







Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Ameristar Home Additions & ADU: The Fort Worth Owner’s Guide
If you’re searching for an Ameristar home addition or ADU in Fort Worth, you’re likely weighing a garage conversion, a bump-out, or a full second structure on your property. A complete addition or ADU project in Fort Worth typically runs $45,000 – $130,000 depending on scope, foundation work, and finish level, while a detached ADU runs higher at $90,000 – $220,000. We’re Sawyer Remodel Fort Worth, and we handle Ameristar-compatible addition and ADU work from permit drawings to final walkthroughs. If your current space isn’t working and you’re in Fort Worth, the most common discovery is the same: the house works fine, but the floor plan doesn’t.
Quick note before we go further: Sawyer Remodel Fort Worth is an independent remodeling company. We’re not affiliated with Ameristar, but we work with their product lines and build additions and ADUs that integrate with existing Ameristar structures and finish packages.
Which Ameristar Models This Applies To

Ameristar’s residential additions and ADU offerings fall into a few broad categories, and the planning path differs for each:
- Attached additions (bedroom suites, family room bump-outs, second-story additions) that tie into the existing roof line and foundation.
- Detached ADUs (accessory dwelling units) built as standalone structures, typically 400 – 1,200 square feet in Fort Worth zoning.
- Garage conversions where the Ameristar-framed garage becomes living space, usually $30,000 – $80,000 in Fort Worth.
The compatibility question isn’t about a part number the way it is with a water heater or furnace. It’s about roof pitch matching, foundation type (slab vs. pier-and-beam), and siding profile. An Ameristar addition needs the framing to marry correctly to the existing structure, and the trim lines need to match so the new section doesn’t look bolted on. The gotcha we see in Fort Worth: older Ameristar builds used 2×4 exterior wall framing, while current code here requires 2×6 for energy compliance. That changes the window jamb depth, the siding reveal, and the interior shelf reveals. If you’re planning an addition on a pre-2010 Ameristar home, budget for furring and transition trim at the tie-in points.
For the material decision: Ameristar OEM trim, corner posts, and siding profiles are still available for most models. Quality aftermarket equivalents from James Hardie often match or exceed the original spec, and that’s usually what we recommend for durability in Texas sun and hail. You get the same profile, better impact resistance, and a real manufacturer warranty behind the install.
Styles & brands we work with







Signs Your Ameristar Home Addition or ADU Is Failing
Additions don’t “fail” overnight the way a motor does. They fail slowly, and by the time it’s obvious, the fix is usually bigger. Here’s what we see on Ameristar structures in Fort Worth:
- Separation at the tie-in seam. Caulk lines crack and open where the addition meets the original house. The cause: different foundation movement between the original slab and the new footing, or framing that settled differently after construction.
- Sloped floors in the addition. A visible slope more than 1/4 inch per foot suggests the concrete pad or pier spacing wasn’t spec’d for the room loading. This is a structural problem, not a finish problem.
- Water staining on the ceiling where roof lines meet. The valley flashing at the roof tie-in is the first thing to fail on an attached addition. In Fort Worth, a 50-year asphalt shingle valley that wasn’t installed with proper ice-and-water shield will leak inside 10 years.
- Doors and windows sticking only in the new section. Frames racked during settling. If the original house is square and the addition isn’t, that’s a framing or foundation correction, not a hardware adjustment.
- Drywall cracking in the upper corners of the addition walls. Truss uplift or thermal expansion of the roof structure. Common in Fort Worth where summer attic temps hit 140°F and winter nights drop below freezing.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included

In Fort Worth, a full addition to a home lands between $45,000 and $130,000. A detached ADU runs $90,000 – $220,000. A garage conversion sits at $30,000 – $80,000. What drives the range is the foundation type (slab is cheaper than pier-and-beam corrections), whether plumbing is wet (bath/kitchen) or dry (bedroom/home office), and the finish level inside. A bare-bones 400-square-foot ADU with one bathroom is very different from a 900-square-foot two-bedroom unit with a kitchen.
What’s included when we build: permits, plans and engineering, foundation, framing, roofing, siding, electrical, plumbing rough-in, insulation, drywall, paint, and the finish carpentry. We don’t bury line items in change orders. The written price you approve before we start is the number on the invoice. If we hit something hidden during demo, we tell you the cost before we touch it. That’s the Relay Visibility Guarantee, and it applies to every project, no exceptions.
DIY or Call Us?
Here’s the honest split. You can research zoning, check your lot size, and sketch out what you want. You can pull the Fort Worth permit requirements online. What you shouldn’t do is frame a second-story addition, tie into an existing roof line, or pour a foundation without a professional. Get the load path wrong and you’re looking at a structural failure. Get the waterproofing wrong and you’ve got a mold problem inside a year.
The dangerous work is the structural work: cutting roof trusses, altering load-bearing walls, and excavating for footings. That’s not a weekend project, and it’s not something to learn from a video. If you’re in Fort Worth and thinking about an addition or ADU, call us at (682) 841-6652. I’ll walk the property with you and tell you what’s actually buildable and what it’ll actually cost.
FAQs

A properly built addition or ADU in Fort Worth should last 50+ years structurally, with finish work needing refresh every 10 – 15 years. The limiting factors in our climate are heat, UV, and occasional hail, which wear roofing and siding faster than the framing beneath them. Insulation performance and HVAC sizing matter more here than in most markets because of 100°F summer peaks. Call (682) 841-6652 if you want a straight answer on your existing structure’s remaining life.
Yes, in most cases. Tie-in flashing failures, settling cracks, and water intrusion are repairable at a fraction of the cost of rebuilding. The exceptions are when foundation movement is severe enough to compromise walls or when the original framing was undersized. We’ll tell you which situation you have, and we won’t recommend a rebuild if a repair is the right call. Estimates are free.
A typical single-room addition takes 8 – 12 weeks from permit to final walkthrough. A detached ADU runs 12 – 20 weeks depending on size, utility runs, and weather. Permitting in Fort Worth usually takes 3 – 6 weeks, and that’s built into the schedule we give you before work starts.
Yes. We match existing Ameristar siding profiles, trim lines, interior door styles, and paint schemes so the new section looks like part of the original home. We stock common Fort Worth-matched profiles and can source Ameristar OEM or James Hardie aftermarket equivalents for any model we encounter. Call (682) 841-6652 and tell us what you’ve got.
Written by Luca Romano, Owner & Lead Remodeler, Sawyer Remodel Fort Worth, serving Fort Worth and nearby areas.


