Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
PGT Home Additions & ADU: The San Antonio Owner's Guide
PGT home additions and ADU projects in San Antonio typically run $45,000 – $130,000 for a full addition and $90,000 – $220,000 for a detached accessory dwelling unit, with permits and foundation work included in the written price we give you before any work starts. If you’re reading this, you’re probably standing in a house that doesn’t quite fit anymore, or you’ve got an aging PGT addition that’s showing its years and you need a honest answer about what it’ll cost to fix or expand. The failure pattern we see most often in this part of Texas isn’t a sudden collapse, it’s the slow stuff: hairline cracks at the addition-to-house seam, door frames that won’t close square after a dry summer, and PGT window or door openings that have drifted out of level because the original pier work wasn’t done for our clay soil.
Which PGT Models This Applies To
If your San Antonio home carries PGT windows or doors, and you’re adding a room, a wing, or a detached ADU, the compatibility question is about more than matching the glass. PGT’s product lines split into two worlds: their impact-rated products built for coastal wind zones, and their standard architectural series. Both can be matched in a new addition, but here’s the gotcha we run into on jobs around San Antonio: a PGT impact window from a 2015 build will not always have the same frame depth as a current-model PGT unit, even in what looks like the same series. The label is on the inside of the frame, on the sash or the head jamb, and it’ll show the series, the glass package, and the size. When we extend an existing room that has PGT windows, we take frame-depth measurements before anything is ordered, because a quarter-inch difference changes how the new drywall returns meet the existing trim. For ADUs, an aftermarket window that matches the look but not the frame spec will show itself within the first year, and that’s a callback nobody wants. OEM is the safe path when the addition shares a wall with existing PGT openings; on a fully detached ADU, a quality aftermarket match can save real money without compromising the seal.
Styles & brands we work with
Signs Your PGT Home Additions & ADU Is Failing
- Cracking at the seam where the addition meets the main house. This is the most common call we get after a dry San Antonio summer. Clay soil shrinks, the addition’s foundation settles a little differently than the original slab, and the stress shows up as a diagonal crack in the drywall or exterior stucco at the transition. It’s almost never structural panic, but it is a signal the connection was never flashed or reinforced the way it should have been.
- PGT windows or doors in the addition that stick or won’t latch. When the framing of a poorly-built addition shifts, the PGT openings go slightly out of square. A window that locked smoothly for years will suddenly need two hands. We see this more in second-story additions where the original builder ran headers undersized for the span.
- Floors that dip or bounce in the addition. In San Antonio, we’re building on soil that moves. If the floor system in the addition wasn’t designed for the actual joist span, you’ll feel a soft bounce when the kids run through. It won’t fail tomorrow, but it will get worse, and it’ll telegraph into the tile and baseboard over time.
- Energy bills climbing while comfort drops. A PGT window is a good product. But a PGT window installed without proper flashing, or one that’s lost its seal, leaks air in ways you feel as a draft near the sill. An addition that’s hot in summer and cold in winter usually has insulation or sealing gaps in the transition wall, not just the glass.
- Water staining at the base of the addition’s exterior wall. This is the one to take seriously. If the sill plate wasn’t separated from wet soil properly, or the drainage plane was skipped, water wicks upward and the bottom of the wall starts to rot. You’ll see it as a hairline stain, often behind an exterior water spigot or at the lowest corner.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What's Included
For a PGT-compatible home addition in San Antonio, your written price will land between $45,000 and $130,000 depending on size, foundation type, and how much of the existing PGT window and door inventory you want to keep and tie into. A detached ADU runs $90,000 – $220,000, and that range is driven by whether you need full plumbing, a separate electrical service, and site work like grading or pier depth on our expansive clay. Every written price we hand over includes the parts, the labor, the dumpster, the protection for your floors, and the permit fees. We don’t come back after demo day with a change order because we measured the roof wrong. The work carries our 365-Day Done Right Promise: if it’s not done right, we make it right.
DIY or Call Us?
A failing PGT window in an existing wall is one thing. A failing addition, or a new ADU, is not a weekend project, and I want to be straight about that. What you can check safely: run a level across the existing PGT window sills to see if the addition has shifted, look for the diagonal seam cracks, and check the exterior base for soft wood or staining. What you should not attempt: cutting into the roof of an existing PGT-tied structure, re-flashing a transition wall, or pouring piers on San Antonio clay without knowing what the soil test showed. We’ve been called after DIY structural work more times than I’d like, and the fix always costs more than the original job would have. If you’re unsure, call (432) 233-0976 and we’ll walk the property with you before anyone swings a hammer.
FAQs
With proper foundation work for our clay soil and correct flashing at the transition seam, a San Antonio addition built with PGT windows and doors will last 50-plus years before major structural work is needed. The things that shorten that lifespan are water at the sill plate and undersized foundation systems, not the PGT glass itself. Call (432) 233-0976 and we’ll look at what you’ve got.
Yes, in most cases the structure can be repaired: releveling, seam reinforcement, re-flashing, and replacing only the failed components is a real option. If the framing is sound and the foundation movement has stabilized, a repair ranging from a few thousand to the low five figures gets you another decade or more. The honest answer depends on what’s behind the drywall, which is why we do a full inspection before quoting.
A full PGT-compatible home addition in San Antonio typically takes 10 to 16 weeks from permit approval to final walkthrough; a detached ADU runs 4 to 8 months depending on utility work and foundation depth. We schedule the noisy work around your family’s quiet hours where possible, and the crew wears shoe covers and lays drop cloths every single day. You’ll get a written timeline with the written price, before any work starts.
We stock the common PGT frame depths, flashing profiles, and sealant systems that San Antonio additions and ADUs call for, and anything we don’t carry on the truck we order by name and spec so you can verify the warranty yourself. We also work with KraftMaid, Cambria, and Silestone when the project touches the interior of the addition. Nothing is invented on site; every line item is written down before work begins.
Written by Graham Stein, Owner, Elmstead Remodeling San Antonio at Elmstead Remodeling San Antonio, serving San Antonio and nearby areas.
