Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
ECO Window Systems Home Additions & ADU: The Los Angeles Owner’s Guide
We install and build ECO Window Systems-compatible home additions and ADUs across Los Angeles, with full projects typically landing between $53,100 and $153,400 depending on square footage, foundation work, and how much of the existing structure ties into the new space. When a homeowner calls us about an ECO Window Systems addition, it’s usually one of two things: either a window or door unit in the addition has failed (seal fog, a crank mechanism stripped, a slider that suddenly binds), or they’re planning fresh and want the window package matched to ECO specs from day one. Trevor Nash has been on enough Los Angeles job sites to know both calls well.
Which ECO Window Systems Models This Applies To
ECO Window Systems builds vinyl and aluminum window and door lines that show up in a lot of Southern California additions and ADU builds, especially where Title 24 energy compliance pushed the window package toward higher-performance glass. The compatibility gotcha we run into most often: ECO’s sliders and casements use different frame depths depending on whether they were ordered as new-construction flanged units or retrofit block-frame replacements. If you’re adding onto a mid-century Los Angeles house with stucco over wood framing, the original windows are almost always block-frame; if the addition is stick-built with plywood sheathing, the ECO units are flanged. The two don’t swap without furring strips or new flashing, and guessing wrong usually means water intrusion at the sill within the first rainy season. Check the sticker on the inside edge of the sash or the head jamb; ECO prints a manufacturing code that includes the series and the glass package, and we can match it by photo before we ever dispatch a truck.
On the OEM-versus-aftermarket question: for glass units, balances, and weatherstripping on ECO Window Systems products, we use genuine ECO parts whenever the unit is still under warranty or when the frame is in good shape and the failure is isolated. For hardware like crank operators and locking handles on older ECO lines that have been discontinued, we use quality aftermarket equivalents from the same trade manufacturers that supply the Southern California window industry. We’ll tell you which one applies before we order anything, and the price we quote is the price on the invoice.
Styles & brands we work with
Signs Your ECO Window Systems Home Additions & ADU Is Failing
- Fog or haze between the panes that never clears. That’s a broken seal on the insulated glass unit. In Los Angeles, where we get hot days and cool nights even inland, the thermal cycling kills seals faster than in milder climates. The glass has to be replaced as a unit; no amount of cleaning fixes it.
- A slider or casement that suddenly grinds or won’t stay open. On ECO units, this is typically a failed balance or operator gear, not the frame. We see it most on windows that face full afternoon sun in neighborhoods like Sherman Oaks or Torrance, where the heat ages the nylon components inside the hardware.
- Drafts you can feel with the window closed and locked. Weatherstripping on vinyl windows compresses over time, and once it’s flat, the window loses its air seal. ECO’s bulb-style gaskets are replaceable without pulling the sash, which is a repair we do same day.
- Water staining on the interior drywall beneath a window. This is rarely the window itself; it’s the flashing or the sill pan underneath it. Los Angeles doesn’t get a lot of rain, but when it comes, a poorly flashed addition window shows its leaks fast.
- The frame is square but the sash won’t seat at the top or bottom. That’s usually a shifted header or settled framing above the window, which happens in Los Angeles ADUs built over expansive soil or on older foundations. The window gets blamed, but the fix starts at the framing.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For LOS ANGELES replacement work on ECO Window Systems units inside an existing addition or ADU, you’re looking at these installed price ranges:
- Sealed glass unit replacement (fogged pane): $470 – $2,125 per window, depending on glass size, Low-E coating, and whether it’s tempered code glass near a door or in a wet zone.
- Complete window replacement with ECO-compatible unit: $5,310 – $17,700 per opening, including removal, flashing, and stucco or drywall touch-up.
- Full home addition or ADU build with ECO-aligned window package: $53,100 – $153,400 for the project, with the window and door line item broken out in your written estimate.
What drives the spread: access (second-story ADU windows over a sloped yard cost more to set), stucco matching on older Los Angeles homes (color-matching acrylic finish isn’t free), and whether the replacement triggers current Title 24 energy requirements. Every quote we write includes parts, labor, disposal, and the flashing work; our 365-Day Done Right Promise covers the installation in writing, and the glass units carry the manufacturer’s own warranty alongside ours. If a window leaks or a seal fails inside that year, we come back and fix it at no charge. No re-inspection fee, no service call.
DIY or Call Us?
Some things on an ECO Window Systems addition you can check yourself without risk: take photos of the manufacturing sticker, note where the fog or draft is, and check whether the weep holes at the bottom of the frame are clogged. That’s useful information when you call. Opening the sash and swapping a balance cartridge on a casement is a different story; those are under tension, and a slip can take the sash out of your hands and bend the frame, or take a chunk out of your finger. Any work involving removal of the window, flashing, or stucco should be left to someone who does it every week. We’re at (213) 277-6578, and a live person answers; tell us what the window is doing and we’ll give you a number first, then pick up the tools.
FAQs
Figure 20 to 30 years for the frames, with glass seals typically failing somewhere in the 12-to-18-year range in Los Angeles heat. The frame will usually outlast the seals and hardware, which is why replacing the glass unit or the operator is often smarter than replacing the whole window. Call (213) 277-6578 and we’ll tell you which side of that line your window is on.
Yes, if the failure is the seal, the balance, the weatherstripping, or the crank hardware. Those are component repairs we do routinely. If the frame itself is cracked, warped, or pulling away from the rough opening, the window gets replaced. We’ll show you the difference before we quote anything.
Most single-window replacements on a Los Angeles ADU run a half day to a full day, including flashing and stucco touch-up. Larger multi-window jobs or anything involving structural header repair goes longer, and we’ll tell you the window we’ll show up in before we start.
We stock common balance cartridges, operators, locks, and weatherstripping for the ECO lines we see most around Los Angeles. Glass units are ordered to size and usually arrive within a week. For discontinued ECO hardware, we source quality aftermarket equivalents from the same trade suppliers that serve the Southern California window industry.
Written by Trevor Nash, Owner, Penhallow Remodeling Los Angeles at Penhallow Remodeling Los Angeles, serving Los Angeles and nearby areas.
