Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across The Woodlands
Home additions and ADU construction in The Woodlands typically run $45,000 to $130,000 for a room addition, and $90,000 to $220,000 for a full detached ADU, with garage conversions landing between $30,000 and $80,000. Those numbers reflect a community where deed restrictions, protected pines, and village Architectural Review Committees shape every foundation pour and roofline. If you’re weighing an addition against a move, call us at (877) 610-1318 and we’ll walk your lot with you before you sign anything.
The Woodlands is not like building in Conroe or Spring. The villages here operate under their own architectural review process, and the mature loblolly pines that give the community its character also put surface roots exactly where your addition wants to sit. We plan around that reality from the first site visit, because a builder who doesn’t know Grogan’s Mill from Alden Bridge will lose you three weeks on an arborist report before a single footing is dug.
Why Barrett & Sons Construction Is The Woodlands’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews. When you call about a second-story addition in Grogan’s Mill or a garage conversion in Panther Creek, the person who answers is someone whose name is on the truck. Every addition and ADU we build in The Woodlands goes through the village ARC process with permits pulled and inspections signed, because the last contractor most of our customers used told them permits were optional. Around here, they aren’t, and the village will catch it.
Our Home Additions & ADU team knows the villages. We’ve poured footings where mature pine roots had to be worked around, not cut. We know that Creekside Park homes tend to be newer semi-custom builds with tighter setback lines, while Grogan’s Mill and Panther Creek stock from the 1970s and 80s often sits on post-tension slabs that need an engineer’s eye before any addition ties in. That local knowledge is why homeowners across The Woodlands call us first. A live person answers 24 hours a day, seven days a week, not a voicemail box in another state.
Every job comes with the 90-Day Done Right Promise written on the contract. If something’s not right, Tom comes back and makes it right. One call. He lives twenty minutes away and wants to know about it.
Our Home Additions & ADU Services in The Woodlands
ADU Design & Permitting
Building an ADU in The Woodlands means navigating the village ARC, the Montgomery County permitting office, and the deed restrictions attached to your specific village. We handle the full design and permitting chain: site survey, arborist coordination when protected trees sit near the footprint, architectural drawings that respect the community’s forest-preservation character, and all ARC submittals. A new detached ADU in The Woodlands generally falls between $90,000 and $220,000 depending on square footage, foundation type, and utility runs.

Garage Conversion ADU
Converting an attached garage into living space is often the smartest dollar-per-square-foot move in older villages like Grogan’s Mill, where existing slabs and rooflines can be preserved. Garage conversions in The Woodlands typically run $30,000 to $80,000, and we coordinate the required elevation, drainage, and slab assessments that Montgomery County clay soils demand. Some villages restrict full garage conversions that reduce off-street parking below two spaces, so we verify deed language before you commit.

New Detached ADU
A ground-up detached ADU in The Woodlands gives you a separate address, a separate meter, and the option to rent it out or house family without sharing walls. These projects run $90,000 to $220,000 and are the most permit-heavy option on this page. We’ve built them in Alden Bridge and Creekside Park where larger lots accommodate a standalone structure, and we always pull water, sewer, and electrical as separate services rather than tapping the main house, which the county will flag on inspection.

Junior ADU & Interior Conversion
For homeowners who want a mother-in-law suite without a full building permit cycle, a junior ADU carved from existing square footage is the leanest path. We convert bonus rooms, oversized utility spaces, and attached sunrooms into permitted living quarters with their own kitchenette and entrance, typically landing in the $45,000 to $80,000 range in The Woodlands. The ARC still reviews exterior changes like a new door or window, and we handle that paperwork too.

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 The Woodlands
We don’t put mystery materials off a van into your addition or ADU. In The Woodlands we regularly install Schluter waterproofing systems in ADU wet areas, Sterling plumbing fixtures in junior suites, and GAF roofing on new detached structures that need to match the main house’s roofline. These are brands you can look up, with warranty paperwork you can hold. When we build an addition in The Woodlands, every finish brand is named in the contract, line by line, before we open a wall.
Common Home Additions & ADU Problems We See in The Woodlands Homes
- Protected pine roots conflicting with footings and flatwork. In Grogan’s Mill and Panther Creek, surface roots from deed-protected loblolly pines routinely run through proposed addition footprints. Getting a variance to remove even one tree can stall a project for weeks and requires a certified arborist report submitted to the village ARC, which out-of-area builders don’t anticipate.
- Slab heave on Montgomery County clay. The expansive clay soils across The Woodlands shrink and swell with wet-dry cycles, causing slab movement that must be evaluated before any addition ties into existing structure. We’ve seen 40-year-old post-tension slabs in Grogan’s Mill that an engineer had to sign off on before we could add a bedroom above them.
- Flood-remediation rebuilds from Hurricane Harvey. Lower-lying sections of The Woodlands took water in 2017, and many homeowners are still working through elevation-certificate-driven rebuild decisions. An addition on a home with a Harvey claim often needs updated elevation documentation before the county will release a permit.
- Village ARC design restrictions on addition massing. Each village in The Woodlands enforces its own architectural guidelines, and a second-story addition that flies in Creekside Park may be rejected in Grogan’s Mill for roofline proportions or window placement visible from the street. We’ve been through enough ARC reviews to know what passes before we draw it.
Pricing for Home Additions & ADU in The Woodlands, TX
Room additions in The Woodlands run $45,000 to $130,000, with garage conversions at $30,000 to $80,000 and new detached ADUs at $90,000 to $220,000. Junior ADUs and interior conversions land between $45,000 and $80,000. What moves the number: whether the addition ties into existing plumbing, whether protected trees sit inside or near the footprint, whether your village requires masonry or hardie plank to match existing elevations, and whether the slab needs engineering after 40 years of clay-soil movement. One thing we do differently: every allowance, every scope change, every price adjustment arrives as a written change order before work happens. No surprise invoice at the end. Call (877) 610-1318 for a line-item estimate and we’ll walk your lot together.
We Also Serve Cities Near The Woodlands
Beyond The Woodlands, our crews serve Spring, Tomball, Aldine, and Jersey Village. If you’re nearby and comparing addition or ADU bids, we’ll show you how our written-change-order process works. We’re also the team to call for Kitchen Remodeling in The Woodlands when your addition calls for moving the cooking wall, and Bathroom Remodeling in The Woodlands when the new primary suite needs a shower that actually drains. One team, one truck, one name.
Serving The Woodlands, TX - Our Local Coverage Area
We’re based in the The Woodlands 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 The Woodlands
We schedule site visits in The Woodlands within a few days of your call, not weeks. Since our crews work across The Woodlands regularly, we can often have Tom or one of his sons walk your property the same week you call (877) 610-1318. There’s no trip charge inside the county.
We work in every village: Grogan’s Mill, Panther Creek, Cochran’s Crossing, Alden Bridge, Sterling Ridge, Creekside Park, and Indian Springs, all within the 77381 ZIP code. Each village has its own ARC process, and we’ve submitted to all of them.
Yes, typically 10 to 20 percent higher, because village ARC review, arborist coordination for protected trees, and stricter material matching requirements add time and line items that don’t exist in unincorporated Montgomery County. A room addition that runs $45,000 in The Woodlands might run $38,000 to $40,000 just outside the township. The permit inspector works for you, not for me, and around here the village ARC adds a layer most builders never mention until the schedule slips.
Every addition and ADU we build in The Woodlands 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. Beyond that, every named brand we install carries its own manufacturer warranty, and we hand you the paperwork registered in your name.
Only if the scope changes, and only in writing. Every allowance, every change, every price adjustment arrives as a written change order you sign before we move. An allowance that isn’t on paper is a surprise waiting for a date, and we don’t build surprises into our The Woodlands jobs.
Ready to Plan Your Addition or ADU in The Woodlands?
If you’re weighing a room addition, garage conversion, or full detached ADU in The Woodlands, start with a free estimate and a walk of your property. We’ll tell you what the village ARC will flag, what your slab can carry, and what it honestly costs. Call (877) 610-1318 and ask for Tom. A live person answers, and the first visit is free.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving The Woodlands since 1998.







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