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Home Additions & Room Conversions in Clear Lake & League City, TX

We Take On the Additions Most Contractors Talk Themselves Out Of

  • Serving Clear Lake, League City & Galveston County Since 2009
  • $2,500 Pre-Construction CAD & Engineering Package
  • 10% Down to Start, Fixed-Price Proposals
  • 1-Year / 2-Year / 6-Year Warranty

The Risk Isn't the Addition. It's Not Knowing What You're Walking Into.

Bright attic living room with sloped walls, centered French doors flanked by white built‑in bookshelves, a desk and chair to the left, and a beige sofa with a coffee table to the right under recessed ceiling lights.

What You Want

What you want from an addition is simple. The number you agree to on day one is the number you pay at the end.

Most of that gets settled before anyone swings a hammer. The permit is pulled. An engineer draws the load path, the route the weight of the new roof takes down to the ground. Every finish is picked while a change still costs a new drawing. Then month four is quiet. You spend it watching the room take shape instead of asking what it costs now.

How We Deliver

Before you sign a construction contract, our $2,500 pre-construction agreement gets you 3D renderings, engineered floor plans, and a fully documented scope. You see the finished space and a fixed price before you’re financially committed, not after.

What You Want

The best compliment an addition can get is that nobody notices it. The brick matches. The new roofline ties into the old one so the ridge reads as a single line. The siding is the same shade, not a shade off.

Everyone has seen a car with one repainted fender, and it’s the only thing you look at afterward. Houses work the same way. When the details line up, the addition stops being an addition and becomes part of the house you live in.

How We Deliver

We match brick color and pattern, siding profile, roof pitch, and shingle, trim details, and window styles to your existing home. We engineer the foundation and roof tie-in for Clear Lake and League City’s expansive clay soils before we ever pour concrete.

Brick two-story house with large basement-style windows, a sloped roof, and a neatly landscaped foreground with green shrubs.
Home office with a curved desk and multiple monitors showing landscape images, a keyboard and pens in view, and a mesh office chair nearby.

What You Want

If you refinanced between 2020 and 2022, you locked in something worth keeping. A rate under 3.5% is an asset, and it stays yours for as long as that loan does.

Adding on is how you keep it and still get the space. Moving means trading it for something near 7%, which can run $1,500 to $3,000 more a month for the same square footage. That’s a second car payment on top of your first, for rooms you already own the land to build.

How We Deliver

An addition lets you keep your rate and get the space in the house you already chose. What you want underneath that is a room your insurer treats as part of the home. So we do the structural and windstorm engineering in house, during design, before anything gets framed.

 

Every addition meets Texas Windstorm Insurance Association standards and is documented through WPI-8, which is what your insurer asks for when they write the policy. In flood-mapped areas we set your floor above base flood elevation, because that height is the one thing you cannot change once the slab is poured.

Additions & Conversions We've Built Around the Bay Area

Explore some of our favorite additions, conversions, and outdoor living spaces we've completed for homeowners across Clear Lake, League City, and Houston.

Every Addition Runs Through the Same Five Stages, Starting With Mark

No guessing at what happens next. Here's the exact path from first call to final walkthrough.

Discovery Call

We start with a call to understand your goals, share a ballpark, and confirm we're the right fit before anyone comes out to the house.

In-Home Site Visit With Mark

Mark walks the space with you and talks through what's structurally possible — roof pitch, load paths, foundation, setbacks, flood zone, HOA — and refines your ballpark on the spot.

Pre-Construction Agreement

For $2,500 (adjusted for square footage), we produce CAD as-built and proposed floor plans, 3D renderings, engineered structural plans, elevation certificate coordination where needed, and a detailed scope. You see the finished space before committing to a number.

Engineered Plans, Fixed Price & Permitting

We finalize engineering, submit permits, walk you through fixed pricing and phasing, and introduce the trade partners who'll be working on your project.

Construction Contract & Build

10% down, weekly written updates, and JobTread portal access to your live schedule, budget, and daily logs — with dedicated project coordination through foundation, framing, roof tie-in, exterior match, mechanical, and interior finish-out.

What Does a Home Addition Cost in the Houston Bay Area?

Pricing depends on whether you're converting existing space or building on a new foundation, and every addition gets a fixed price after our pre-construction design phase, not before.

Standard — Conversions

Starting at

$65,000

Converting existing space within your home, including garage-to-gym or garage-to-living-space conversions, attic build-outs, and flex-room conversions. Best for growing families who need conditioned, usable space without expanding the foundation.

What's included

Deluxe — Single-Room Additions

Starting at

$135,000

A true addition on a new foundation, including home offices, bedrooms, or family-room additions, intentionally engineered for Houston’s expansive clay soils and tied correctly into your existing roof and structure. Best for homeowners who’ve outgrown the footprint.

What's included

Premium — Primary Suites & Multi-Room Additions

Typically

$225,000

Primary suite additions with a full bath, multi-room additions, and second-story additions — including FEMA Base Flood Elevation design for coastal properties, foundation systems engineered for the load, and 3D renderings of the finished result before we break ground. Best for the “we love this home and this street — we just need more of it” family.

What's included

Every tier starts with the same $2,500 pre-construction agreement, so you see engineered plans and a fixed price before committing to a final number.

The Republic Difference

Our promises to the homeowners of the Greater Houston Area.

3D CAD Drawings Before You Sign a Full Contract

A $2,500 pre-construction agreement includes your initial site visit, in-house 3D CAD drawings, and engineered floor plans before you commit to construction. One family we worked with said the CAD drawings showed them more space than they'd originally imagined — that's just one benefit of seeing the finished project before it's built.

One Fixed Price, Set Before Construction Starts

Our proposals are fixed-price, not cost-plus, so the number in your contract is the number you pay. Once you approve the plan, a modest 10% down payment moves your project forward.

Permits, Engineering Seals, and Coastal Codes, Handled In-House

We manage full permit navigation with the City of Webster, including asbestos surveys and engineering seals. Our builds meet Gulf Coast standards — wind-rated glass, flood-resistant materials, hurricane-resistant roofing — for homes across Galveston County and coastal Harris County. Every project carries a one-year workmanship, two-year systems, and six-year structural warranty through ACES Builders' Warranty.

Common Home Addition Questions From Our Clients

How long does a home addition take from first call to completion?

Our initial conversation and design phase typically takes a few weeks, and construction runs 8–12 weeks for a conversion, 3–5 months for a single-room addition, or 5–8 months for a primary suite or multi-room addition, depending on scope.

In most cases, yes. We frame, dry-in, and roof the addition before opening the connecting wall to your existing home, and we use zip-wall dust containment and floor protection to keep your living space sealed and functional for as long as possible.

We match brick color and pattern, siding profile, roof pitch and shingle, trim details, and window styles to the existing house, so the finished addition fits seamlessly into the existing exterior.

Our pricing is fixed. After the $2,500 pre-construction agreement produces engineered plans and a documented scope, we give you a fixed-price proposal so you know what you’re paying before the construction begins.

We provide a 1-year warranty on general workmanship, 2 years on HVAC, electrical, and plumbing, and 6 years on anything structural, all backed by a third-party warranty company.

Hear From the People We've Built For

Don't just take our word for it. Honest words from the families whose homes we've helped transform.

Feeling Ready to Expand?

Let's talk through what's possible on your lot, your budget, and your timeline.