Home Additions & ADU in McKinney - One Fixed Price, Permits Handled

Fast, Reliable Home Additions & ADU Across McKinney

Most McKinney homeowners call us after they’ve outgrown a house they love. Maybe it’s a parent moving in and you need a first-floor suite off the back of the house in Craig Ranch. Maybe your son is 28, back from Austin, and the guest room isn’t cutting it anymore, so you’re weighing a detached ADU out by the alley in 75070. Or you bought a Victorian near Chestnut Square in 75069 and the original floor plan simply doesn’t work for a modern family. Whatever pushed you here, you want a straight answer about whether adding on makes sense, what it costs, and who you can trust not to turn your savings into a punch list of “extras” at the end.

Call (877) 610-1318

Here’s the straight answer up front: a home addition in McKinney typically runs $45,000 to $130,000, and a full detached ADU usually lands between $90,000 and $220,000 depending on size, finishes, and what the soil does when we dig. We’re Barrett & Sons Construction. Tom Barrett and his sons run the crews, every permit gets pulled, every price change arrives in writing before work starts, and a live person answers the phone when you call. Call (877) 610-1318 for a free estimate on your project.

We’ve worked in McKinney long enough to know that no two lots behave the same here. That’s not contractor filler, it’s Blackland Prairie fact. We’ll get into that below, because it shapes what we recommend and what we quote.

Why Barrett & Sons Construction Is McKinney’s Preferred Home Additions & ADU Company

Barrett & Sons started in 1998 as a father-and-sons operation, and that’s still what it is. When we say owner-operated, we mean Tom Barrett is on job sites in McKinney most weeks, and his sons run crews with their names stitched on the trucks. You won’t get a dispatcher in another state, and you won’t get a project manager who’s never swung a hammer. You’ll get the same faces from the first estimate to the final inspection.

McKinney homeowners regularly tell us the same story: a national company quoted one number on the phone and handed them a different bill at the door. That’s exactly the thing we built this company against. Every scope, every allowance, every price change gets issued as a written change order before a single nail moves. No surprise invoices at the end. The permit inspector works for you, not for me. That’s why I like him, Tom says. And tom’s name, address, and license number are published. Look them up before you sign anything.

Our Home Additions & ADU team carries a 90-Day Done Right Promise written on every contract. If something’s not right, one phone call brings Tom back. That’s not a warranty buried in fine print. It’s a promise from a guy who lives twenty minutes away and plans to see you at the hardware store on Saturday.

Our Home Additions & ADU Services in McKinney

These are the projects we’re handling most often across McKinney right now. If yours doesn’t fit neatly into one box, call and talk it through. Scope in writing, allowances in writing, change orders in writing, and then we build.

ADU Design & Permitting

McKinney’s zoning for accessory dwelling units shifted in recent years, and the requirements vary from one subdivision to the next. In 75070 and 75071, many HOAs in Craig Ranch and Tucker Hill have their own rules layered on top of city code. We handle the full design and permitting path, including utility tie-in plans and the Blackland Prairie soil documentation the city wants before foundation approval. You’ll know exactly what’s allowed on your lot before you spend a dollar on drawings.

Garage Conversion ADU

A garage conversion in McKinney typically costs $30,000 to $80,000 and is often the fastest way to add a rentable or family suite without changing the home’s footprint. We see a lot of these in the production-built homes in Erwin Farms and around 75071, where oversized two-car garages from the 2005 to 2013 build cycle sit on the back corner of lots with easy alley access. The big variable is what we find behind the drywall: slab flatness, drainage grading, and whether the original builder left proper moisture barriers.

New Detached ADU

A detached ADU in McKinney runs $90,000 to $220,000 depending on square footage, foundation requirements, and interior finishes. Detached units on Blackland Prairie clay almost always need a deeper, more expensive foundation detail than a builder in sandier soil would quote. We’ll tell you that on day one, not when the concrete truck shows up. We handle site prep, utility runs, and full finish-out to match or complement the main house.

Junior ADU & Interior Conversion

A junior ADU converts existing interior space, often an upper-floor bonus room or a walk-out lower level, into a semi-independent suite with a small kitchenette and private entry if the layout allows. These projects in Home Additions & ADU in McKinney homes tend to be lighter lifts on the foundation side, but plumbing stack relocation and egress requirements add cost. We pull permits and pass inspections on every one, and we’ll show you where the money is going before we start.

Trusted Brands We Service in McKinney

We install materials you can look up, not mystery brands off a van. On hardscape and site work tied to additions and ADU foundations across McKinney, we regularly use Techo-Bloc, Cambridge Pavers, and Quikrete products. These are premium lines built for North Texas soil conditions, and we stock the common fasteners, drainage components, and finish materials locally so a small supply snag doesn’t stall your schedule for a week. When the brand name is on the truck and the receipt, nobody has to take our word for it, though you’re welcome to.

Common Home Additions & ADU Problems We See in McKinney Homes

• Clay-soil foundation movement before a single new footing is poured. The Blackland Prairie clay under much of McKinney shrinks hard in summer and swells after rain, and a 15-year-old volume-built home in 75070 often settles unevenly. We build slab and drainage assessment into every estimate so we’re not discovering a step-cracked brick veneer mid-project.
• Inadequate original lot grading in 75070 and 75071. Builders grading for speed during the 2005 to 2013 surge left many lots with almost no slope away from the slab. After a decade-plus of wet-dry cycling, we routinely see sheetrock separation and brick cracking before remodel scope even begins. Fixing grading is the most common unglamorous first line item on our McKinney additions.
• Historic overlay constraints in 75069. In the Chestnut Square district and surrounding downtown blocks, early-1900s Craftsman and Victorian homes carry strict material and method requirements. You cannot swap a window or add a dormer without preservation review, and that’s a good thing for the neighborhood, but it changes cost and timeline. We navigate those approvals as part of the permit package.
• Utility capacity surprises on ADU builds. Many post-2000 subdivision lots in Craig Ranch and Tucker Hill were plumbed and wired with barely enough capacity for the original house. Adding a full ADU with a second kitchen and laundry can max out the existing service. We check panel capacity, sewer depth, and water meter size early so the change order is written before the drywall goes up, not after.

Pricing for Home Additions & ADU in McKinney, TX

We Also Serve Cities Near McKinney

We serve homeowners throughout McKinney, and our crews regularly work in Fairview, Melissa, Allen, and Princeton. If you’re just outside the 75069, 75070, or 75071 ZIPs, call us anyway. The same crews, the same written pricing, the same 90-Day Done Right Promise applies. And while you’re planning an addition, remember that Kitchen Remodeling in McKinney and Bathroom Remodeling in McKinney often make sense to fold into the same permit cycle as your addition project. We’ll walk you through whether it’s cheaper to combine scopes or run them separately.

FAQs - Home Additions & ADU in McKinney