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 Southlake
Home additions and ADU construction in Southlake typically runs $45,000 to $130,000 for a room addition, and $90,000 to $220,000 for a detached ADU, with garage conversions landing between $30,000 and $80,000. Before you sign anything, you should know which Southlake-specific code layers a compliant quote has to include: tree preservation permits, clay-soil foundation engineering, HOA architectural review, and wind-load documentation. Miss any one of those, and a project that starts clean can end in a stop-work order. You can reach us at (877) 610-1318 to talk through what your specific property will require.
Why Barrett & Sons Construction Is Southlake’s Preferred Home Additions & ADU Company
Barrett & Sons Construction has been owner-operated since 1998, and Tom Barrett’s sons run the crews that work in Southlake. That matters in a city where the homes are large-footprint custom builds, not production-line boxes. We are the Home Additions & ADU team that shows up with a written scope, a written allowance sheet, and a face you’ll recognize at the hardware store. Our customers in Southlake know Tom publishes his name, address, and license number, so you can verify us before you sign anything.
We’ve worked inside Timarron, Carillon, and the custom-home streets off Southlake Boulevard long enough to know what the HOAs will reject before they see it. Our crews carry premium material lines for every trade, and every eligible job gets permits pulled and inspections signed. That’s not a sales pitch; that’s the only way we’ll leave a job in Southlake. The 90-Day Done Right Promise is written on every contract. One call brings Tom back.
Response time to Southlake is tight. We coordinate schedules from our DFW office, but the crews who work your job are local, and a live person answers our phones around the clock at (877) 610-1318. You will not reach a voicemail box or an out-of-state call center.
Our Home Additions & ADU Services in Southlake
ADU Design & Permitting
Before we pour concrete or set a single stud, we handle the Southlake tree preservation permit. That’s the layer that blindsides contractors from two cities over. If a protected live oak sits where your detached ADU needs to go, the city requires a mitigation or replacement plan before removal, and that can add two to four weeks to site prep. We build that timeline into your written schedule from day one.
New Detached ADU
A new detached ADU in Southlake runs $90,000 to $220,000, and the slab is the part you should worry about first. We sit on expansive Blackland Prairie clay. It swells in wet seasons and shrinks in dry ones, and a slab poured without accounting for that movement cracks within years. We work with local geotechnical and structural engineers who know Southlake soil, not a generic spec out of a handbook.
Garage Conversion ADU
Converting a garage in Southlake is often the fastest path to rental or in-law space, but it’s not a drywall-and-paint job. The existing slab may not meet current foundation codes for habitable square footage, and the structure has to meet wind-load criteria before an inspector will sign off. Our quotes include the structural drawings, the permit fees, and the HOA package, all in writing. Typical range: $30,000 to $80,000.
Junior ADU & Interior Conversion
For homes with a big bonus room or an oversized study, a junior ADU can add a private entrance, a kitchenette, and a full bath without changing the footprint. In Southlake, that still means permits and inspections. We pull them. You should ask any bidder who says otherwise how they plan to handle the final inspection when the owner’s agent asks for the sign-off.
What happens when you call
- 1
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 Southlake
We stock and install material lines that Southlake homes expect: Techo-Bloc and Cambridge Pavers for hardscape tied to your addition, and structural engineered components built to more than code-minimum North Texas wind ratings. If a spec calls for matching existing luxury finishes like natural stone or brick, we’ll document the compatibility in the written scope before work begins. No mystery brands off a van. You can look up everything we install, just like you can look up our license.
Common Home Additions & ADU Problems We See in Southlake Homes
- Skipping the tree preservation permit before site prep. In Southlake, a protected tree on a private lot requires a city permit and a mitigation plan before removal. A contractor who skips this step gets a stop-work order, and the homeowner is the one who eats the delay.
- Pouring a foundation slab without clay-soil engineering. Blackland Prairie clay expands and contracts with DFW’s wet-dry cycles. A slab that doesn’t account for it starts hairline-cracking within a few years, and a second-story addition on top makes it worse.
- Filing an incomplete HOA package in communities like Timarron or Carillon. Southlake HOAs reject materials, colors, and designs that would pass next door in Keller. You need samples and renderings matched to the home’s existing luxury finishes, submitted before the first nail moves.
- Not documenting wind-load compliance for insurance. North Texas storm codes require wind-load ratings on structural work. An inspector’s sign-off with documented structural review is the proof you’ll want if a storm damages the addition later. A low bid that leaves that out isn’t cheaper; it’s uninsured.
Pricing for Home Additions & ADU in Southlake, TX
Here’s what you’ll see in the Southlake market:
| Project Type | Southlake Price Range |
|---|---|
| ADU Construction | $90,000 - $220,000 |
| Home Addition | $45,000 - $130,000 |
| Garage Conversion | $30,000 - $80,000 |
What moves your price? Tree removal and mitigation requirements, foundation engineering for clay soil, the complexity of matching an existing stone or hip-and-valley roofline, and whether the HOA requires material samples up front. A cheap bid leaves line items out and hopes you won’t notice. Our quotes include notes for every one of those layers, in writing, before you sign. Call (877) 610-1318 for a free estimate on your specific project.
We Also Serve Cities Near Southlake
Our crews work throughout the Southlake area and the surrounding communities of Colleyville, Grapevine, Roanoke, and Trophy Club. If you live just outside Southlake, the same owner-operated team, the same written change orders, and the same 90-Day Done Right Promise apply. You can reach us at (877) 610-1318 wherever you are in the county.
Serving Southlake, TX - Our Local Coverage Area
We’re based in the Southlake 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 Southlake
Yes. Southlake enforces wind-load criteria for structural work on additions and ADUs, and your final inspection sign-off should document the structural review. Keep that paperwork with your insurance file. Call (877) 610-1318 and we’ll walk you through what a compliant quote includes, free.
It can add two to four weeks if a protected tree on your lot has to come down for the ADU site. Southlake requires a permit and a mitigation or replacement plan before removal, and we build that into the written schedule on day one. Get the permit before the shovel, or the stop-work order finds you.
It should include the tree preservation permit scope, foundation engineering for Blackland Prairie clay, wind-load-rated structural drawings, HOA package preparation if you’re in a community like Timarron or Carillon, and a documented inspection sign-off for your insurance file. A bid without those line items is a surprise invoice waiting for a date. Call (877) 610-1318 for a written estimate that shows them all.
Yes. Most Southlake communities with architectural review boards require materials, colors, and design submitted for approval before construction starts, and they can reject a proposal that doesn’t match the existing luxury finishes. We prepare that package for you, samples included, before work begins.
No. A garage conversion in Southlake changes the use of the space to habitable square footage, and that triggers structural review, wind-load verification, and updated drawings with the city. Skipping that leaves you with an unpermitted living space that an appraiser and an insurance adjuster will both flag. Call (877) 610-1318, and we’ll explain the exact permit path for your lot.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Southlake, TX since 1998.