Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Garland
Adding square footage to a Garland home almost always means building on Blackland Prairie clay, and if your contractor doesn’t plan for that soil movement from day one, you’ll pay for it twice. A well-engineered room addition or ADU in Garland typically runs $45,000 to $130,000, with garage conversions and smaller additions landing at the lower end and new detached units reaching $90,000 to $220,000. Tom Barrett and his sons have poured, framed, and finished additions across Garland’s ZIP codes long enough to know exactly where the soil shifts, which mid-century floor plans flex, and what the city inspector will flag before he even gets out of his truck. We’re the local Home Additions & ADU crew that pulls every permit and puts every allowance in writing. Call (877) 610-1318 to schedule a free estimate.
Why Barrett & Sons Construction Is Garland’s Preferred Home Additions & ADU Company
Barrett & Sons was founded in 1998 by Tom Barrett, and Tom’s sons still run the crews. That matters in Garland, because the houses here aren’t interchangeable. The 1950s brick-veneer ranch on a quiet street off Belt Line Road has different bones than the 1980s tract home near Firewheel, and the guy who gives you a price over the phone without walking the slab isn’t quoting you a real number. We’re the Home Additions & ADU in Garland team that shows up, checks the foundation, reads the soil, and then puts a written scope in your hand. No allowances hiding in the margin. No change orders that appear after the drywall goes up.
When you call Barrett & Sons, a live person answers the phone, 24/7. You won’t get a voicemail box or an out-of-state call center. And because Tom publishes his name, address, and license number, you can verify exactly who you’re hiring before you sign anything. The 90-Day Done Right Promise is written on every contract: if it isn’t done right, one call brings Tom back to make it right. Ask anyone on your street, or look up the license number yourself.
Our Home Additions & ADU Services in Garland
Most Garland homeowners reach out to us unsure whether they should add on, convert, or build separate. We walk through all three options on-site, and we’re honest about which one makes sense for your lot, your foundation, and your budget. Here’s what we handle most often.
ADU Design & Permitting
Garland’s planning rules for accessory dwelling units have shifted over the years, and contractors who don’t keep up with current code end up with stop-work orders. We handle the full design and permitting package, from initial site survey through final inspection. The permit inspector works for you, not for me, and that’s exactly why I like him.

Garage Conversion ADU
Garland garage conversions typically run $30,000 to $80,000, depending on whether we’re working with an attached garage off a 1960s ranch or a detached structure with its own roofline. One thing we see often in the 75040, 75041, and 75042 corridors is prior unpermitted garage work, which means the inspector will require framing, electrical, and HVAC brought up to current code before any new space can close. We plan for that on the front end so the bid doesn’t balloon halfway through.

New Detached ADU
A new detached ADU in Garland commonly runs $90,000 to $220,000, and the single biggest cost driver is the foundation. Building on Vertisol clay means deeper piers, engineered slabs, and often soil moisture management systems that a builder who only works the sandy counties to the east never thinks about. We’ve poured enough slabs in Garland to know that skimping on pier depth here isn’t a shortcut; it’s a future lawsuit.

Junior ADU & Interior Conversion
For homeowners who want a compact rental unit or an aging parent suite without a separate building, a junior ADU converted from an existing bedroom or den often lands between $45,000 and $90,000. These projects work well in Garland’s mid-century ranch homes, where a former formal living room or oversized utility space offers the square footage needed. We also handle the plumbing and electrical upgrades that come with adding a kitchenette and bath to an interior space, and if you’re already reworking the main house, our Kitchen Remodeling in Garland and Bathroom Remodeling in Garland crews can fold that work into the same permit set.

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 Garland
We run premium materials on every Garland job because mid-century framing and Texas clay demand better than off-brand product. You’ll see GAF roofing membrane on our ADU builds, Schluter waterproofing systems in wet areas, and Grohe fixtures in kitchens and baths. These are brands you can look up, not mystery product off a van. If a warranty issue ever comes up, Tom’s crew handles it directly, and we keep local stock for the common repairs Garland homes need.
Common Home Additions & ADU Problems We See in Garland Homes
- Slab heave at the new-to-old transition. The 1950s slab you’re tying into has been moving for 70 years, and the new addition moves differently. We design expansion joints and use pier depths that account for the Vertisol clay’s seasonal shrink-swell cycle under the Blackland Prairie.
- Unpermitted prior work discovered at inspection. Homes west of Jupiter Road in the 75040 and 75042 ZIPs often carry multiple decades of unpermitted room additions and garage conversions. When the inspector opens the wall, the unpermitted framing and electrical have to come up to current Garland code before anything new can pass.
- Inadequate wall insulation in mid-century construction. Winter Storm Uri exposed how thin those 1950s and 1960s walls really are. When we open a wall for an addition, we regularly find empty cavities or settled batt insulation, and we recommend upgrading the connecting wall’s thermal envelope while it’s exposed.
- Undersized electrical panels from the original build. A 100-amp panel from 1962 can’t run a new ADU kitchen and HVAC. We almost always include a panel upgrade in the scope when we add significant square footage to a Garland ranch.
Pricing for Home Additions & ADU in Garland, TX
In Garland, a room addition runs $45,000 to $130,000. A garage conversion ADU lands between $30,000 and $80,000. A new detached ADU runs $90,000 to $220,000. What moves the number is foundation work on expansive clay, the condition of the existing framing you’re tying into, and whether current code requires upgrades to the original home’s electrical or plumbing. Here’s the part that matters: every scope, every allowance, every price change arrives as a written change order before work happens. An allowance that isn’t on paper is a surprise waiting for a date. Call (877) 610-1318 for a free estimate with line-item pricing.
We Also Serve Cities Near Garland
Alongside our Garland work, we serve Sachse, Rowlett, Richardson, and Murphy from the same Barrett & Sons crews. If you live in one of those cities and you’re weighing a home addition, a garage conversion, or a full ADU, you’ll get the same owner-operated crew, the same written change orders, and the same 90-Day Done Right Promise. Call (877) 610-1318 to schedule a walkthrough.
Serving Garland, TX - Our Local Coverage Area
We’re based in the Garland 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 Garland
A home addition in Garland typically costs $45,000 to $130,000, depending on square footage, foundation requirements on the clay soil, and the condition of the existing structure you’re tying into. Garland pricing runs slightly above older suburbs to the west because most projects here involve mid-century slabs that need careful pier and joint design. Call (877) 610-1318 for an exact quote; our estimates are free.
Yes. Every eligible ADU and home addition project includes permits pulled and inspections signed. Garland’s current building code requires any new habitable space to pass structural, electrical, plumbing, and energy inspections, and we don’t cut corners on any of them. The permit inspector works for you, not for me.
Because our dispatch and scheduling are coordinated from the Dallas-Fort Worth office and our crews serve Garland locally, most estimates happen within a few days of your call, and a live person answers the phone around the clock. For emergency structural questions or an urgent addition-related issue, call (877) 610-1318 and Tom’s team will get you on the schedule fast.
Only if you approve a written change order first. If we open a wall in a 1962 ranch and find unpermitted wiring or rotted framing the inspector won’t pass, we’ll bring you a written change order with exact pricing before any extra work proceeds. Nothing gets added to your bill without your signature. That’s the only way we’ve run Barrett & Sons since 1998.
Yes. Every completed project is backed by our 90-Day Done Right Promise, written on the contract. If something isn’t done right, one call brings Tom back to make it right. We also honor the manufacturer warranties on every premium brand we install, including GAF, Schluter, and Grohe products used on Garland jobs.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Garland since 1998.







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