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 Keene
A room addition on a Keene home typically runs $45,000 to $130,000, while a detached ADU lands between $90,000 and $220,000. The number moves depending on what hides behind the walls of your specific house, and in Keene, that matters more than in most towns. This is a city of mid-century homes near Southwestern Adventist University mixed with newer suburban tract builds, and the older stock has a habit of revealing wiring, framing, and waterproofing surprises the moment a wall comes down. We’ve been opening those walls since 1998, and we know what a permit inspector in Johnson County will and won’t sign off on. Call us at (877) 610-1318 and we’ll walk your property before you commit to a single line item.
Why Barrett & Sons Construction Is Keene’s Preferred Home Additions & ADU Company
We’re the owner-on-the-truck crew serving Keene, and Tom Barrett’s name, address, and license number are published for anyone to verify before signing a contract. That transparency matters in a town where word travels through the university community faster than most places. We understand that a significant share of Keene residents observe the Sabbath from Friday sundown to Saturday sundown and will not conduct business or permit job-site work during that window. So we schedule consultations, deliveries, and crews strictly Sunday through Friday, and we never send a crew out to a Keene property on a Saturday morning expecting to start demo. That one scheduling habit has earned us repeat referrals from families near campus who’ve watched out-of-town outfits lose jobs over the same mistake.
Our Home Additions & ADU work across Keene is backed by the 90-Day Done Right Promise, written on every contract: if it’s not done right, Tom comes back and makes it right with one call. Every scope, every allowance, and every price change arrives as a written change order before work proceeds, so the number you sign is the number you pay unless you approve something in writing first. That’s not a pitch; it’s how we’ve stayed busy for 29 years without a surprise-invoice reputation.
Our Home Additions & ADU Services in Keene
ADU Design & Permitting
Before a single footing is poured, we handle the design and the permit path for your accessory dwelling unit. In Keene, that means working with Johnson County’s permitting office and sitting in on every inspection. The permit is non-negotiable on these jobs, and we won’t cut that corner to save you a few hundred dollars. When an inspector signs off, you know the ADU meets code, not just our opinion.
New Detached ADU
A detached ADU in Keene starts at $90,000 and can reach $220,000 depending on square footage, finishes, and what the soil report says. Keene sits on Blackland Prairie clay that heaves during wet winters and shrinks through dry summers, so we order a soil report before we design the foundation. Skip that step and you’re gambling on a cracked slab within two wet winters. We pour for the soil you actually have, not the soil a national franchise assumes you have.
Garage Conversion ADU
Converting an existing garage into living space runs $30,000 to $80,000 in Keene. The work includes insulation, electrical, plumbing if you’re adding a Bathroom Remodeling in Keene or kitchenette, and bringing the whole structure up to current code. One warning from years of doing this in Keene: if your garage was built before the 1980s, plan on the electrical panel needing an upgrade. We write that allowance into the contract upfront so the change order, if it comes, is a formality, not a shock.
Junior ADU & Interior Conversion
When the addition is inside the existing footprint, a junior ADU or interior conversion often makes more sense than a full detached build. These projects are how Keene homeowners turn a bonus room, a finished attic, or a large bedroom into a private suite with its own entrance and kitchenette. The price depends on what’s already behind the walls, and in older homes near the university campus, that’s exactly where the surprises live.
What happens when you call
- 1
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 Keene
We install materials you can look up, not mystery brands off a van. On Keene additions and ADUs, that means Schluter waterproofing systems in wet areas, GAF Keene Roofing on any new rooflines, and Sterling fixtures where plumbing is part of the scope. When a brand has a warranty, we register it in your name and stand behind the installation with our own written promise. If a part fails inside the warranty window, we’re the ones who come back, not a call center.
Common Home Additions & ADU Problems We See in Keene Homes
- Expansive clay foundation movement. Keene’s Blackland Prairie soil swells and shrinks with the seasons, and an addition that doesn’t account for that movement will crack where the new foundation meets the old one. We engineer the joint properly and grade drainage away from the new build.
- Outdated wiring behind mid-century walls. Homes clustered near Southwestern Adventist University often still carry knob-and-tube or aluminum wiring. Opening a wall for an addition triggers an electrical code review, and that review usually requires panel and circuit upgrades before an inspector will sign.
- Undersized framing in original construction. Some of Keene’s older homes were framed with lumber that doesn’t meet current span tables. When we open a wall or ceiling for an addition, the inspector checks the existing structure, not just the new work. We plan for that in the scope.
- Failed waterproofing in original wet areas. When an addition ties into an older home, we often find the original tub surround or shower has been leaking into the framing for years. That’s a five-figure fix if nobody planned for it, and it’s exactly why we write allowances into the contract before the first wall comes down.
Here’s a specific example from Keene. On a room addition off a pier-and-beam home near campus, we opened the exterior wall and found knob-and-tube wiring still live behind the sheathing. Our scope of work already had a line item for electrical rough-in, but the inspector required a full panel replacement before sign-off. We priced the change order, got written approval, and pulled the new circuit through the subfloor. The room passed final inspection the first time. That’s how a Keene addition should go: no yelling, no surprises, no wall left open while someone figures out who pays for what.
Pricing for Home Additions & ADU in Keene, TX
Here’s what Keene homeowners can expect on the three most common projects we build in 76059.
| Project | Typical Keene Range |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
Your final number moves on square footage, finish level, site access, and what the soil and the existing structure require. We give you a written line-item quote before you sign anything, and every allowance is spelled out in the contract. If a surprise appears when we open a wall, you’ll see the price in writing and approve it before we proceed. No change order, no work. Call (877) 610-1318 to schedule a free estimate at your Keene property.
We Also Serve Cities Near Keene
Our crews work throughout Johnson County and the southern DFW edge. In addition to Keene, we serve Home Additions & ADU in Keene neighbors in Cleburne, Joshua, Burleson, and Crowley. Dispatch and scheduling coordinate from our Dallas-Fort Worth office, and the crews that show up are local, background-checked, and answer to Tom Barrett by name.
Serving Keene, TX - Our Local Coverage Area
We’re based in the Keene 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 Keene
The biggest cost driver is hidden conditions behind the walls: outdated wiring, undersized framing, and failed waterproofing that code upgrades force you to address before an inspector will sign off. On a 1960s Keene home near campus, a panel upgrade can add $3,000 to $6,000, and reframing an undersized header can add $2,000 to $5,000, before you ever get to drywall. We write allowances into the contract for exactly these conditions, so you know the ceiling on each line item before demo starts. Call (877) 610-1318 for a written quote on your specific home.
Yes, and on Keene’s Blackland Prairie clay, pier-and-beam is often the right call for a detached ADU, especially on lots with existing trees or drainage constraints. A pier-and-beam ADU in Keene runs $90,000 to $220,000 depending on size and finish, and the piers let you adjust for soil movement more cleanly than a monolithic slab. We order a soil report first and design the pier depth to match what’s actually under your lot. Call (877) 610-1318 to have us look at your site.
We schedule all Keene work Sunday through Friday, and we never send a crew to a Keene property on Saturday. If you observe the Sabbath from Friday sundown to Saturday sundown, we’ll plan deliveries, inspections, and noisy work accordingly, and we’ll confirm the schedule with you in writing before the project starts. It’s not a policy we advertise; it’s just how we’ve worked in this town for years. Call (877) 610-1318 and tell us your scheduling needs.
Yes, every garage conversion we do in Keene includes permits pulled and inspections signed. A garage conversion changes the use of the structure from storage to living space, and a third-party inspector must verify the electrical, insulation, egress, and structural work before the walls close. We won’t do the job without the permit, because the inspector works for you, not for me, and that’s exactly why I like him. Call (877) 610-1318 to walk through what your conversion will require.
It means every unknown condition has a pre-agreed price range before we start. If we open your wall and find live knob-and-tube wiring, the allowance for electrical upgrades is already in your contract, so you know what the fix costs and you approve the change order in writing before we proceed. An allowance that isn’t on paper is a surprise waiting for a date, and we don’t do surprises. Call (877) 610-1318 for a contract that spells out exactly what you’re signing.
Call Barrett & Sons Construction in Keene
If you’re planning a room addition, a garage conversion, or a detached ADU in Keene, call us at (877) 610-1318 to schedule your free estimate. We’ll walk the property, talk about what your specific home will need, and put the numbers in writing. No pressure, no Saturday surprises, no national-franchise phone maze. Just Tom’s crew, a written scope, and a permit on the wall.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Keene and Johnson County since 1998.