Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Dickinson
Adding square footage in Dickinson costs between $45,000 and $130,000 for a room addition, and $90,000 to $220,000 for a detached ADU. That’s the honest range we quote, because in 77539 the real variables aren’t the drywall or the roof trusses. They’re the elevation certificate, the black-clay soil under your slab, and whether Galveston County will sign off on your septic setbacks before we pour one foot of concrete. If you’re planning a home addition or ADU in Dickinson, call our team at (877) 610-1318. We’ve been owner-operated since 1998, and Tom Barrett’s name is on every contract.
Dickinson isn’t a place where you can hand a generic out-of-town crew a set of plans and hope for the best. Our Home Additions & ADU team has worked through the post-Harvey rebuild rules that still shape every structural decision here. We know what the county inspector is going to flag before he flags it, and we scope for it in writing before the first nail moves.
Why Barrett & Sons Construction Is Dickinson’s Preferred Home Additions & ADU Company
We’re a 29-year-old, owner-operated construction company, not a franchise dispatching strangers. Tom Barrett founded the business in 1998, and his sons run the crews that serve Dickinson. When you call, a live person answers, 24 hours a day. Not a voicemail box. Not an out-of-state call center. Tom publishes his name, his address, and his license number. Look it up before you sign anything.
Dickinson homeowners have a particular set of scars from contractors who quoted one price on the phone and handed over a different bill at the door. We handle pricing differently. Every scope, every allowance, every price change arrives as a written change order before work happens. “An allowance that isn’t on paper is a surprise waiting for a date.” We write that on every estimate we hand out in Dickinson.
We also back every job with the 90-Day Done Right Promise, written on the contract itself. If it’s not done right, one call brings Tom back. That’s not a marketing line. It’s the reason we can look a homeowner in the eye at the hardware store on FM 517 on Saturday and talk about the footing pour they watched us finish.
Our Home Additions & ADU Services in Dickinson
ADU Design & Permitting
Most Dickinson ADUs on acreage need both Galveston County building permits and, depending on water and sewer, county well and septic approval before framing begins. We handle the design, the elevation certificate, and the permit package as one scope. If your property drains toward Dickinson Bayou or a neighbor’s bayou-front lot, we document the sheet-flow plan early. County reviewers in Galveston County ask for that here more than in most places.

New Detached ADU
A detached ADU in Dickinson runs $90,000 to $220,000 depending on size, foundation method, and utility runs. On the black-clay soil common to this stretch of the Texas coast, we often recommend pier-and-beam or flood-vented stem wall foundations over a standard slab. That’s not an upsell. It’s what keeps the county elevation review off your back and your ADU from cracking at the corners after a dry summer.

Garage Conversion ADU
Converting an attached or detached garage in Dickinson runs $30,000 to $80,000. The wild card is the original slab. Many 1960s and 1970s garage slabs in Dickinson were poured thin, without vapor barriers, and they sit directly on expansive clay. We inspect for slab cracks and settling before quoting, and we’ll tell you honestly if the concrete needs to come out. You’ll know before you sign.

Junior ADU & Interior Conversion
A junior ADU, typically 400 to 700 square feet carved from an existing bedroom wing or oversized den, is the most economical way to add a rentable or in-law space in Dickinson. It keeps you inside the existing roofline, which sidesteps the largest flood-compliance reviews. Costs are often in the lower third of the $45,000 to $130,000 Home Addition range, though kitchenette plumbing and a separate entrance shape the final number.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
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 Dickinson
We don’t install mystery brands off a van. On windows and exterior-rated doors for Dickinson additions and ADUs, we install Simonton, Ply Gem, and PGT products, brands you can look up and see tested for Gulf Coast wind loads. For a sunroom or enclosed patio addition in Dickinson, the window spec matters: coastal wind ratings aren’t optional here, and PGT’s impact-rated line is the one we recommend most on bayou-facing lots. We order directly and schedule delivery around your inspection sequence, so materials aren’t sitting in your yard through a Gulf storm.
Common Home Additions & ADU Problems We See in Dickinson Homes
- Post-Harvey Substantial Damage letters complicate everything. If your home got a FEMA Substantial Damage determination after 2017, any addition that increases the footprint can trigger a full review of your elevation status. We prepare the elevation certificate and flood-vent detail before pulling the permit, so the review doesn’t become a stop-work order.
- Expansive black-clay soil cracks slabs and footings. Dickinson sits on soil that shrinks in dry summers and heaves after heavy rains. Additions that ignore this fail at the drywall joints within a few years. We scope piers, deeper footings, or reinforced stem walls depending on what the soil probe tells us.
- Septic and well setbacks on acreage surprise homeowners. A city lot in League City has different rules from a one-acre plot off Dickinson Avenue. On acreage, your ADU’s plumbing and foundation may need Galveston County health department approval for septic setback distances. We check that before quoting.
- Drainage from the new footprint redirects sheet flow. On open lots near Dickinson Bayou, adding a 600 sq ft structure changes where water goes. If the new roofline or slab edge points sheet flow toward a neighbor’s bayou-front parcel, the county will flag it. We grade and scope drainage at the start, not after the first hard rain.
Pricing for Home Additions & ADU in Dickinson, TX
Here’s what we quote in Dickinson, in writing, every time:
| Line Item | Dickinson Price Range |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
| ADU Site Prep & Utilities | $9,000-$28,000 |
What moves the number in Dickinson more than anything is the foundation method and the flood-compliance documentation. A room addition on a 1970s slab may need helical piers. A detached ADU on wet black-clay soil may need a pump truck and a flood-vented stem wall. Those aren’t extras we spring on you later. They’re line items in the first written estimate. We offer a free estimate, and we also honor a 10% Senior & Veteran discount on all work. Call (877) 610-1318 to schedule yours.
We Also Serve Cities Near Dickinson
Our crews serve Dickinson and the surrounding bay communities daily. If you’re in Bacliff, League City, Seabrook, or Webster, we pull the same permits, follow the same county rules, and bring the same written-change-order discipline to your job. The flood rules differ block by block along the bayou; we know which ones apply where.
Serving Dickinson, TX - Our Local Coverage Area
We’re based in the Dickinson 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 Dickinson
Most acreage in Dickinson’s 77539 zip code falls under Galveston County permitting authority for structural work, but any water, sewer, or septic connection triggers additional county health department review. A detached ADU typically requires both a building permit and either a sewer tap confirmation or a septic setback approval. We determine which permit package applies to your parcel before we quote. Call (877) 610-1318 and we’ll pull the records for your address.
You’ll need an elevation certificate and a flood-vented foundation detail submitted to Galveston County before any structural work begins. The Substantial Damage determination doesn’t go away when the drywall dries. Any addition that increases the home’s footprint or value can re-trigger the review, and the county will require documentation proving the finished structure meets current Base Flood Elevation standards. We handle that paperwork as part of our scope. Call (877) 610-1318 for a straight answer on your specific letter.
Because most original Dickinson slabs from the 1960s through the 1990s were poured before modern soil-compaction and vapor-barrier standards reached Galveston County, and the expansive black clay beneath them has been shrinking and heaving for 40 to 60 years. A new addition on a fresh slab next to a settled original slab creates a differential settlement problem. We often scope piers near the transition line or match the addition’s foundation type to what’s actually there, not what the old plans say. Get the free estimate at (877) 610-1318.
No, not on acreage in Dickinson. If your septic system was sized for a three-bedroom house, adding a kitchen and bathroom in a converted garage changes the county’s required tank and drain field calculations. Galveston County health department will ask for the septic sizing sheet. We check that before quoting your garage conversion. Call (877) 610-1318 to start the site review.
We walk the lot first. We look at the existing grade, the direction water moves during a hard rain, the proximity to Dickinson Bayou or any drainage ditch, and the soil condition at the build site. Then we write a fixed drainage and grading allowance into the estimate, including any swales, culverts, or French drains the county will require. You see that number before you sign, and it doesn’t change without a written change order. Estimates are free; call (877) 610-1318.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Dickinson and Galveston County since 1998.







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