Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Lucas
Home additions and ADU construction in Lucas, Texas typically run $45,000-$130,000 for a room addition, while a detached ADU with site prep, septic coordination, and utility runs will land between $90,000 and $220,000. Those numbers reflect something specific about Lucas that most contractors in Collin County never confront: the 2-acre minimum lot size ordinance that has kept this town an enclave of custom estate properties rather than tract housing. A project here isn’t a paint-by-numbers job. It’s site planning across a big parcel, drainage work that accounts for Blackland Prairie clay, and in many cases, Collin County Environmental Health sign-off on septic capacity before a building permit moves an inch. If you’re looking at a room addition off the back of a 1990s custom home on a wooded lot off Country Club Road, or a detached ADU near Lake Forest Drive where the sewer line isn’t an option, you need a crew that has done that kind of work before. That’s what we do. Call (877) 610-1318 and Tom Barrett or one of his sons will talk through your lot, your plans, and what’s realistic before you spend a dollar.
Why Barrett & Sons Construction Is Lucas’s Preferred Home Additions & ADU Company
Barrett & Sons Construction is owner-operated, founded in 1998 and run by Tom Barrett with his sons leading the crews. That matters in a town like Lucas, where neighbors know each other and the name on the truck carries weight. We’re proud to serve Lucas homeowners, and our reputation is built one project at a time: permits pulled and inspections signed on every eligible job, written change orders before any scope change touches the work, and the 90-Day Done Right Promise written into every contract. If something isn’t right after the job is done, one call brings Tom back to make it right.
Our team covers Lucas from the 75002 ZIP code across Lake Forest Drive, Stinson Road, and the custom acreage around Hart Road. We’re on-site regularly, not dispatching strangers from a call center. Tom publishes his name, address, and license number so you can look him up before you sign anything. And when you call, a live person answers 24/7, not a voicemail box. When a Lucas homeowner needs an honest look at an ADU feasibility question or a quote on a second-story addition, we’re the local crew that shows up on time and stands behind the work.
Our Home Additions & ADU Services in Lucas
We offer a full range of Home Additions & ADU services in Lucas, each tailored to the lot, the existing structure, and the county regulations that come with building on large custom parcels. Here are the four services Lucas homeowners call us about most.
ADU Design & Permitting
Accessory dwelling units in Lucas are rarely a simple drop-a-shed-in-the-yard project. Because much of Lucas predates municipal sewer service, an ADU design has to account for septic capacity, setback rules across multi-acre lots, and foundation engineering that handles Blackland Prairie clay movement. Our team manages the design and permitting process end to end, including Collin County Environmental Health reviews when the project requires them. You’ll get scope in writing and allowances in writing before anything gets built.

Garage Conversion ADU
A garage conversion ADU in Lucas commonly runs $30,000-$80,000, depending on whether the attached garage is being converted within its existing footprint or expanded. We see a lot of these on late-1990s custom estate homes where the original three-car garage has outlived its purpose and the homeowners want a self-contained living space for aging parents or adult children. Every conversion we do includes a structural review of the existing slab, because expansive clay soil in Lucas has cracked more than a few original garage floors.

New Detached ADU
A new detached ADU in Lucas is a serious build, typically $90,000-$220,000 when you factor in foundation piers, utility extensions across the parcel, and septic or sewer coordination. On a 2-acre lot near Stinson Road or off Hart Road, the distance between the main house and the ADU site can add real cost in trenching and drainage. We plan for that up front with written estimates that reflect actual site conditions, not a generic spreadsheet number.

Junior ADU & Interior Conversion
A junior ADU, or an interior conversion that creates a semi-independent living space within the existing home footprint, often makes more sense for Lucas homeowners who want flexibility without a full detached build. These projects usually run $45,000-$100,000 depending on whether we’re adding a kitchenette, a private entrance, or converting existing square footage. This is a popular path for families caring for aging parents while preserving the big-acreage character of their property.

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 Lucas
We install and work with premium brands you can look up, not mystery products off the back of a van. For Lucas addition and ADU Windows & Doors - Lucas, we regularly install Simonton and Ply Gem units, both proven to handle North Texas heat gain and spring storm cycles. For impact-rated openings on southern exposures or lake-facing sides, PGT products hold up well to hail and wind. Because we spec these brands regularly, we can get replacements and parts through our suppliers quickly, which keeps a Lucas project moving when a window lead time might otherwise stall it. Every brand we install comes with the manufacturer’s warranty and our own written 90-Day Done Right Promise on top.
Common Home Additions & ADU Problems We See in Lucas Homes
Working across Lucas means seeing the same problems show up on custom estates time after time:
- Blackland Prairie clay movement: The expansive black clay under Lucas swells with spring rains and cracks in summer drought. An addition that isn’t engineered on piers or a post-tensioned slab can move visibly within two seasons. We design every Lucas foundation with that movement in mind.
- Septic capacity surprises: Many Lucas parcels aren’t connected to municipal sewer, and an addition that adds bedrooms or a bathroom can push septic capacity past its limit. Collin County Environmental Health may require a system upgrade before a permit clears. We plan for that review from day one.
- Aging 1990s custom framing: The dominate stock in Lucas was built from roughly the late 1990s through the 2010s, and those original structures are now entering a renovation cycle. Tie-in points between old framing and new addition framing often need reinforcement or correction before the addition roof ties in cleanly.
- Long drainage and utility runs: On a 2-acre lot, the addition or ADU site may sit 100 to 200 feet from the existing electrical panel, water line, or drainage swale. Underestimating those runs is the single biggest source of surprise invoices from contractors unfamiliar with Lucas. We price the full run in the original scope, in writing.
Pricing for Home Additions & ADU in Lucas, TX
For planning purposes, a room addition in Lucas runs $45,000-$130,000. A garage conversion ADU is typically $30,000-$80,000. A new detached ADU starts around $90,000 and can reach $220,000 depending on foundation depth, utility distance, and septic work. A junior ADU or interior conversion generally falls between $45,000 and $100,000. What moves the number in Lucas specifically: lot size and utility runs, whether the parcel is on sewer or septic, the condition of the existing foundation, and the finish level you want on the new space. We give honest, itemized estimates with the scope in writing so you can compare line by line. The estimate is free, and so is a second opinion on any other written estimate. Call (877) 610-1318 to schedule yours.
We Also Serve Cities Near Lucas
While this page is focused on Lucas, our crews also serve homeowners in the wider Lucas area and nearby communities including Allen, Murphy, Plano, and Fairview. We also handle Kitchen Remodeling in Lucas and Bathroom Remodeling in Lucas when your addition project includes updating the main house.
Serving Lucas, TX - Our Local Coverage Area
We’re based in the Lucas 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 Lucas
A room addition in Lucas typically costs $45,000-$130,000. The final number depends on whether your parcel is on sewer or septic, how far the utilities need to run across your lot, and the condition of the existing foundation. Call (877) 610-1318 for an exact quote; estimates are free and itemized in writing.
Yes, in many cases. Many Lucas parcels fall outside municipal sewer reach, so a new or expanded living space often triggers a Collin County Environmental Health review of septic capacity before a building permit will be issued. We handle that coordination as part of the design and permitting scope so it doesn’t surprise you mid-project. Call (877) 610-1318 to talk through your specific lot.
Most Lucas addition and ADU projects can start within a few weeks of signing, depending on permit review timelines with Collin County and any septic clearances required. We provide a written schedule at contract signing and issue written change orders if any conditions on site change the scope. Call (877) 610-1318 for a free estimate and a realistic start date.
Often yes, because Lucas lots are larger and many properties require septic coordination and longer utility runs that fully sewered cities like Allen and Plano don’t have to address. Expect the foundation and site work portion of a Lucas ADU to run higher than a comparable build in a suburban subdivision. Call (877) 610-1318 and we’ll walk you through where the money goes on your specific property.
Every addition and ADU we build in Lucas is backed by our written 90-Day Done Right Promise: if it isn’t done right, one call brings Tom Barrett back to make it right. That’s in addition to manufacturer warranties on the materials we install. Call (877) 610-1318 to schedule your free estimate and see the written guarantee before you commit.
Get Your Home Addition or ADU Started in Lucas
If you’re planning a room addition, a garage conversion, or a detached ADU on your Lucas property, start with a conversation. Call (877) 610-1318 to schedule a free estimate with Barrett & Sons Construction. You’ll get honest pricing, a written scope, and the name of the man who will be on your job site, not a faceless national outfit. We’re proud to serve Lucas and the surrounding Collin County communities, and we’d be glad to walk your lot and talk through what’s possible - whether you need a room addition, ADU, or Lucas Roofing work as part of your project.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Lucas, Allen, Murphy, Plano, and Fairview since 1998.







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