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ECO Window Systems Home Additions & ADU: The San Diego Owner’s Guide
Home additions and ADU construction involving ECO Window Systems products in San Diego typically run between $53,100 and $153,400, with most projects landing in the $70,000 to $110,000 range depending on square footage, permitting complexity, and foundation work. We’re an independent contractor serving San Diego County and we install, service, and replace ECO Window Systems windows, doors, and glass packages as part of larger addition and ADU builds. We’re not affiliated with ECO Window Systems, but we work with their products every week, and we know exactly what fails, what lasts, and what a fair price looks like in this market.
Most San Diego homeowners call us halfway through an addition or ADU project. The framing is up, the windows are ordered, and then something doesn’t fit, or a door binds, or the glass package arrives with the wrong low-E coating for the coastal exposure. Sometimes the problem shows up years later: fogging between panes, warped frames from the sun off Mission Bay, or hardware that no longer seals tight. Either way, you need someone who knows the product line, not someone who’s going to read the installation manual in your driveway.
Key takeaways:
- Installed ECO Window Systems replacement parts for additions and ADUs in San Diego run $53,100 to $153,400 for full projects; individual window and door swaps fall lower.
- We carry common ECO Window Systems hardware, weatherstripping, and balance assemblies on our trucks.
- Written price before work starts, every time. That’s not a promotion. That’s how Isaac Pruett has run Mason Remodeling Co San Diego since day one.
Which ECO Window Systems Models This Applies To
ECO Window Systems builds several product lines, and the part you need depends on which one you have. The most common lines we see in San Diego additions and ADU projects are the 400 Series, the 800 Series, and their contemporary line with narrow sightlines. Each series uses different hardware, different weatherstripping profiles, and different balance systems. If you grab a 400 Series sash lock for an 800 Series window, it won’t seat correctly, even though both parts look nearly identical at a glance.
Here’s the compatibility check we run on every service call. Open the window or door and look for the manufacturer label, usually etched into the glass corner or printed on a sticker along the frame edge. The label will show a series number and a glass package code. That code tells us the low-E coating, the argon fill, and the spacer type. Matching the glass package matters in San Diego, because a double-pane unit without the right low-E on a west-facing addition in Clairemont or Point Loma will cook the room by August. Aftermarket glass is fine when it matches the original spec. When it doesn’t, you get condensation, fade damage, and a room that never holds temperature.
One more thing worth knowing: ECO Window Systems changed their hardware supplier around 2019. Pre-2019 windows use a different lock geometry than post-2019 windows. We’ve had homeowners buy the right series part online and still get the wrong fit because the listing didn’t distinguish between hardware generations. That’s a hundred dollars wasted and another week with a window that won’t latch.
Styles & brands we work with
Signs Your ECO Window Systems Home Additions & ADU Is Failing
- Condensation or fog between the glass panes. The seal on the insulated glass unit has failed. Once the desiccant inside the spacer is saturated, no amount of wiping fixes it. The glass unit needs replacement, not the whole frame.
- The window or door won’t stay open or closed. The balance system or the operator mechanism has worn out. ECO Window Systems uses spiral balances on many double-hung units, and in coastal San Diego air, the springs inside corrode faster than they would inland.
- You can feel air moving around the edges on a still day. The weatherstripping has compressed or dry-rotted. This is the most common failure we see in San Diego ADU projects within five years of install, especially on south-facing exposures.
- The frame looks chalky, pitted, or warped. UV degradation from constant sun, especially in East County, breaks down the frame finish and can warp vinyl and composite materials.
- Hardware snaps or the lock won’t engage. Forced operation, salt air corrosion, or the pre-2019 hardware issue we mentioned. A window that won’t lock is a security problem, not a cosmetic one.
See the difference
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AfterReplacement Cost & What’s Included
A full addition or ADU with ECO Window Systems products in San Diego runs $53,100 to $153,400. That range covers everything from a compact single-room bump-out with three or four windows to a complete 800-square-foot ADU with a full kitchen, bath, and dedicated HVAC. The biggest cost drivers are foundation type, kitchen and bath count, utility connections, and whether your property sits within San Diego’s coastal overlay zone, which adds permit review time and sometimes stricter energy code requirements.
When the scope is a window or door replacement inside an existing ECO Window Systems addition, the price drops significantly. A standard double-hung replacement runs $5,310 to $17,700 installed. A full-frame window replacement with stucco patch-back in an older San Diego home runs higher because we’re cutting out the old frame, setting the new one, flashing it properly, and making the exterior watertight. We don’t do insert-only installs when the original flashing is failing, because that’s how you end up with water behind the stucco and a mold problem no one finds until the drywall sags.
Every price we quote is written, line-itemed, and delivered before work starts. Labor and parts are listed separately. And every installation is covered by the 365-Day Done Right Promise: if the work isn’t right within a year of completion, Mason Remodeling Co San Diego fixes it at no cost. No dispute process. No conditions.
DIY or Call Us?
There are a few things you can safely check yourself. Clean the tracks on sliding doors and windows; San Diego dust and pollen build up fast and cause binding. Check visible weatherstripping for compression or gaps. Confirm that weep holes at the bottom of the frame aren’t clogged, especially after Santa Ana winds blow debris across the county.
Beyond that, this work gets serious fast. Window and door replacement on an addition or ADU involves flashing, waterproofing, and sometimes structural header work. We install windows and doors using the ERA/Texas Flashing method and closed-cell sealant on every frame, because we’ve seen what happens when installers shortcut the flashing on a coastal Saltbox in La Jolla. If you’re dealing with tempered glass, low-E coatings, or a failed seal on a second-story unit, don’t learn on your own house. Call (619) 673-9302. Tell me what’s broken. I’ll tell you what it takes.
FAQs
The frames on ECO Window Systems windows typically last 20 to 30 years in San Diego’s climate, but the glass seals and moving hardware generally need attention around the 10 to 15 year mark, especially on south- and west-facing exposures where UV and heat cycling are hardest. Coastal homes in areas like Ocean Beach and Imperial Beach see faster hardware corrosion. Call (619) 673-9302 if your seal has failed, and we’ll quote the replacement honestly.
Yes, in many cases. Weatherstripping, balance assemblies, and lock hardware can all be replaced individually without replacing the whole window, and that’s usually a fraction of the cost of a full unit swap. If the glass seal has failed, the insulated glass unit gets replaced, not repaired. Call (619) 673-9302 and we’ll tell you which bucket your window falls into.
A single window or door replacement typically takes one day, including removal, installation, flashing, and interior finish work. A full ADU window package during new construction typically takes two to four days depending on unit count. Written estimates always include a schedule, so you know before we start exactly how many days to plan around.
Our trucks carry common ECO Window Systems weatherstripping, lock assemblies, balance systems, and hardware for the 400 and 800 Series. Unusual glass packages and specialty hardware get ordered from our supplier network, and we handle the ordering and lead time so you’re not chasing parts yourself. We also work with KraftMaid, Cambria, and Silestone for finish materials when your addition or ADU scope includes cabinetry and counters.
Written by Isaac Pruett, Owner, Mason Remodeling Co San Diego at Mason Remodeling Co San Diego, serving San Diego and nearby areas.
