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 Frisco
Adding square footage or an ADU in Frisco typically runs $45,000 to $130,000 for a room addition, and $90,000 to $220,000 for a new detached ADU, with permit-ready engineering included. That range doesn’t come from a national price book. It comes from what we actually see on Frisco job sites, where Blackland Prairie clay, HOA architectural committees, and a Building Inspections department that demands third-party engineering on structural work all shape the final number. Call (877) 610-1318 to talk through your project with someone who knows the difference between a Frisco build and one twenty minutes north.
Why Barrett & Sons Construction Is Frisco’s Preferred Home Additions & ADU Company
We’re not a franchise dispatching strangers to Frisco. Tom Barrett founded this company in 1998, and his sons run the crews. When a homeowner in The Trails or Starwood asks who’s going to be on-site, the answer is a name you can verify, not a rotating cast. Our Home Additions & ADU team has pulled permits in Frisco enough times to know exactly what the plan reviewer will flag before we even submit.
Frisco homeowners call us because the city’s inspection standards are genuinely strict, and we like it that way. The permit inspector works for you, not for me. That’s why every structural addition we do in Frisco includes stamped engineering calculations, a documented continuous load path, and a permit card posted where you can see it. We also know the master-planned community HOA drill: exterior elevations, window styles, brick color, roof pitch. If the architectural committee takes 11 days to approve something, we already planned for that.
Every scope, every allowance, every price change arrives as a written change order before work happens. No surprise invoices at the end. No “the allowance isn’t on paper” conversations. And every job carries the 90-Day Done Right Promise, written on the contract: if it’s not done right, Tom comes back and makes it right, one call.
Our Home Additions & ADU Services in Frisco
ADU Design & Permitting
A Frisco ADU starts on paper, and that paper has to satisfy two audiences: the City of Frisco Building Inspections department and, in most master-planned communities, an HOA architectural review board. We handle both. Our designs go out with third-party engineering documentation from the first submittal, because we’ve watched too many Frisco homeowners get a permit pulled, then have the plan review come back requiring stamped calcs they didn’t budget for. In Frisco, the engineering isn’t optional, so we build it into the estimate from day one.
New Detached ADU
Building a detached ADU in Frisco means putting a new structure on expansive clay, and that’s where a cheap quote falls apart. We size foundation systems for the actual soil conditions under your lot, not a generic slab detail. A new ADU over Frisco’s montmorillonite clay without proper foundation design can heave enough in the first wet spring to crack interior tile and rack door frames. We don’t build that way. Our Frisco ADUs get engineered foundations, wind-rated roof framing, and a permit card that documents every inspection that was signed.
Garage Conversion ADU
Converting a garage in Frisco’s 2000s-era production homes means working with whatever the original builder actually poured, which is rarely what the blueprints say. We verify the slab, the existing framing, and the electrical service before we quote a number. Garage conversions in Frisco run $30,000 to $80,000 depending on whether you’re keeping it simple or adding a full kitchen and Bathroom Remodeling in Frisco. Either way, the conversion gets the same permit scrutiny as new construction, and we treat it like exactly what it is: a structural change to your home, not a weekend project.
Junior ADU & Interior Conversion
A junior ADU built inside your existing Frisco floor plan is often the most cost-effective way to add a rentable or multigenerational unit. We’re usually working with interior load-bearing walls, which still requires the City’s third-party engineering documentation when we relocate or remove them. The good news is that interior conversions often move faster through HOA review, since there’s no exterior elevation change. The bad news is that the same plan review standards apply. We handle both sides of that equation.
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 Frisco
When we build an addition or ADU in Frisco, the materials carry names you can look up. For hardscapes and flatwork around a new ADU, we install Techo-Bloc and Cambridge Pavers products, and we use Quikrete for slab and footing work across Frisco’s clay-heavy lots. These aren’t mystery brands off a van. They’re materials with published specs, which matters when the City of Frisco asks for product documentation during plan review. We order directly from local DFW suppliers, so lead times on these brands stay short for Frisco projects.
Common Home Additions & ADU Problems We See in Frisco Homes
- Third-party engineering skipped entirely. A contractor builds the addition with conventional prescriptive framing because it passed in a neighboring city. Frisco’s plan review flags it, and the homeowner pays for a redesign after the permit was already pulled. We submit stamped calcs before framing starts, every time.
- HOA architectural review treated as an afterthought. An exterior addition starts without committee approval, and the board requires a mid-project change order to fix window style, brick color, or roof pitch. In Frisco’s master-planned communities, this is the most preventable schedule killer we see.
- ADU foundation not designed for Frisco’s expansive clay. A new detached unit gets a conventional slab, and the first wet spring heaves it. Cracked tile, racked doors, voided warranty, an insurance dispute. On Frisco’s Blackland Prairie, foundation engineering is not a line item to cut.
- Wind-load documentation missing from the roof structure. Frisco sits in a wind zone where roof-to-wall connections have to be engineered and documented. A cheap framing job that skips the continuous load path may pass a drive-by look and fail the structural inspection. We frame to the wind rating and keep the documentation with your permit file.
Pricing for Home Additions & ADU in Frisco, TX
Here’s what you should expect to budget for a permitted, wind-rated, engineer-stamped project in Frisco. These numbers reflect current local labor and material costs across 75033, 75034, and 75035, and they include the engineering and permit documentation the City requires on structural work.
| Project Type | Frisco Price Range |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Second Story Addition | $45,000 - $130,000 |
| Garage Conversion ADU | $30,000 - $80,000 |
What moves the number? Soil conditions on your specific Frisco lot, the structural documentation the City requires for your scope, HOA exterior requirements, and the finish level you choose. A compliant quote includes stamped engineering, a permit package that clears plan review, and written change orders for every adjustment. A cheap quote leaves those out and hopes the inspector doesn’t notice. Call (877) 610-1318 for a free, written estimate, no trip charge inside the county.
We Also Serve Cities Near Frisco
Beyond Frisco, we run crews to Prosper, The Colony, Little Elm, and Celina. Each city has its own inspection culture and soil profile, but the same rule applies everywhere we work: permits pulled, engineering documented, change orders in writing. If you’re looking for Home Additions & ADU in Frisco or a neighboring community, call us and we’ll tell you straight what your job will take.
Serving Frisco, TX - Our Local Coverage Area
We’re based in the Frisco 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 Frisco
Yes. Frisco’s Building Inspections department requires third-party engineering documentation for any structural addition, including a second story added over a 2003-era builder slab. That means before we frame the first wall, a licensed engineer verifies the existing foundation for the added load and specifies continuous load paths from ridge to slab. We submit those stamped calcs with the permit application. A quote that doesn’t include this engineering work is not a real Frisco quote. Call (877) 610-1318 for an exact number on your project.
A Frisco ADU has to meet the wind-load requirements in Frisco’s adopted building code, which means the roof structure needs engineered connections from roof deck to wall to foundation, not just a stack of lumber that looks right. That changes how we specify framing members, clips, and straps, and it changes what the structural inspection checks. We build to the wind rating and keep the documentation with your permit file so you have it for insurance and resale. For a free estimate on a wind-rated Frisco ADU, call (877) 610-1318.
Yes, it can delay you, sometimes by weeks, if the submittal isn’t in order. Frisco’s master-planned communities run exterior elevations, window styles, brick color, and roof pitch through an architectural review committee. In the Panther Creek Estates neighborhood, an HOA committee took 11 days to approve an exterior elevation on one of our second-story additions. What keeps the schedule moving is permit-ready drawings that match HOA standards from the first submittal, not a redesign after the fact. That’s part of our standard process on Frisco projects.
Yes, it makes a real difference. When a Frisco addition is permitted, wind-rated, and documented with signed inspections, your insurance carrier has a paper trail showing the work met code when it was built. A job built without permits or engineered wind connections gives the carrier a reason to question the claim or the repair scope. That documentation lives in your permit file and in our records. It’s one of the concrete reasons we don’t skip permits, even when a cheaper bid says they’re optional. Call (877) 610-1318 and ask Tom about it directly.
A compliant quote includes third-party engineering, a permit package that clears Frisco’s plan review, wind-rated framing connections, HOA submittal drawings, and written change orders for every adjustment. A cheap quote leaves out the engineering, tells you permits are optional, skips the HOA approval, and frames to whatever passed in a neighboring city. Then the plan review flags it and you pay to redesign the job after the deposit was cashed. That’s the exact situation Tom designed Barrett & Sons to avoid. Call (877) 610-1318 for a written estimate with everything in line-item form.
Talk to Barrett & Sons About Your Frisco Home Addition or ADU
If you’re in Frisco and thinking about adding a room, a second story, or an ADU, call us before you sign anything. We’ll walk your project, check your lot’s soil, look up your HOA’s architectural standards, and give you a written estimate that includes the engineering and permits Frisco actually requires. A live person answers the phone 24/7 at (877) 610-1318. No voicemail box, no out-of-state call center. Just Tom or one of his sons, ready to talk.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Frisco since 1998.