Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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After
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AfterFast, Reliable Home Additions & ADU Across Flower Mound
Adding square footage to a Flower Mound home usually costs between $45,000 and $130,000 for a room addition, and $90,000 to $220,000 for a detached ADU, depending on scope, foundation work, and whether the property sits inside a flowage easement along Grapevine Lake. We’ve built additions and ADUs across the 75022, 75027, and 75028 zip codes for over two decades, and we know the Flower Mound permitting path better than most because we’ve walked it hundreds of times. If you’re weighing a second-story addition off Morriss Road or a garage conversion in Bridlewood, call (877) 610-1318 for a free estimate and a straight conversation about what’s realistic on your lot.
What sets Flower Mound apart from neighboring cities is the layering of regulatory bodies between you and a finished addition. The Army Corps of Engineers boundary along Grapevine Lake, master-planned HOA design review boards, and Denton County’s expansive clay soils all shape what can be built, where it can sit, and how it must be engineered. A contractor who treats your addition like a generic suburban project is going to hit a wall mid-permit. We don’t, because we’ve pulled those permits before.
Why Barrett & Sons Construction Is Flower Mound’s Preferred Home Additions & ADU Company
Barrett & Sons is owner-operated, and Tom Barrett’s name, address, and license number are published for anyone to look up before signing a contract. That matters in Flower Mound, where homeowners have been burned by national outfits that quote one number on the phone and hand over a different bill at the door. Our 90-Day Done Right Promise is written into every contract: if something isn’t done right, one call brings Tom back to make it right.
Flower Mound homeowners regularly tell us what they’re really looking for: a contractor who pulls permits, issues written change orders before any scope change, and doesn’t vanish after the final check clears. The permit inspector works for you, not for me, and we like it that way. On additions and ADUs in Wellington, The Highlands, and along the Grapevine Lake shoreline, we’re on-site with named crew members, not dispatched labor. And a live person answers the phone at (877) 610-1318 around the clock.
We also carry premium brands across the trades that feed into additions: GAF on roofing, Schluter in wet areas, and Sterling for plumbing fixtures in new bathrooms. These are materials you can look up, not mystery brands off a van.
Our Home Additions & ADU Services in Flower Mound
Every addition we build in Flower Mound starts with the same question: what does the lot actually allow? We’ve seen too many homeowners sketch a detached ADU, only to discover their rear yard falls inside the Corps of Engineers 532-foot elevation line. Our Home Additions & ADU team checks that before you spend a dollar on design.
ADU Design & Permitting
ADU permitting in Flower Mound runs through the town’s building department, but properties near Grapevine Lake often require a parallel COE Section 404 or floodplain compliance review. We handle both tracks, plus any HOA design-review submission in Bridlewood, Wellington, or The Highlands. You get one point of contact, and every approval step arrives in writing.
Garage Conversion ADU
Converting an attached garage into a rental unit or in-law suite typically runs $30,000 to $80,000 in Flower Mound, depending on whether you’re adding plumbing, expanding the footprint, or just finishing the envelope. The 1990s brick-facade tract homes that dominate Flower Mound’s housing stock usually have post-tensioned slabs, which means cutting new plumbing lines requires a structural engineer’s sign-off before we trench anything.
New Detached ADU
A ground-up detached ADU in Flower Mound runs $90,000 to $220,000, and the biggest variable is foundation design. Blackland Prairie clay expands in spring and fractures in August, so we specify pier-and-beam or engineered slab systems that isolate the structure from seasonal movement. That’s not optional in Denton County; it’s the difference between a building that stays square and one that racks its doors within five years.
Junior ADU & Interior Conversion
For homeowners who want a private suite without the full permitting gauntlet, a junior ADU carved from existing interior square footage, often a finished attic or oversized bonus room, makes sense. These projects frequently cross over with Kitchen Remodeling in Flower Mound and Bathroom Remodeling in Flower Mound, since a true ADU needs its own kitchenette and bath. We coordinate all three scopes under one contract.
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 Flower Mound
We stock and install materials our Flower Mound customers can verify by name. GAF shingles and underlayment on any addition that ties into the existing roofline, so the new section is indistinguishable from the original. Schluter waterproofing systems in ADU bathrooms and kitchenettes, because wet areas fail quietly and expensively on clay soils where slab movement is constant. Sterling plumbing fixtures in secondary baths and ADU wet bars, chosen for durability and serviceable parts. When a Flower Mound homeowner asks what we’re using and why, there’s a real answer with a real brand behind it.
Common Home Additions & ADU Problems We See in Flower Mound Homes
- Corps of Engineers easement surprises.
Properties in Twin Coves, Heron’s Run, and other lake-adjacent areas of Flower Mound regularly discover mid-project that their rear yard sits inside the 532-foot elevation line. That halts deck, fence, and outbuilding permits until a COE Section 404 review is complete, a delay out-of-area contractors don’t anticipate and homeowners can’t afford.
- Foundation movement under new additions.
Flower Mound sits on some of the most expansive clay in the DFW metro. Slab prep and drainage grading around any new structure have to account for the shrink-swell cycle, or the addition will crack away from the original framing within a few seasons.
- HOA design-review conflicts.
Bridlewood, Wellington, and The Highlands enforce architectural review processes that add weeks to a timeline. We’ve walked HOA boards through elevation drawings, roofline matching, and material specs enough times to know what gets approved and what gets kicked back.
- Post-tensioned slab complications.
Most Flower Mound homes built between 1990 and 2015 have post-tensioned slab foundations. Cutting into one for new plumbing or a master-suite tray ceiling requires X-ray location and an engineer’s stamp, not just a concrete saw.
Pricing for Home Additions & ADU in Flower Mound, TX
A room addition in Flower Mound runs $45,000 to $130,000. A detached ADU runs $90,000 to $220,000. A garage conversion runs $30,000 to $80,000. Those ranges reflect what we see across 75022, 75027, and 75028: foundation engineering, HOA design review, permitting, materials, and labor. What pushes a project toward the high end is usually site-specific, Corps easement coordination, a second story, high-end fixtures, or clay-driven foundation remediation before framing begins.
Every flower Mound quote we write is line-itemed. Every allowance is named. Every change order arrives on paper before work proceeds. An allowance that isn’t on paper is a surprise waiting for a date. We never spring a number at the end that wasn’t in writing up front. Call (877) 610-1318 to schedule a free estimate, and we’ll walk the lot with you before we put anything in writing.
We Also Serve Cities Near Flower Mound
Our crews regularly run additions and ADUs in Flower Mound and the surrounding communities of Highland Village, Lantana, Corinth, and Lake Dallas. The permitting landscape changes at every city line, and we keep current on all of them. Wherever your lot sits, the same owner-operated crew shows up with the same written-change-order discipline.
Serving Flower Mound, TX - Our Local Coverage Area
We’re based in the Flower Mound 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 Flower Mound
After the estimate is accepted and permits are filed, most Flower Mound additions begin site work within three to six weeks. The permitting timeline is the real variable here, especially on properties near Grapevine Lake where COE coordination can add two to four weeks that no contractor can compress. Call (877) 610-1318 and we’ll give you an honest start-date range for your specific lot, free.
Yes. We pull permits and manage inspections in 75022, 75027, and 75028, including the lake-side neighborhoods where Corps of Engineers review runs parallel to the town’s building department. We’ve also navigated HOA design-review boards in Bridlewood, Wellington, and The Highlands.
Flower Mound additions run $45,000 to $130,000, which is in line with Highland Village and Corinth but slightly higher than some fast-permit suburbs to the east, largely because lake-adjacent lots trigger engineering and COE review that flat prairie lots don’t. You’re not paying more for the same work; you’re paying for the regulatory and soil conditions your specific lot imposes.
Every Barrett & Sons addition and ADU carries the written 90-Day Done Right Promise. If something isn’t done right, Tom Barrett comes back and makes it right, one call. We also honor manufacturer warranties on every named brand we install, from GAF roofing to Schluter waterproofing.
The Blackland Prairie clay under Flower Mound swells during spring rains and shrinks during summer drought, which stresses any slab or footing that wasn’t engineered for it. We specify foundation designs that isolate new structures from that movement, including engineered piers where the soil boring calls for it. Foundation shortcuts aren’t a savings in Denton County; they’re a five-year crack waiting to happen.
If you’re ready to talk about an addition or ADU on your Flower Mound lot, call (877) 610-1318. Tom or one of his sons will answer, ask about your property, and schedule a free estimate. No pressure, no surprise invoices, and everything in writing before a single nail moves.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Flower Mound with honest, written-in-advance home additions and ADU work.