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 Carrollton
Adding onto a Carrollton home usually runs $45,000 to $130,000 for a room addition, while a full ADU construction project runs $90,000 to $220,000. The exact number depends on what’s behind your walls, under your slab, and whether you’re in south Carrollton’s 50-year-old 75006 stock or the newer northern ZIPs. We’re Barrett & Sons Construction, owner-operated since 1998, and we’ve opened enough Carrollton walls to know the difference. Call (877) 610-1318 for a free estimate, and we’ll walk your property before we write a single number.
Why Barrett & Sons Construction Is Carrollton’s Preferred Home Additions & ADU Company
Tom Barrett’s name is on the truck, and his sons run the crews. That matters in Carrollton, where a lot of homeowners have already been burned by a national outfit that quoted one price over the phone and showed up with another. We don’t work that way. Every scope item, every allowance, every price change arrives as a written change order before work happens. The permit inspector works for you, not for me, which is why we pull permits and get inspections signed on every eligible job. No exceptions.
Carrollton is a two-market town for construction. The southern half of the city, especially 75006, is dense with 1960s and 1970s slab-on-grade tract homes now past the 50-year mark, sitting on Blackland Prairie expansive clay that has spent decades heaving and cracking foundations. The northern ZIPs, 75007 and 75010, carry 1980s and 1990s brick-veneer subdivisions hitting their first full renovation cycle. A contractor who only knows one side of Carrollton will misread the other. We work both, often on jobs just a few miles apart.
Our Carrollton customers call a live person when they call us, 24 hours a day, seven days a week. Not a voicemail box, not an out-of-state call center. When you’re planning a $90,000 ADU or a $45,000 room addition, you deserve to talk to someone who knows exactly which ZIP you’re in and what that means for your slab.
Our Home Additions & ADU Services in Carrollton
ADU Design & Permitting
An ADU in Carrollton is a different animal depending on where you live. In Old Town Carrollton’s historic district, centered near Belt Line and Denton Drive, exterior materials and massing must clear architectural review before you even get to structural drawings. That’s a step neighboring cities like Farmers Branch or Addison don’t impose, and it catches out-of-area builders off guard, adding weeks. We’ve designed and permitted ADUs in Carrollton’s 75006, 75007, 75010, and 75011 ZIPs, and we know what the city’s reviewers look for before we submit. You’ll see the full permit path in writing before we file anything.
Garage Conversion ADU
Converting an attached garage into a living unit in Carrollton runs $30,000 to $80,000, depending on whether you’re working with a 1970s two-car garage in south Carrollton or a newer three-car in the Castle Hills area of 75010. The big variable is what’s under the slab. Many older Carrollton garages were poured thinner than living-space slabs and lack proper vapor barriers, which means we’re often cutting and repouring sections before framing begins. We write that into the allowance up front so the change order lands in your hand before a saw touches concrete.
New Detached ADU
A new detached ADU in Carrollton typically runs $90,000 to $220,000 and starts with a foundation engineered for Blackland Prairie clay. That’s the part a lot of builders skim. Carrollton’s expansive clay absorbs and releases moisture dramatically between North Texas droughts and storm seasons, and a foundation that isn’t designed for that movement will crack drywall within a year. Our Home Additions & ADU team specs post-tension slabs or pier systems based on soil tests, not guesswork. We also handle site prep, utility trenching, and tie-ins to the main house’s panel and plumbing.
Junior ADU & Interior Conversion
A junior ADU converts existing interior space, like a finished basement or oversized primary suite, into a self-contained unit with its own entrance and efficiency kitchen. In Carrollton’s older 1960s ranch homes, this often means reworking load-bearing walls and upgrading electrical panels that predate modern code. We’ve found Federal Pacific panels in south Carrollton homes that had to be replaced before rough-in could pass. That’s a real cost, and we put it in the allowance so it’s never a surprise at the end.
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 Install in Carrollton
We carry premium materials you can look up, not mystery brands off a van. For Carrollton additions and ADUs, we regularly install windows from Andersen and Marvin, roofing from GAF and CertainTeed, and hardscape work using Belgard and Techo-Bloc where patios or walkways tie into the addition. If your project includes a driveway approach or patio extension, we also work with Cambridge Pavers and Oldcastle products. Because we serve Carrollton locally, we can source these materials quickly and get them on site without the multi-week delays you see from builders working out of a regional depot. You’ll know the brand names before we order, and they’ll be written on your contract.
Common Home Additions & ADU Problems We See in Carrollton Homes
- Slab movement under south Carrollton additions. Homes in 75006 sit on expansive clay that’s been heaving for 50 years. Adding new square footage without first assessing the slab amplifies existing movement, and we’ve seen drywall crack within a year when builders skip the relevel. We assess first, frame second.
- Old Town Carrollton architectural review surprises. A modern exterior design on an ADU near Belt Line and Denton Drive will get bounced by the historic district, adding weeks. We design to preservation guidelines from the start, and we tell you what the review board will look at before you fall in love with a rendering.
- Code upgrades triggered once walls are open. Opening a 1960s Carrollton wall often reveals undersized framing, notched joists from old plumbing runs, or panels that don’t meet current code. A permit triggers upgrades, and we write those as allowances in your contract, priced in writing once we expose the condition, so the change order is never a surprise.
- Rough-in inspections closed too early. Burying electrical or plumbing behind new walls before Carrollton’s inspector signs off means you can’t prove the work met code without tearing it back open. We schedule inspections at the right points and get sign-off before sealing anything up.
Pricing for Home Additions & ADU in Carrollton, TX
Here’s what we tell Carrollton homeowners before we write a contract. A room addition runs $45,000 to $130,000. A full ADU construction project runs $90,000 to $220,000. A garage conversion runs $30,000 to $80,000. What moves the number? The age of your home, what’s under the slab, whether you’re in 75006’s older stock or 75010’s newer subdivisions, and what code upgrades your permit triggers once walls are open. We don’t hide those variables. We write allowances into the contract for the conditions we expect to find, and any surprise gets priced in a written change order before we touch it. Fixed pricing with no change orders is a promise made by people who haven’t opened your walls yet.
| Project Type | Carrollton Price Range |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
Call (877) 610-1318 to schedule a free estimate. We’ll walk your Carrollton property, look at what’s actually there, and give you a written line-item quote, not a phone number.
We Also Serve Cities Near Carrollton
Our crews work throughout Carrollton and the surrounding area, including Addison, Farmers Branch, Coppell, and The Colony. If you’re in a neighboring city and planning an addition or ADU, the same rules apply: written change orders, permits pulled, and the 90-Day Done Right Promise on every job. Call us and we’ll come out.
Serving Carrollton, TX - Our Local Coverage Area
We’re based in the Carrollton 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 Carrollton
The most common hidden conditions are slab movement from Blackland Prairie expansive clay, undersized or notched framing from decades of DIY plumbing runs, outdated electrical panels like Federal Pacific units, and failed waterproofing at the slab perimeter. On a 1960s ranch in the 75006 ZIP near Old Town Carrollton, we opened a load-bearing wall for a room addition and found undersized 2×4 framing notched to near failure, plus a Federal Pacific panel that had to be replaced before rough-in could pass inspection. We wrote the framing repair and panel upgrade into the contract as allowances, priced the change order in writing once the wall was exposed, and got inspection sign-off before sealing the subfloor. The addition is now rock-solid on a foundation we had to relevel after the slab had drifted 1.5 inches. Call (877) 610-1318 and we’ll assess your home before we quote.
Yes. Old Town Carrollton’s designated historic district, centered near Belt Line and Denton Drive, adds an architectural review layer that neighboring cities like Farmers Branch or Addison don’t impose. Exterior materials and massing must align with preservation guidelines, and that review happens before the normal building permit path. Out-of-area builders often design a modern exterior that gets bounced, adding weeks and forcing a redesign. We design to Carrollton’s preservation standards from the first drawing, and we’ll tell you what the review board looks for before you commit to a design. Call (877) 610-1318 to talk through your ADU plan.
Carrollton sits on Blackland Prairie expansive clay that absorbs and releases moisture dramatically between North Texas droughts and storm seasons, and that movement is the single biggest risk to any new foundation. A slab that isn’t engineered for that soil will heave and crack, and the new load of a second story amplifies existing differential movement, cracking drywall within a year. We spec post-tension slabs or pier systems based on soil tests on every Carrollton addition and ADU we build. Trying to add a second story onto a 1960s south Carrollton home without first releveling the slab is the most common failure we’re called in to fix after another builder walked away. Call (877) 610-1318 for a foundation assessment before you frame.
We write allowances into your contract for the conditions we expect to find, and when we expose something that wasn’t anticipated, we stop and hand you a written change order with the exact scope and price before we proceed. No surprise invoices at the end. The allowance that isn’t on paper is a surprise waiting for a date, so we put it on paper from the beginning. On a Carrollton room addition, that often means framing repairs, panel upgrades, or slab releveling that a lazy builder would bury in the final bill. We don’t do that. Call (877) 610-1318 and ask Tom Barrett how allowances work on your specific project.
Yes, many Carrollton homeowners finance ADU construction through construction loans, home equity lines, or renovation loans, and we work with the draw schedule your lender requires. A draw schedule releases funds at defined milestones, like foundation completion, rough-in inspection, and final sign-off, and we align our work to those milestones so your lender’s inspector and Carrollton’s inspector are never at odds. Because we pull permits and get inspections signed on every eligible job, your draw requests have the paperwork lenders want. Call (877) 610-1318 and we’ll walk you through how our billing aligns with a typical Carrollton ADU construction loan.
If you’re planning a home addition or ADU in Carrollton, call Barrett & Sons Construction at (877) 610-1318 for a free estimate. We’ll send someone who knows your ZIP, your soil, and your city’s permit path. The quote will be in writing, and it’ll be real.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Carrollton since 1998.