Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across La Porte
A home addition in La Porte typically runs $45,000 to $130,000, while a new detached ADU lands between $90,000 and $220,000 and a garage conversion sits in the $30,000 to $80,000 range. Those numbers hold only if the contractor accounts for the two things that define this city: floodplain elevation rules and bay-salt corrosion. Most bids in La Porte move once crews open a wall and find out what the salt air has been doing to the framing for forty years. That’s exactly why our Home Additions & ADU team writes allowances into every contract before the first wall is opened.
Call (877) 610-1318 and Tom Barrett will walk your lot, look at the flood map, and give you a written line-item estimate for your La Porte addition or ADU. No phone-then-door price games.
Why Barrett & Sons Construction Is La Porte’s Preferred Home Additions & ADU Company
Founded in 1998 and owner-operated from day one, Barrett & Sons Construction is Tom Barrett with his name on the truck and his sons running the crews. When you call, a live person answers, 24/7. When you sign, Tom’s name, address, and license number are on the contract. When a change order comes, it arrives in writing before a single nail moves. That’s how we’ve worked for over 29 years, and it’s how we work in La Porte.
La Porte isn’t a generic suburb. The neighborhoods along Fairmont Parkway, around Bayshore Drive, and the older pockets off Spencer Highway carry different flood designations, different soil conditions, and different eras of construction. What works on a 1990s slab in Deer Park may not hold on a 1960s ranch in the 77571 ZIP. We’ve pulled permits here, argued plan reviews with the city, and stood next to the FEMA elevation certifier more times than we can count. Our Home Additions & ADU in La Porte work is built on that ground-level familiarity, not a generic playbook.
- Written change orders on every scope adjustment, every allowance, every unknown
- 90-Day Done Right Promise written on every contract: if it’s not right, Tom comes back, one call
- Permits pulled and inspections signed on every eligible job
- Background-checked crew members in Barrett & Sons uniform, not strangers off a van
Our Home Additions & ADU Services in La Porte
Opening up an older La Porte home usually turns up three things: outdated wiring with corroded terminations from bay humidity, undersized or damaged framing connectors that have lost section to salt, and waterproofing that’s quietly failed behind the siding. Any of these can move a quote, which is why we inspect first, write allowances into the contract, and price every surprise in writing before we touch it.
Room Additions
A room addition in La Porte means pouring new foundation adjacent to old, and that’s where the black clay soils under Harris County can cause differential heave. We recommend soil borings before the slab is designed, and we never pour a new-old connection without engineered piers where the soils call for it. Bedrooms, family rooms, in-law suites off the back of a ranch on Fairmont: we’ve built them all with permits signed and a foundation detail the inspector actually approves.

New Detached ADU
A detached ADU in La Porte is effectively ground-up construction, which means the FEMA Zone AE base flood elevation rules apply from the first footing. An elevation certificate often becomes part of the permitting package here, especially in the 77571 and 77572 ZIPs. We handle the ADU design, the floodplain compliance, the structural engineering, and the full build, supplying Simonton windows on many of our La Porte ADU installations because their coastal-rated lines stand up to bay conditions.

Garage Conversion ADU
Converting a garage in La Porte is the fastest path to an ADU, but the existing slab may not meet current living-space insulation, moisture-barrier, or elevation standards. On the west side near the Ship Channel industrial buffer, we’ve broken ground and found imported fill of unpredictable composition beneath the surface clay, a condition that makes soil borings a practical necessity before framing. We price the unknown honestly: an allowance in writing, not a surprise at the final draw.

Junior ADU & Interior Conversion
A junior ADU carved out of a 1970s La Porte home almost always triggers an electrical question: can the existing panel and branch circuits handle the new loads, or are you opening walls to find taped splices and corroded terminations that the bay air has been working on for fifty years? We answer that question with an inspection before we give you a fixed number, and when a whole-house wiring upgrade is required, you’ll see it as a line item, not a phone call at the end.

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.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in La Porte
We stock and install materials you can look up, not mystery brands off a van. On La Porte additions and ADUs, that means PGT and CGI impact-rated windows and doors, chosen for their coastal corrosion and storm performance, and Simonton windows where the project calls for a vinyl line that handles the Bay’s humidity. When you ask about a brand, we can tell you why we picked it for your lot, your exposure, and your flood zone. That’s the difference between a contractor who specs and a contractor who guesses.
Common Home Additions & ADU Problems We See in La Porte Homes
- Slab heave at the new-old connection. Harris County black clay expands and contracts with moisture, and a slab-on-grade addition without soil borings or engineered piers will crack at the seam where new concrete meets old. We’ve seen differential settlement cracks within two years on homes where a previous contractor skipped the borings.
- Salt-corroded framing connectors. Original 1960s-to-1990s framing connectors and fasteners near Galveston Bay lose section to salt air far faster than inland homes, and they can fail inspection sign-off after rough-in. We spec corrosion-resistant connectors and coated fasteners on every bay-exposed addition.
- Zone AE elevation triggers. Adding square footage without confirming FEMA base flood elevation can force expensive rework or a rejected elevation certificate before the punch list closes. On La Porte additions, the flood elevation conversation happens before the design, not after the slab is poured.
- Unpredictable substrate on the west side. Residential lots near the Ship Channel industrial buffer were historically raised with imported fill of inconsistent composition, and crews breaking ground in these areas regularly hit loose pockets beneath the surface clay. Soil borings before foundation work are not optional there.
Pricing for Home Additions & ADU in La Porte, TX
Here’s what La Porte homeowners can expect to pay for our work, as of this year:
| Project | Price Range |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
What moves the number: square footage, whether the lot sits in Zone AE and needs an elevation certificate, soil conditions on the west side, and what the walls reveal once they’re open. We handle those unknowns with written allowances and change orders before work proceeds. Call (877) 610-1318 for a free written line-item estimate on your La Porte addition or ADU. No trip charge inside the county.
We Also Serve Cities Near La Porte
Our crews work across the Bay Area and Ship Channel corridor. If you’re in Deer Park, Seabrook, Pasadena, or Baytown and you’re planning a room addition or ADU, the same Barrett & Sons standards apply: permits signed, change orders in writing, and Tom’s name on the contract. Home Additions & ADU in La Porte is where our local knowledge runs deepest, but the 90-Day Done Right Promise travels with us.
Serving La Porte, TX - Our Local Coverage Area
We’re based in the La Porte 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 La Porte
An addition to a pre-FIRM home in La Porte can trigger a requirement to document the structure’s base flood elevation, even when the original house predates the flood maps and is grandfathered. The city and FEMA look at the addition’s footprint and the proposed finished floor height, and in Zone AE, an elevation certificate often becomes part of the permitting package. We’ll tell you in the first meeting whether your specific lot and addition trigger the requirement, and we’ll handle the certifier if it does. Call (877) 610-1318 and ask Tom directly.
We spec galvanized or stainless steel connectors, coated fasteners, and corrosion-resistant flashing on any La Porte addition exposed to Galveston Bay’s salt-laden humidity. The standard hardware-store connector that lasts twenty years inland can lose section in a decade bayside, and we’re not rebuilding a connector on our dime because we skipped the upgrade. On west-side and bay-front jobs, the fastener schedule is written into the contract as a line item, not a suggestion.
We write a soil-boring allowance into the garage conversion contract up front, and we price the foundation detail once the borings come back. On the west side near the Ship Channel industrial buffer, imported fill of inconsistent composition under the surface clay is common enough that we treat soil borings as the starting point, not an add-on. Any foundation change that follows is a written change order you approve before we pour. Call (877) 610-1318 for a free estimate that includes the allowance.
Sometimes it will, and that’s not a scare tactic, it’s what the walls reveal. Homes built near the Bay before modern grounding and AFCI requirements often have corroded terminations and branch circuits that can’t legally carry the new ADU loads. If a whole-house panel or wiring upgrade is required, you’ll see it as a written change order with a fixed price before any wall is opened. That’s the rule on every Barrett & Sons La Porte job.
Yes, and we order it before design is finalized. The original slab was never engineered for the added weight of a second story, and Harris County’s black clay soils add differential movement into the mix. A structural engineer reviews the existing slab, the footings, and the soil report, and if the original foundation needs reinforcement, that’s a line item in your estimate, not a surprise at framing. Call (877) 610-1318 for an exact quote, and we’ll walk the existing slab with you on the first visit.
Planning an addition or ADU in La Porte means planning for floodplain rules, salt-air corrosion, and soils that can argue with your foundation. Our Home Additions & ADU team handles all three, in writing, before a single yard of concrete is poured. Call (877) 610-1318 to schedule your free estimate, and ask for Tom Barrett personally.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving La Porte and the surrounding Bay Area since 1998.







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