works the opposite way. Every allowance, every scope change, every unexpected condition at your property goes onto a written change order before a single nail moves. The permit inspector works for you, not for me, that’s why we pull permits on every eligible job and get every inspection signed. You can look up Tom’s name, address, and license number before you sign anything. We’d rather you did.
We serve Georgetown for additions, ADUs, garage conversions, and second-story work from our Austin-area office, with crews on Georgetown jobs every week. A live person answers (877) 610-1318 around the clock, not a voicemail box. Ask anyone on your street, or look up the license number yourself.
Our Home Additions & ADU Services in Georgetown
ADU Design & Permitting
Georgetown’s ADU rules have tightened as the city has grown, and the review process at the Williamson County planning desk rewards complete submittals. We handle the drawings, engineering, and permit package as one scope. For a standard detached unit on a Georgetown lot, plan for permitting to add three to six months to your timeline before framing starts. We write that into the schedule up front so you’re not wondering where the crew went.
Garage Conversion ADU
Converting an existing garage is usually the least expensive way to add rentable or multigenerational square footage, and in Georgetown it runs $30,000 to $80,000 depending on whether the slab, electrical panel, and exterior walls can be reused. Many 1990s and early-2000s homes in 78633 and 78628 have garages that were never insulated or properly flashed at the slab edge. We find that on almost every conversion we do here. If the slab has moisture driven by Georgetown’s clay soils, we address it before drywall goes up, not after.
New Detached ADU
A new detached ADU in Georgetown is the project where local geology decides the budget. On the west side in 78628, excavation can hit limestone ledge at 18 to 24 inches, which means a rock-breaking line item that wouldn’t exist 15 miles east toward Round Rock. On the east side, the expansive clay heaves enough that we spec deeper piers and reinforced footers. Both conditions are predictable. We show you the allowance in writing before you sign, and we don’t bury it in the fine print.
Junior ADU & Interior Conversion
Junior ADUs and interior conversions, like turning a sitting room, oversized utility room, or underused dining area into a private suite with its own entrance and kitchenette, are the fastest path to an extra unit without the full foundation scope. In older Georgetown homes, the biggest variables are load paths and electrical capacity. Homes near the historic core around the Williamson County Courthouse often have original wiring that must be upgraded when we pull the permit. That’s a code requirement, and it protects you even when it stings the budget.
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 Georgetown
We don’t stock mystery brands off a van. When your Georgetown project calls for hardscape or exterior improvements around the new addition, we work with Techo-Bloc and Cambridge Pavers because they hold up to Central Texas heat and clay-soil movement better than cheaper alternatives. For concrete work around ADU slabs and walkways, we use Quikrete and Oldcastle products we’ve tested across hundreds of Williamson County jobs. Your Home Additions & ADU team will tell you exactly what’s going in and why before we order the first pallet.
Common Home Additions & ADU Problems We See in Georgetown Homes
- Limestone ledge in 78628. West-side Georgetown lots regularly hit caliche or solid limestone at 18 to 24 inches. A flat-prairie foundation bid from an out-of-town contractor will blow up the moment the excavator stops dead. We write a rock-breaking allowance into every west-side ADU and room addition quote.
- Failed waterproofing in 15-25-year-old Sun City homes. The Del Webb inventory in 78633 is entering its first major renovation cycle, and the original waterproofing at slab edges is failing on many homes. When we open walls for an addition, we find rot at the sill plate. That has to be repaired and inspected before rough-in can pass.
- Undersized framing for second-story additions. Many 1990s Del Webb and production homes in Georgetown were never engineered for vertical load. Adding a second story means verifying and often reinforcing the first-floor framing first. We do that inspection before we quote, not after we’ve opened the ceiling.
- Clay-soil foundation movement on the east side. Georgetown’s expansive Vertisol clay heaves and contracts through wet-dry cycles, and the result is slab movement. A new ADU foundation on east-side soil needs deeper piers than a builder from flatter ground would specify. It costs more up front and avoids cracks later.
Pricing for Home Additions & ADU in Georgetown, TX
Here’s what our bids typically reflect in the Georgetown market right now. These are real working numbers, not teaser ranges.
| Project Type | Typical Georgetown Range |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
What moves a Georgetown addition or ADU to the high end? Foundation conditions, first. Limestone ledge in 78628 adds excavation equipment and time. Expansive clay on the east side adds pier depth and concrete. Older homes in Sun City or near the historic downtown core trigger more code upgrades when walls come open, electrical panels get replaced, waterproofing gets repaired. We prefer to tell you that before demo starts. Call (877) 610-1318 to schedule your free estimate, and we’ll come walk the property, look at the soil, the slope, the existing framing, and the utility lines, then put a scope in writing with allowances for what we can’t see yet.
We Also Serve Cities Near Georgetown
Barrett & Sons Construction serves Georgetown and the surrounding communities, including Round Rock, Brushy Creek, Cedar Park, and Hutto. If you’re just outside Georgetown’s city limits, call (877) 610-1318 and ask whether we cover your street. We usually do.
Serving Georgetown, TX - Our Local Coverage Area
We’re based in the Georgetown 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 Georgetown
Yes, in most west-side Georgetown subdivisions the excavation runs into limestone ledge or caliche at 18 to 24 inches below grade. That adds a rock-breaking line item to your foundation scope. We write it into the contract as a defined allowance, and if the ledge turns out to be shallower than expected, you don’t pay for equipment we didn’t use. Call (877) 610-1318 to have us check your lot before you commit.
When walls come open on an older Georgetown home, the permit triggers current codes for electrical, smoke detection, insulation, and sometimes plumbing and structural ties. Homes built before the mid-2000s in Sun City and around the Williamson County Courthouse often need panel upgrades, arc-fault breakers, and new framing anchors. We show you those line items in writing before we start, not as a surprise at rough-in inspection.
We photograph the condition, show you the problem in person or by photo, and write a change order that describes the repair, the scope, and the price before we do the work. An allowance that isn’t on paper is a surprise waiting for a date. If we find rot at a slab edge or framing that won’t carry the new load, you approve the fix before anyone picks up a saw. Call (877) 610-1318 to talk through how our change-order process works.
Often yes, but first-floor framing in many 1990s Del Webb homes was not engineered for vertical additions. We bring in a structural engineer, verify the load path, and calculate what needs reinforcement at the foundation, posts, and beams before we quote the vertical scope. It adds an engineering step to the front end and protects you from a dangerous or failed addition.
Georgetown’s shrink-swell clay moves with every wet-dry cycle, and that motion cracks slabs that aren’t designed for it. On the east side of Georgetown, we typically specify deeper piers and reinforced footers for detached ADU foundations, sometimes with additional soil preparation. It costs more than a standard slab, and it’s cheaper than repairing a cracked foundation two years after the certificate of occupancy. Call (877) 610-1318 for an exact foundation quote based on your lot’s soil report.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Georgetown and Williamson County since 1998.