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 Cinco Ranch
Adding square footage in Cinco Ranch usually costs between $45,000 and $130,000 for a room addition or garage conversion, and $90,000 to $220,000 for a new detached ADU. If your project also needs Cinco Ranch Roofing work, we’ll bundle that into the same scope and timeline. Those numbers come from the actual bids we’ve written for homeowners along Westheimer Parkway, Peek Road, and the subdivisions feeding Cinco Ranch High School. If you’re planning a mother-in-law suite near LaCenterra or a second story over an original 2005 Newmark home, we’ll walk the property, check the slab, and give you a written line-item quote before anything moves. Call (877) 610-1318 and we’ll come out at no charge inside the county.
Why Barrett & Sons Construction Is Cinco Ranch’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews that show up in Cinco Ranch. That matters because the person who shakes your hand is the person who’ll answer when you call about a crack in the new drywall six months after the job’s done. Cinco Ranch homeowners tell us the same story again and again: a national outfit quoted one number over the phone, then handed over a change order with a different number after the slab was opened. We don’t work that way. Every allowance, every scope, every price change is a written change order issued before a single nail moves. Tom lives twenty minutes away; if something’s not right, he wants to know about it, and the 90-Day Done Right Promise puts that in writing.
We know what the HOA architectural control committees in Cinco Ranch require, because we’ve sat through those submittals. We know the flood zone maps changed after Harvey, and we know which lots need first-floor elevation adjustments before an addition can be permitted. We’ve pulled permits on hundreds of jobs across Fort Bend County and stood with homeowners while the inspector signed off. Tom publishes his name, address, and license number. Look him up before you sign anything.
Our Home Additions & ADU Services in Cinco Ranch
ADU Design & Permitting
Cinco Ranch’s post-tension slabs don’t forgive guesswork. When we design an ADU for a backyard off Gaston Road or a side yard in the neighborhoods behind the Cinco Ranch public library, we start with foundation analysis, not a blueprint. Katy Prairie black clay expands and contracts with every wet-dry cycle, so a detached unit needs soil-stabilized site prep. We handle the ACC pre-approval submittal, the building permits, the drainage plan, and the inspections, so you’re not chasing the county yourself.
Garage Conversion ADU
A garage conversion in Cinco Ranch typically runs $30,000 to $80,000, depending on whether we’re adding a bathroom, a kitchenette, and a separate entrance. Most of the garages here were built as part of the original 1995-2015 phased construction, which means the slab was poured as a single post-tension unit. Cutting into it for plumbing requires an engineer’s sign-off, and we don’t skip that step. We’ll also match the brick veneer on the front elevation so the HOA doesn’t flag the finished work.
New Detached ADU
Building a new detached ADU in Cinco Ranch means starting from bare Katy Prairie soil, and that’s where most out-of-area contractors get it wrong. We bring the lot grade up where the FEMA maps demand it, install French drains so the clay doesn’t saturate against the new slab edge, and pour footings sized for the shrink-swell cycle. Budget $90,000 to $220,000 for a complete one-bedroom unit with a kitchen, bath, and its own HVAC.
Junior ADU & Interior Conversion
Not every Cinco Ranch family needs a full detached unit. A junior ADU built inside the existing footprint, like a bedroom suite over the garage or a converted bonus room above the original family room, often costs $45,000 to $90,000. It uses the home’s systems, shares the roof, and keeps the exterior footprint unchanged, which means a simpler ACC process. We’ve done these for aging parents in the neighborhoods south of Cinco Ranch Boulevard and for adult children returning to Fort Bend County.
If you’re already planning a larger interior change, our Home Additions & ADU team coordinates with the same crews who handle whole-room work, so one contract covers the addition and the finishes. And when your family’s needs touch the original kitchen or primary bath, we also handle Kitchen Remodeling in Cinco Ranch and Bathroom Remodeling in Cinco Ranch under the same roof.
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 Cinco Ranch
We don’t put mystery materials in a Cinco Ranch addition. For wet areas we spec Schluter waterproofing systems, and for fixtures we lean on Grohe and Sterling because they hold up to the humidity cycles this part of Texas throws at a bathroom. If you have an existing brand you want matched, we’ll source it. If you want the HOA-approved materials list met without a fight, we’ll spec it accordingly. No off-brand substitutes, and every material choice appears in writing before we order it.
Common Home Additions & ADU Problems We See in Cinco Ranch Homes
- Slab movement under new work. The black clay under Cinco Ranch swells after a wet spring and shrinks in an August drought. A new addition tied to an existing post-tension slab needs engineered joints and moisture-managed site prep, or you’ll see a step crack at the connection within two years.
- HOA submittal rejections. Cinco Ranch’s architectural control committees are among the most active in the Houston metro. Missing a materials spec or color palette on the pre-approval form means a failed review and a delayed start. We file the submittal to match the committee’s checklist.
- Flood zone elevation surprises. After Hurricane Harvey, FEMA reclassified parts of Cinco Ranch into higher-risk zones. A permitted addition on one of those lots may need the first floor raised or the drainage plan re-engineered. We find that out during design, not after the foundation crew shows up.
- Undersized HVAC for the added square footage. The original 1995-2015 split systems weren’t sized for a 400-square-foot addition. Running the existing air handler into new space leaves the back bedrooms hot in July. We calculate the added load and spec a zone damper or a dedicated mini-split.
Pricing for Home Additions & ADU in Cinco Ranch, TX
A room addition in Cinco Ranch runs $45,000 to $130,000. A detached ADU starts around $90,000 and can reach $220,000 for a fully finished one-bedroom unit with premium fixtures. A garage conversion lands between $30,000 and $80,000. What moves the number? Foundation work and soil prep are the biggest variables on Katy Prairie clay, followed by whether the HOA requires exterior materials that match the original brick or stone. Permits and inspections are included in our quote. The written change order system means the number we give you is the number you pay, unless you change the scope and approve the change in writing first. Call (877) 610-1318 and we’ll give you a free, line-item estimate for your specific lot.
We Also Serve Cities Near Cinco Ranch
Our crews work across Fort Bend and western Harris County, and we regularly build additions for homeowners in Pecan Grove, Four Corners, Mission Bend, and Alief. If you’re a few minutes outside the 77450 zip and wondering whether we’ll come out, the answer is yes. Our Cinco Ranch clients get the same written-scope process as everyone else we serve, and the trip charge is waived inside the county.
Serving Cinco Ranch, TX - Our Local Coverage Area
We’re based in the Cinco Ranch 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 Cinco Ranch
Expect $45,000 to $130,000 for a room addition and $90,000 to $220,000 for a new detached ADU on a typical Cinco Ranch lot. The range depends on soil prep, flood zone elevation requirements, HOA materials approval, and whether you’re tying into existing plumbing and HVAC. Call (877) 610-1318 for a written line-item quote specific to your property, with no trip charge inside Fort Bend County.
Yes. Every eligible job includes permits pulled and inspections signed. Cinco Ranch sits in Fort Bend County, where unpermitted additions get flagged at resale and can void your coverage if a structural issue appears. The permit inspector works for you, not for us, and we like having him on the job. We handle the full permit file, the ACC submittal, and the final inspection sign-off.
Most likely, if the submittal includes the materials specs, color palette, and elevations the architectural control committee asks for. We’ve worked with Cinco Ranch ACC committees on garage conversions, second-story additions, and detached units, and we know which details they flag first. We file the complete pre-approval package before we break ground, so you’re not paying for a crew that’s waiting on committee feedback.
A garage conversion typically runs 8 to 12 weeks, a room addition 10 to 16 weeks, and a detached ADU 4 to 7 months from lot prep to final inspection. HOA review cycles, flood zone plan checks, and the wet season can stretch the schedule. We give you a written timeline at contract signing and update it by change order if a scope change alters it. Call (877) 610-1318 for an honest schedule for your project.
The 90-Day Done Right Promise is written on every contract, not buried in fine print. If something’s not done right during the first 90 days after completion, Tom Barrett comes back and makes it right with one call. That covers workmanship corrections on the addition or ADU. Material warranties from manufacturers like Schluter and Grohe run separately and longer. We don’t hide behind sub-contractor blame; Tom’s sons run the crews, and the name on the truck is the name that answers the phone.
Get Your Free Cinco Ranch Addition Estimate
Planning an ADU near Westheimer Parkway, a garage conversion off Peek Road, or a second story in one of the original Newmark subdivisions? Call (877) 610-1318 and we’ll set a time to walk the property, check the slab, and talk through what the HOA and county will want to see. The estimate is free, the numbers are in writing, and we’ll tell you honestly if your lot has flood zone or soil conditions that need extra engineering before you spend a dollar on plans.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Cinco Ranch and surrounding Fort Bend County communities since 1998.