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ES Windows Home Additions & ADU: The Los Angeles Owner’s Guide
Home additions and ADU construction built around ES Windows frames in Los Angeles typically run $53,100 to $153,400, with full ADU builds landing between $106,200 and $259,600 depending on square footage, foundation work, and whether you’re attaching to the existing structure or going detached. That’s the range we quote most often, and it reflects what actually happens when ES Windows openings need to be retrofitted, reframed, or expanded mid-project. Most homeowners discover this issue the hard way: the room addition is framed, the window order goes in, and the ES Windows unit measurements from five years ago don’t match what the new wall actually needs.
The telltale sign is usually a window that was never designed for a load-bearing wall or a sliding glass assembly with an ES Windows tracking channel that’s been stressed by Los Angeles sun exposure and seismic settling. We see it in neighborhoods from Eagle Rock to Mar Vista, and it’s almost always the same culprit: the original window was spec’d for a remodel, not for the structural demands of a full addition.
Which ES Windows Models This Applies To
ES Windows builds aluminum and aluminum-clad units that show up across three common Los Angeles scenarios: original mid-century homes in the hills, 1980s-90s tract builds in the Valley, and custom multi-slide installations in newer ADUs. The compatibility question isn’t about one model line. It’s about the frame depth and mullion configuration. ES Windows units installed before roughly 2010 tend to have narrower frame profiles, which matters when your addition requires tempered glass or Title 24-compliant low-E coatings that didn’t exist in the original order.
Here’s the gotcha most people don’t know: ES Windows uses a proprietary corner key and gasket system that changed around 2015. If your existing frames are pre-2015, off-the-shelf replacement sashes from aftermarket suppliers often won’t seat correctly, and you’ll end up with air leaks around the thermal break. We match by measuring the glass pack thickness and the corner key configuration, not by the sticker on the frame. For additions and ADUs, we stock the newer ES Windows-compatible hardware and can order original-spec parts directly. If the frame itself is sound, an OEM sash replacement makes sense. If the frame is compromised by Los Angeles’s combination of coastal salt air and inland dry heat, a full reframe with current ES Windows-compatible units is the honest call. Mason Remodeling is an independent contractor and not affiliated with ES Windows, which means we tell you when the OEM part is the only sensible choice and when an equivalent gets the job done for less.
Styles & brands we work with
Signs Your ES Windows Home Additions & ADU Is Failing
- Sticking or grinding when you open the sash. The aluminum track has worn or collected enough grit from Santa Ana winds that the roller or glider is dragging. Left alone, the hardware scores the track and you’re replacing the frame section, not just the roller.
- Condensation between the panes. The seal on the insulated glass unit has failed. In Los Angeles, this happens faster in homes within five miles of the coast where marine layer moisture works on the seal year-round.
- Visible gaps between the frame and your new wall rough opening. This is the addition-specific one. If the addition settles, which it does, the ES Windows frame flexes with it. Gaps at the corners mean the original rough opening wasn’t re-squared for the new structure.
- Drafts you can feel near the locking mechanism. The multi-point lock has shifted out of alignment. On ES Windows units, the lock body and the keepers are matched pairs; replacing just one side doesn’t fix the problem.
- Difficulty locking or a handle that spins without engaging. The internal gearbox in the handle has stripped. It’s a small part, but water intrusion through an unlocked window in a new addition is a fast way to rot a fresh sill.
See the difference
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AfterReplacement Cost & What’s Included
For a window replacement inside a Los Angeles addition or ADU project, installed pricing runs $5,310 to $17,700 depending on the size, glass package, and whether we’re pulling the whole frame or swapping hardware and sashes. If the ES Windows unit sits in a wall we’re already reframing for the addition, the window cost folds into the broader $53,100 to $153,400 project range. If you need a standalone window swap, the line item is separate and written out before we start.
What you’re paying for: the ES Windows-compatible unit or OEM part, new flashing and weather barrier at the rough opening, corrected shimming so the frame sits square in the wall, and disposal of the old unit. Every price is in writing before work begins, and the work is covered by the 365-Day Done Right Promise. If the window leaks, sticks, or fails within 365 days of completion, we return and fix it at no cost. Our crew members are background-checked, identity-verified, and you’ll know their name and see their photo before they ever knock on the door.
DIY or Call Us?
You can safely do a few things without touching the frame: clean the tracks, visually inspect the weatherstripping, and note where drafts are coming from. What you shouldn’t do is pull the sash on an ES Windows unit unless you’ve done it before. The corner keys and balance system are under tension, and a slipped glass pack on a second-story addition is a serious injury waiting. Isaac Pruett has pulled enough of these apart to know that the ten-minute YouTube fix usually turns into a three-hour job once the hidden clip breaks.
If the addition or ADU is already under construction and a window isn’t fitting, don’t force it. Call us at (803) 680-2547. We’ll tell you over the phone whether it’s a measurement issue, a parts issue, or a framing issue, and then we’ll schedule the walkthrough with a written price. Know who’s coming, know what it costs, know it’s backed up. Everything else is just noise.
FAQs
With proper installation, ES Windows aluminum units in Los Angeles last 25 to 40 years, but the seals and hardware typically need attention between years 15 and 20, especially in homes within five miles of the coast where salt air accelerates hardware corrosion. If the frames are straight and the thermal breaks are intact, replacing sashes and hardware extends the life another decade or more.
Yes, when the frame is square and the glass itself is intact, we can replace the lock gearbox, rollers, gliders, weatherstripping, and the insulated glass unit as separate repairs, which usually runs $470 to $2,125 for targeted hardware and seal work in Los Angeles. The decision to repair versus replace depends on whether the frame corners have opened up, because once the corner keys loosen, repair costs approach replacement cost quickly.
A standard same-size window swap takes one to two days for most Los Angeles additions, including flashing, shimming, and interior trim rework; a full rough-opening reframe takes three to five days depending on the exterior finish and whether stucco or siding needs patching. We include the schedule in your written price before any work begins.
We stock the common failure items: multi-point lock bodies, handles, roller and glider sets, and weatherstripping for the ES Windows configurations we see most often in Los Angeles, and we can source OEM insulated glass units within a few days when the glass pack has failed. If you’re not sure what you need, call (803) 680-2547 and describe the symptoms; we’ll tell you whether it’s a stock part or an order item before you commit to anything. Estimates are free.
Written by Isaac Pruett, Owner, Mason Remodeling at Mason Remodeling, serving Los Angeles and nearby areas.
