Windows & Doors
Retrofit window replacement
Older windows replaced with white vinyl retrofit windows. The stucco stays intact.
Window Replacement in Los Angeles & the San Gabriel Valley
Full window replacement is the job for old single-pane aluminum sliders, frames that have corroded or warped, rooms that bake in the afternoon sun and street noise that comes straight through the glass. APL Glass & Windows installs Milgard windows in vinyl and aluminum across Los Angeles County, the San Gabriel Valley and Orange County.
- C-17 Lic. #1007507
- Fully insured
- Most jobs in 1-2 days
- English · Tiếng Việt · 中文
A retrofit window (also called a flush-fin or Z-bar window) has a fin that covers the old frame from the outside. The old sash and glass come out, the old frame stays in the wall, and the new window seals against it. Nothing is cut out of the stucco, no drywall or trim is disturbed, and there is no patching or painting afterward. New-construction windows with a nail fin are the alternative when the opening is being changed or the old frame has rotted.
Estimates are free and done on site so we can check each opening. We are a family-run shop in Rosemead since the 1990s, licensed C-17 #1007507 and fully insured, and we speak English, Tiếng Việt and 中文.
Frame and glass choices
What a retrofit install day looks like
The crew arrives with the windows already made to the measurements from the estimate visit. One opening at a time, we remove the old sash and glass, clean the old frame and check it for level. The new Milgard unit is set in, shimmed square, screwed through its frame into the old frame, and the exterior fin is sealed to the stucco with exterior sealant. Inside, the gap is covered with trim or sealant.
How many windows we finish in a day depends on size, access and how the old windows come out; a typical house takes a day or two, and we go over the plan before we start. Each window is left locked and working before we move to the next, so the house is secure at the end of every day.
Replacement windows in California have to meet the state energy code, which is why Low-E dual-pane glass is standard on the units we install, and many cities in Los Angeles County want a permit for full window replacement. The benefits are plain: dual-pane Low-E glass keeps summer heat out and winter heat in, the sealed air space cuts traffic and neighbor noise, and new sashes glide and lock the way they should.
Before and after
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After 
Before 
After 
Before Window Replacement: our work
How it works
From photo to finished job
- 1
Call (626) 571-0135 or send photos of the windows you want replaced and we will set up a free on-site estimate.
- 2
We measure every opening, go over frame colors, glass options and styles, and give you a written price per window.
- 3
The Milgard windows are ordered to size and we schedule the install for when they arrive.
- 4
Install day: old sashes out, new windows in, sealed and trimmed, with the old glass and frames hauled away.
Our work
Window Replacement projects
Real jobs from our crew. Photos are ours, not stock.
Windows & Doors
Arched retrofit window
Dark-frame arched window replaced with a white retrofit unit, matched to the arch.
Windows & Doors
Window glass replacement
Glass-only replacement in a tall window, existing frame kept.
Questions customers ask
What is a retrofit window and how is it different from new construction?
A retrofit window has a flush fin that sits over the old frame from the outside, so the stucco is never cut. A new-construction window has a nail fin that goes under the stucco and building paper, which means tearing out around the opening and re-stuccoing. For an existing home with sound frames, retrofit is faster, cleaner and costs less.
Why Milgard?
Milgard is the brand we install: a West Coast manufacturer with vinyl and aluminum lines in every common style, and retrofit frames made for the stucco homes we work on. Tell us what you need and we will point you to the right Milgard product.
What drives the price of window replacement?
The number and size of windows, the frame material (vinyl costs less than aluminum), the glass package (Low-E, obscure and tempered add cost) and any custom shapes or colors. The estimate lists each opening on its own line so you can see where the money goes.
Will the stucco or the inside walls be damaged?
No. A retrofit install keeps the stucco, the drywall and the trim exactly as they are. The only visible change outside is the new frame and its fin over the old one.
Do new windows really make the house quieter and cooler?
Yes, and coming from old single-pane aluminum windows the difference is immediate. Dual-pane glass with a sealed air space blocks more heat and more sound than a single sheet, and the Low-E coating reflects sun heat before it enters the room.
Do I need a permit to replace windows?
Many cities in Los Angeles County require one for full window replacement, and the new windows must meet California’s energy code, which Milgard’s dual-pane Low-E units do. Glass-only replacement in an existing frame generally does not. We tell you what your city requires when we quote.
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Free estimates
Free estimate for window replacement
Send photos of the opening or the damage, or book a free on-site visit. We quote during business hours.
- On-site or from photos, no obligation
- Most common jobs done in 1-2 days
- We speak English, Tiếng Việt and 中文.
Get your free estimate
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