Fast, Reliable Garage Conversion ADU Across Southlake
A garage conversion ADU in Southlake typically runs $165,000-$310,000 all-in, from permit set through final inspection, with high-end finishes on estate lots pushing past $375,000. Most projects take 5-8 months, and the single biggest variable isn’t labor. It’s the lead time on custom millwork, architectural glass, and specialty fixtures. If you’re weighing a detached garage conversion in Timarron or a partition-and-bath addition in Stone Lakes, call Ellery ADU Studio at (971) 497-2402. We’ll walk you through numbers that hold up.
We work across Southlake regularly, and we know what this city’s homes actually require. These aren’t starter homes. They’re 3,500 to 7,000 square feet, built to a high spec, and the finishes your neighbors expect don’t come off a shelf at a big-box store. Our Garage Conversion ADU team coordinates everything under one contract, so the designer and the builder answer to the same written scope.
Why Ellery ADU Studio Is Southlake’s Preferred Garage Conversion ADU Company
Southlake homeowners tend to research before they call, and they’ve usually already read the one-star reviews of other design-build firms. What we hear most from customers here is relief that the price was on paper before anything got ordered. That’s how we work. Every project is quoted with a written price before work begins, per Haven Standard Clause 1. No “call for a quote” runaround.
Nadia Ellery founded the studio in 2015, the same year California’s ADU permitting shift demonstrated what streamlined approvals could look like. That experience translates here. We’ve seen what happens when a Southlake permit gets issued and an HOA Architectural Control Committee hasn’t signed off. It stops the job. We prevent that by starting the HOA conversation in week one, not week ten. Over 900 ADUs designed, permitted, and built since 2015, every one with a written price and a documented photo record.
The crews serving Southlake are background-checked and uniformed, and our license number appears on every page we hand you. Scheduling is coordinated from our Dallas-Fort Worth office, so a live person answers the phone 24/7. That matters when a stop-work notice lands on a Friday afternoon.
Our Garage Conversion ADU Services in Southlake
Here’s where we focus in Southlake. These aren’t generic offerings. Each one is shaped by what this city’s lots, HOAs, and homes actually throw at a project.
Detached Garage Conversion
Detached three-car garages are common across Southlake, especially in Timarron and Stone Lakes, and they make excellent ADU candidates because the envelope already exists. What most owners don’t anticipate is the foundation work. North Texas black-clay soil heaves between wet winters and triple-digit summers, and an original garage slab that was never engineered for living space often needs underpinning or a post-tension replacement. We price that line item in writing, not as a change order later.
Garage Partition & Bathroom Add
Some Southlake owners don’t want to lose the whole garage. If you need space for an aging parent or an adult child but still want to park two cars, we can partition off a section, add a bathroom, and create a separate entrance. In subdivisions where the HOA limits full conversions, a partition sometimes falls under a different review path. We’ll check the CC&R language for your specific community before you spend a dollar on drawings.
Garage JADU
A Junior ADU carved from an attached garage can work on Southlake lots where a full detached unit would trigger setback variance reviews, the extra distance the city requires between your new living space and the property line. JADUs under a certain square footage often move through permitting faster. The catch is that a JADU still needs its own bathroom and kitchenette, and the plumbing runs on a slab are the hard part. We’ve done enough of these to know where the hidden costs live.
Attached Garage Conversion
Attached conversions in Southlake homes built roughly 1990-2015 tend to expose a different problem: bonus rooms. Many of these houses already have finished space above the garage, which means the structure is carrying more than a standard garage. Converting the bay below into living space requires a structural review of what’s stacked on top. We work directly with the structural engineer, and the report goes into your permit set, not a side folder.
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 Southlake
On high-end Southlake conversions, we regularly specify and coordinate prefab and modular systems from Cover, Dvele, and Mighty Buildings. These aren’t afterthoughts to us. When a client wants a panelized system for speed or a precision-built module for a detached ADU, we handle the manufacturer coordination inside the same single contract. That means the foundation tolerances, the utility stubs, and the finish tie-ins are all written down before the factory starts cutting. No finger-pointing between the builder and the module supplier when something’s off.
We also stock and specify the finish materials Southlake homes demand: custom cabinetry, European lift-and-slide doors, specialty plumbing fixtures. These are the items that actually set your completion date. If you wait until framing to order them, your four-month job becomes a nine-month job. We lock them in during the permit phase.
Common Garage Conversion ADU Problems We See in Southlake Homes
- City permit issued, HOA approval never obtained. Timarron’s CC&Rs from the early 1990s define “accessory structure” in language that predates modern ADU concepts. A city permit does not bind the HOA. We’ve seen jobs stopped mid-project by a violation notice after millwork and glass were already in production. We get Architectural Control Committee approval in writing before we order anything long-lead.
- Foundation quoted without accounting for black-clay heave. The expansive soils under Southlake shrink in dry summers and swell in wet winters. An existing garage slab that looks fine today may have hairline cracks that widen under live load. A detached ADU needs a properly engineered foundation, and that line item belongs in the written price from day one, not as a late discovery.
- Finish expectations priced as if this were a standard DFW suburb. A 5,000 square foot Southlake home sets a baseline for what an ADU on that property should look like. Custom cabinetry, architectural glass, stone counters. Regional labor rates don’t cover that. We price finishes against what the house itself already has, so you’re not $20,000 short when the cabinet quote lands.
- Bonus room above the garage overlooked in structural planning. Many Southlake homes built in the 2000s have finished space over the garage. Converting the bay below changes the load path. Skip the structural review and you’re gambling with an occupied room overhead. We include the engineer’s stamped report in the permit set every time.
Pricing for Garage Conversion ADU in Southlake, TX
Here are real ranges, not industry averages. An attached garage conversion in Southlake runs $145,000-$235,000. A detached garage conversion on an estate lot in Timarron or Stone Lakes runs $185,000-$310,000, and the higher end reflects post-tension foundation work and premium finishes. A garage partition with a bathroom add runs $90,000-$150,000. A garage JADU typically lands between $75,000 and $120,000. Every one of those numbers includes the permit set, construction, and a written scope with no change orders unless you request them. Call (971) 497-2402 for a written price on your specific property. Estimates are free, and we’ll give you a Free Second Opinion on any written estimate you already have in hand.
We Also Serve Cities Near Southlake
Our garage conversion ADU work extends beyond Southlake into Garage Conversion ADU in Southlake and the surrounding communities. We regularly serve Colleyville, Grapevine, Flower Mound, and Bedford, where the permitting and HOA landscape shifts in ways we know how to navigate. If you’re in one of those cities, the same written-price guarantee and one-contract model applies.
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 - Garage Conversion ADU in Southlake
Yes. The City of Southlake issues the building permit, and the Timarron HOA’s Architectural Control Committee has its own approval process that runs parallel to and independent of the city. The HOA’s early-1990s CC&Rs define “accessory structure” in language that doesn’t recognize modern ADUs, so what the city approves isn’t automatically what the HOA allows. Skipping the HOA step can get you a stop-work order mid-project. We handle both tracks from week one and get HOA approval in writing before ordering long-lead materials. Call (971) 497-2402 and we’ll review your specific CC&R language.
Expansive black-clay soils shrink during dry summers and swell during wet winters, which heaves unengineered slabs enough to crack drywall and bind doors. An existing garage slab built for parking isn’t designed for that movement under living space. We typically specify a post-tension slab or pier-and-beam foundation, and the engineer’s stamped report becomes part of your permit set. The cost is real, and it belongs in your written price before we start, not as a surprise on day forty. Call (971) 497-2402 for a number that includes the foundation work.
Yes, and it’s often the most cost-efficient path in Southlake because the framing, roof, and some electrical are already there. The limiting factors are egress, a separate entrance, and whether the existing structure was engineered for live load rather than storage. Many bonus rooms in Southlake homes built 1990-2015 were permitted as attics or storage, which means converting them to living space requires a structural upgrade and a new permit. We’ll tell you in the first week whether your bonus room can get there without a full garage rebuild. Call (971) 497-2402 to have us look at your plans.
Materials. Custom millwork, architectural glass doors, and specialty plumbing fixtures are long-lead items with 8-16 week factory timelines. If you don’t order them until framing starts, your project stalls while every downstream trade waits. Labor moves fast once materials are on site. We lock millwork, glass, and fixtures in writing during the permit phase, so the schedule is set before the first hammer swing. That’s how a Southlake conversion stays at five months instead of stretching to nine. Call (971) 497-2402 and we’ll show you a sample order timeline for your finish tier.
Stone Lakes’ deed restrictions are newer than Timarron’s and in some cases were drafted after ADU concepts entered the DFW planning conversation, which means the language can be less ambiguous about what constitutes an accessory dwelling unit. But Stone Lakes also tends to enforce lot-coverage ratios and setback buffers more strictly, so a detached conversion that works on a Timarron acre may need a variance in Stone Lakes. The HOA’s authority in both communities runs parallel to Southlake’s permit office. We review the specific CC&R language for your address before we draw a line. Call (971) 497-2402 for a Free Second Opinion on your property’s path.
Written by Nadia Ellery, Owner at Ellery ADU Studio. She has led the studio since 2015, and every project under her watch is governed by The Haven Standard: a written price before work starts, a documented photo record on every visit, and a 365-Day Done Right Promise in writing.