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Mr-Glass Home Additions & ADU: The Austin Owner’s Guide
If you’ve got a Mr-Glass home addition or ADU and something’s failing, you already know the feeling: the door sticks, the seam opens, the wall pulls away from the house where the old framing meets the new. In Austin, a full Mr-Glass home addition or ADU replacement typically runs $45,000 – $130,000 installed, depending on square footage, foundation work, and how much of the original connection point needs to be rebuilt. Most homeowners discover the problem the same way: a crack appears along the transition line where the addition ties into the original structure, or the ADU’s roofline starts sagging just enough to notice from the driveway.
We’re Penhallow Remodeling Austin, an independent contractor. We’re not affiliated with Mr-Glass, but we work on their additions and ADUs regularly, and we still install hardware and connectors from KraftMaid cabinetry lines, plus countertop systems from Cambria and Silestone when those surfaces are tied into the structure. Trevor Nash built this company on a simple idea: tell you what it costs on day one, then do exactly what we said we’d do.
Which Mr-Glass Models This Applies To
Mr-Glass home additions and ADUs in the Austin market fall into two broad construction types: site-built additions tied directly to the main house’s roofline, and detached or semi-attached ADUs that look like standalone units but share at least one wall line or utility run with the primary structure. The failing part is rarely the “Mr-Glass” label itself; it’s the connection hardware, the tie-in framing, or the flashing where the old roofline meets the new one.
Here’s the gotcha most owners don’t know: Mr-Glass additions built before roughly 2015 often used a lighter-gauge metal connector at the roofline transition, and Texas summers bake those connectors until they flex. Newer models use a heavier L-shaped bracket with a rubberized gasket. You can tell which you have by looking at the seam from inside the attic: if you see bare metal with paint flaking, it’s the older spec. The OEM replacement part is still available, but a quality aftermarket bracket with a wider footprint and galvanized coating holds up better in Austin’s heat and humidity cycles. We keep the aftermarket version on the truck because it outperforms the original.
Styles & brands we work with
Signs Your Mr-Glass Home Additions & ADU Is Failing
- A crack along the ceiling where the addition meets the original house. This is the big one. The two structures settle at different rates, and Austin’s clay soil makes it worse. The crack appears because the connector hardware has worked loose or the framing behind it has shifted.
- Doors inside the addition that stick in summer and swing free in winter. That’s moisture movement. The addition’s framing pulls against the original structure when humidity swings hit 40-point spreads between June and December. If it’s been getting worse for three summers straight, the tie-in is failing.
- Water staining along the transition line, especially after a hard rain. The flashing between the old roofline and the new one wears out. It’s not dramatic. It’s a slow drip that shows up as a tea-colored stain on drywall or ceiling texture.
- A visible gap at the exterior transition point, where the siding or stucco of the addition meets the main house. If you can see daylight or slide a putty knife into the seam, the flexible sealant has failed. Water’s getting in, and the gap only widens.
- Popping or snapping sounds from the attic over the addition at night. Metal connectors cooling down after a 100-degree day make noise. Occasional pops are normal. Consistent popping in the same spot means a bracket is rubbing and fatiguing.
See the difference
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After
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AfterReplacement Cost & What’s Included
In Austin, a Mr-Glass home addition or ADU replacement runs $45,000 – $130,000, and the spread comes down to four things: square footage, whether the foundation under the addition needs releveling, how much of the original tie-in framing has to be opened up and rebuilt, and whether you’re replacing just the failing connection or reconstructing the entire addition shell.
| Scope of Work | Typical Austin Installed Price |
|---|---|
| Full home addition replacement | $45,000 – $130,000 |
| ADU construction (new build) | $90,000 – $220,000 |
| Tie-in hardware update only | $3,000 – $8,000 |
| Flashing and seal replacement | $800 – $2,500 |
Every quote we write includes labor, materials, and the permit work. You get a written price before we start, and that’s the number on the invoice. If something fails inside the first year, our 365-Day Done Right Promise says we come back and fix it at no charge, in writing, on every project. No service call fee, no re-inspection charge.
DIY or Call Us?
You can safely check a few things yourself. Go up into the attic with a flashlight and look at the transition line. If you see cracked sealant, loose fasteners, or a gap you can fit a business card into, that’s worth a closer look. You can also check the exterior seam for daylight and run a hose along it during a dry week to see if water finds its way inside.
What you shouldn’t do is open up drywall or start pulling framing loose to “see what’s going on.” The connection between an addition and the original structure is load-bearing. The wall or roofline you’re inspecting is holding weight, and Austin’s clay soil means everything under it is moving more than you’d think. That’s not a handyman job. That’s a structural repair. Call us at (325) 225-5429 and we’ll walk you through what we’d check first.
FAQs
The addition shell should last 40 to 60 years, but the tie-in hardware and flashing typically need attention every 15 to 20 years in Austin because of the heat and soil movement. Call (325) 225-5429 if you’re seeing cracks or gaps at the transition line, and we’ll give you an honest read on whether it’s cosmetic or structural.
If the framing is sound and the problem is the connector hardware or flashing, it’s a repair job in the $800 to $8,000 range. We’d only talk about full replacement if the framing has rotted or the foundation under the addition has shifted beyond correction. Call us at (325) 225-5429 and we’ll tell you which situation you’re in before you spend a dime.
A tie-in hardware update takes one to two days. A full addition replacement runs four to eight weeks depending on scope and permitting. We’ll put the timeline in writing with the price, and our crews show up in the window we gave you. Call (325) 225-5429 for a free estimate and a real schedule.
We carry the aftermarket tie-in connectors, flashing, and sealants on the truck. If you need OEM Mr-Glass parts specifically, we can order them, but we’ll usually recommend the aftermarket version because it’s galvanized and holds up better in Austin humidity. Call (325) 225-5429 and ask for Trevor or a member of his crew; we’ll tell you what you’re looking at before we even schedule a visit.
Ready to get this fixed? Call (325) 225-5429 for a free estimate. We’ll put the price in writing before any work starts, and if it’s not done right, we’ll make it right. That’s the Kingswell Way, and it’s been the rule since 2004.
Written by Trevor Nash, Owner, Penhallow Remodeling Austin at Penhallow Remodeling Austin, serving Austin and nearby areas.
