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 DeSoto
Home additions and ADU construction in DeSoto typically run between $45,000 and $130,000 for a full addition, with garage conversions landing closer to $30,000 to $80,000. The single biggest variable in this city is what’s under your feet: DeSoto’s Blackland Prairie clay moves more than almost any soil in North Texas, so every project starts with a foundation and drainage assessment before we ever talk framing. Barrett & Sons handles that from day one. Call (877) 610-1318 for a free estimate and we’ll walk your lot, check the grade, and give you a written scope you can hold us to.
Why Barrett & Sons Construction Is DeSoto’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews that show up in DeSoto. That’s not marketing language; it’s how the schedule works. When you call about a room addition in the 75115 ZIP or a detached ADU off Belt Line Road, the person answering is someone who knows the difference between a 1970s post-tension slab and a 1990s conventional pour, because we’ve worked both across this city for decades. Tom publishes his name, address, and license number, and he’ll tell you to look it up before you sign anything.
DeSoto homeowners tend to ask the same questions before hiring: who’s actually on-site, what happens when the price changes, and what do we do about the permit. Here’s how we answer. The sons are on-site most days. Every price change comes as a written change order before work proceeds. And every eligible job includes permits pulled and inspections signed, because the permit inspector works for you, not for us. A live person answers our phone 24/7, so when you call at 9 p.m. worried about a crack that just opened above a door header, you get Tom or one of his sons, not a voicemail box.
Our Home Additions & ADU Services in DeSoto
ADU Design & Permitting
DeSoto’s permit office requires stamped plans for any accessory dwelling unit, and the soil report is not optional on this clay. We handle the full design and permitting path: property survey, foundation engineering, city submittal, and the inspection schedule. Most DeSoto ADUs we permit fall between $90,000 and $220,000, though a permitted garage conversion often comes in under that. Tom’s approach is to get the scope in writing before the first form goes up, because an allowance that isn’t on paper is a surprise waiting for a date.
Garage Conversion ADU
DeSoto has thousands of two-car attached garages from the 1980s and 1990s suburban boom, and a garage conversion is usually the fastest path to an income unit or a private suite for aging parents. These projects run $30,000 to $80,000 depending on whether you’re keeping the slab, adding a bathroom, and the condition of the existing walls. One thing we check before quoting any DeSoto garage conversion: the original pour depth. Many of those 1980s slabs were never engineered for living space or plumbing trenches, and cutting into undersized concrete costs more than most homeowners expect.
New Detached ADU
A new detached ADU in DeSoto means a full foundation pour on Blackland Prairie clay, and that foundation is where the cost and the risk live. We typically see these projects running $90,000 to $220,000 fully permitted and finished. The catch on many DeSoto lots is rear-yard drainage. Decades of fence-line soil compaction and neighbor-to-neighbor drainage disagreements have left a lot of backyards with reversed slope, and the addition permit will force you to correct that before we pour. We scope it upfront so you’re not paying for a surprise regrade mid-project.
Junior ADU & Interior Conversion
A junior ADU carved out of an existing home, like a converted bonus room with a kitchenette and private entrance, usually lands in the $45,000 to $130,000 range depending on plumbing and egress work. In DeSoto, many 1980s split-levels have a lower-level space that works well for this. We also handle full room additions and second-story additions. If you’re adding square footage, plan for the conversation about your existing HVAC chase and whether the current unit can carry the new load; many of the original single-pane windows and 1970s-era chases we find in DeSoto were never sized for added rooms.
If you’re already thinking about a larger remodel alongside the addition, our Kitchen Remodeling in DeSoto team works the same job sites and coordinates schedules so you’re not living through two separate disruptions. Same goes for Bathroom Remodeling in DeSoto when the addition includes a new full bath or a primary suite expansion.
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 DeSoto
We’re not a mystery-brand operation. The materials we price into DeSoto projects carry names you can look up: GAF for our Roofing in DeSoto tied to an addition, Schluter for waterproofing in new baths, and Sterling for fixtures in ADU kitchens and bathrooms. When a DeSoto homeowner wants to compare what we’re quoting against what the brand lists, we want them to do exactly that. That’s the whole point of a written scope: you can verify the line items before the work starts, not after the invoice shows up.
Common Home Additions & ADU Problems We See in DeSoto Homes
- Slab movement under existing walls. Blackland Prairie clay shrinks in the summer and swells in the winter, and many 1970s-1990s slabs in DeSoto are at the age where that movement shows as brick cracks and racked door frames. Any addition tied to that slab needs a foundation check first.
- Rear-yard drainage that flows the wrong way. On older subdivision lots, we regularly find the grade pitches toward the house instead of away. A competent addition permit will catch this, and the correction is on you unless it’s scoped before you sign.
- Original single-pane windows and undersized HVAC. Many DeSoto homes from the 1970s and 1980s still have the original windows and mechanical chases. When you add square footage, the existing HVAC often can’t carry the load, and that’s a conversation you want to have before framing, not after drywall.
- Aluminum wiring in the oldest tier. Homes from the early 1970s in DeSoto sometimes still have aluminum branch circuits. Any addition that ties into that panel means a load calculation and, in many cases, a panel upgrade. We don’t hide that in an allowance; it goes on paper as a specific line item.
Pricing for Home Additions & ADU in DeSoto, TX
Here’s the honest math for DeSoto. A full room addition lands between $45,000 and $130,000. An ADU runs $90,000 to $220,000. A garage conversion falls between $30,000 and $80,000. What moves the number: foundation work on the clay, whether you’re adding a bathroom, the siding and roof tie-in, and how much of the existing HVAC and electrical needs upgrading. We give you a written, line-item quote before you commit, and if the scope changes, the change order arrives in writing before the work does. The 90-Day Done Right Promise is written on every contract: if it’s not done right, Tom comes back and makes it right, one call. Call (877) 610-1318 to schedule your free estimate.
We Also Serve Cities Near DeSoto
Our crews live and work all over southern Dallas County. Beyond DeSoto, we’re regularly in Glenn Heights, Lancaster, Cedar Hill, and Duncanville, which means scheduling doesn’t hinge on a dispatcher three states away. If you’re in one of those cities and looking at an addition or ADU, the same team that quotes your neighbor in DeSoto will be the one swinging the hammer. For our full local service hub, see Home Additions & ADU in DeSoto.
Serving DeSoto, TX - Our Local Coverage Area
We’re based in the DeSoto 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 DeSoto
A home addition in DeSoto typically costs between $45,000 and $130,000 depending on size, foundation requirements, and whether you’re adding a bathroom or kitchen space. Garage conversions run $30,000 to $80,000, while a new detached ADU is $90,000 to $220,000. Give us a call at (877) 610-1318 and we’ll give you a written, line-item quote for your specific lot and scope.
Yes. Every eligible job includes permits pulled and inspections signed. In DeSoto, the permit office requires engineered plans for ADUs and additions, and the soil report is part of that because of the Blackland Prairie clay. We handle the full submittal and inspection schedule so you don’t have to chase the city.
Only if the scope changes, and if it does, you’ll receive a written change order before any work proceeds. We don’t do surprise invoices at the end. The 90-Day Done Right Promise is on every contract, and Tom’s name is on the permit.
Most room additions in DeSoto take between 10 and 16 weeks from permit approval to final inspection, depending on foundation work and material lead times. A detached ADU usually runs longer, often 5 to 8 months, because of the full foundation pour and utility work. We’ll give you a realistic schedule in writing before you sign anything, based on your specific project, not a generic timeline.
Yes, and in DeSoto it’s almost always part of the conversation. The clay under most 1970s-1990s slab homes here moves enough that we evaluate the existing foundation before we design anything new. If there’s active movement, we bring in a foundation specialist and fold that into the written scope so you’re not surprised mid-project. Call (877) 610-1318 to have us look at your lot.
Contact Barrett & Sons Construction for Home Additions & ADU in DeSoto
If you’re considering a room addition, garage conversion, or detached ADU in DeSoto, don’t sign anything until you’ve had Tom or one of his sons walk your property. We’ll check the grade, look at the slab, and give you a written, line-item estimate with no trip charge inside the county. Our Home Additions & ADU team has been doing this since 1998, and we stand behind every job with the 90-Day Done Right Promise. Call (877) 610-1318 today to schedule your free estimate.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving DeSoto since 1998.